ACI 116R-00

Cement and Concrete Terminology

Reported by ACI Committee 116

Hamid Farzam Chairman

Glen Bollin Richard H. Howe Joaquin Marin Bernard J. Erlin Henri L. Isabelle Bryant Mather Fred K. Gibbe Lawrence J. Kaetzel Alvaro G. Meseguer Robert L. Henry Tarek S. Khan Richard C. Mielenz Mark B. Hogan James R. Libby Austin H. Morgan, Jr. Edward P. Holub Mark D. Luther Todd Rutenbeck

FOREWORD This report is the authoritative glossary for cement and concrete technology. It is to be used generally and specifically in ACI tech- nical communications, correspondence, and publications. One mission of Committee 116 is to produce and maintain a list of terms with their meaning in the field of cement and concrete technology. Committee 116 has tried to produce a glossary that will be useful, comprehensive, and up-to-date. It recognizes, however, that the listing may not be complete and that some definitions may be at variance with some commonly accepted meanings. Users of the glossary are invited to submit suggestions for changes and additions to ACI Headquarters for consideration by Com- mittee 116 when preparing future editions. In the event that a user disagrees with any of the definitions, it is hoped that the reasons for such will be given to the committee. The committee is aware that some of the definitions included may seem entirely self-evident to an expert in the concrete field. This occurs because no term has been discarded if there was reason to believe it would appear to be technical in nature to a casual reader of the ACI literature. The committee voted to use the following procedural rules: 1. Each definition shall be stated in one sentence; 2. Each definition shall consist of the term printed in boldface, a dash, and the definition statement; 3. The definition statement shall not repeat the term and should state the class or group and identify the features unique to the term; as “mathematics—the science of numbers and spaces”; 4. Verbs should be stated in the infinitive rather than the participle; for example the term to be defined should be “abrade” not “abrading”; 5. Notes may be appended to definition statements; 6. Cross references may take the place of a definition as “green concrete—see concrete, green.” They also may call attention to related items as “flint—a variety of chert. (See also chert).” Where the committee has found two or more terms with the same meaning, the definition is given where the preferred term appears, the synonyms are cross referenced to the preferred term, and in many cases, the fact is stated; 7. Generally, where there are a number of terms, the last word of which is the same, the definitions are given where the terms are listed in the inverted form, as “cement, low-heat” rather than “low-heat cement,” but under the latter entry, there will be a cross ref- erence “see cement, low-heat;” and 8. In selecting terms and definitions, there shall be coordination with the terminology subcommittees of ASTM Committees C-1 on Cement, and C-9 on Concrete and Concrete Aggregates. The invaluable contributions of the past chairmen of Committee 116, B. J. Erlin, R. C. Mielenz, D. L. Bloem, W. H. Price, R. E. Davis, Jr., J. R. Dise, K. F. Gibbe, Robert L. Henry, M. D. Luther, B. Mather, and E. Senbetta, those of the present members of the committee, as well as the diligent efforts of William Lorman and Lewis H. Tuthill, are gratefully acknowledged. For drafting this edition, all members, both associates and voting, participated.

ACI Committee Reports, Guides, Standard Practices, and Commentaries are intend- ACI 116R-00 supersedes ACI 116R-90 and became effective March 16, 2000. ed for guidance in planning, designing, executing, and inspecting construction. This Copyright  2000, American Concrete Institute. document is intended for the use of individuals who are competent to evaluate the sig- All rights reserved including rights of reproduction and use in any form or by any nificance and limitations of its content and recommendations and who will accept re- means, including the making of copies by any photo process, or by electronic or sponsibility for the application of the material it contains. The American Concrete mechanical device, printed, written, or oral, or recording for sound or visual reproduc- Institute disclaims any and all responsibility for the stated principles. The Institute shall tion or for use in any knowledge or retrieval system or device, unless permission in not be liable for any loss or damage arising therefrom. writing is obtained from the copyright proprietors. Reference to this document shall not be made in contract documents. If items found in This document has been approved for use by agencies of the Department of Defense this document are desired by the Architect/Engineer to be a part of the contract documents, and for listing in the DoD Index of Specifications and Standards. they shall be restated in mandatory language for incorporation by the Architect/Engineer.

116R-1 Abram’s

A admixture, air-entraining—an admixture that causes the development of a system of microscopic air bub- Abrams’ law—see law, Abrams’. bles in concrete, mortar, or cement paste during mix- abrasion damage—see damage, abrasion. ing, usually to increase its workability and resistance abrasion resistance—see resistance, abrasion. to freezing and thawing. (See also air, entrained.) absolute specific gravity—see specific gravity, absolute. admixture, retarding—an admixture that causes a de- absolute volume—see volume, absolute. crease in the rate of hydration of the hydraulic cement absorbed moisture—see moisture, absorbed. and lengthens the time of setting. absorbed water—see moisture, absorbed. admixture, water-reducing—an admixture that either absorption—the process by which a liquid is drawn into and increases slump of freshly mixed mortar or concrete tends to fill permeable voids in a porous solid body; also, without increasing water content or maintains slump the increase in mass of a porous solid body resulting from with a reduced amount of water, the effect being due to the penetration of a liquid into its permeable voids. factors other than air entrainment. abutment—in bridges, the end structure (usually of con- admixture, water-reducing (high-range)—a water-re- crete) that supports the beams, girders, and deck of the ducing admixture capable of producing large water re- bridge, or combinations thereof, and sometimes retains duction or great flowability without causing undue set the earthen bank or supports the end of the approach pave- retardation or entrainment of air in mortar or concrete. ment slab; in prestressing, the structure against which the adobe—unburnt brick dried in the sun. tendons are stressed in producing pretensioned precast adsorbed water—see water, adsorbed. members or post-tensioned pavement; and in dams, the adsorption—development (at the surface of either a liquid side of the gorge or bank of the stream against which a or solid) of a higher concentration of a substance than ex- dam abuts. ists in the bulk of the medium; especially formation of one accelerating admixture—see admixture, accelerating. or more layers of molecules of gases, of dissolved sub- stances, or of liquids at the surface of a solid (such as ce- acceleration—increase in velocity or in rate of change, espe- ment, cement paste, or aggregates), or of air-entraining cially the quickening of the natural progress of a process agents at the air-water interfaces; also, the process by such as setting or strength development (hardening) of which a substance is adsorbed. (See also water, ad- concrete. (See also admixture, accelerating.) sorbed.) accelerator—see admixture, accelerating. advancing-slope grouting—see grouting, advancing-slope. accidental air—see air, entrapped. advancing-slope method—see method, advancing-slope. acrylic resin—see resin, acrylic. aerated concrete—see concrete, cellular and concrete, addition—a material that is interground or blended in limit- foamed. ed amounts into a hydraulic cement during manufacture A/F ratio—see ratio, A/F. either as a “processing addition” to aid in manufacturing afwillite—a mineral with composition 3CaO · 2SiO2 · 3H2O and handling the cement or as a “functional addition” to occurring naturally in South Africa, Northern Ireland, and modify the use properties of the finished product. California, and artificially in some hydrated portland ce- advancing-slope grouting—see grouting, advancing-slope. ment mixtures. additive—see agent. agent—a general term for a material that may be used either adhesion—the state in which two surfaces are held together as an addition to cement or an admixture in concrete; for by interfacial effects that may consist of molecular forces, example, an air-entraining agent. interlocking action, or both. agent, air-entraining—see admixture, air-entraining. adhesives—the group of materials used to join or bond simi- agent, bonding—a substance applied to a suitable sub- lar or dissimilar materials; for example, in concrete work, strate to create a bond between it and a succeeding layer. the epoxy resins. agent, parting—see agent, release (preferred term). adiabatic—a condition in which heat neither enters nor agent, release—material used to prevent bonding of con- leaves a system. crete to a surface. (See also bond breaker and oil, adiabatic curing—see curing, adiabatic. form.) adjustment screw—see screw, adjustment. agent, surface-active—a substance that markedly affects admixture—a material other than water, aggregates, hy- the interfacial or surface tension of solutions when draulic cement, and fiber reinforcement, used as an ingre- present even in low concentrations. dient of a cementitious mixture to modify its freshly agent, wetting—a substance capable of lowering the sur- mixed, setting, or hardened properties and that is added to face tension of liquids, facilitating the wetting of solid the batch before or during its mixing. surfaces, and permitting the penetration of liquid into admixture, accelerating—an admixture that causes an the capillaries. increase in the rate of hydration of the hydraulic ce- agglomeration—a gathering into a ball or mass. ment and thus shortens the time of setting, increases aggregate—granular material, such as sand, gravel, crushed the rate of strength development, or both. stone, crushed hydraulic-cement concrete, or iron blast-

116R-2 ACI COMMITTEE REPORT air

furnace slag, used with a hydraulic cementing medium to aggregate interlock—the effect of portions of aggregate produce either concrete or mortar. (See also aggregate, particles from one side of a joint or crack in concrete pro- heavyweight and aggregate, lightweight.) truding into recesses in the other side of the joint or crack aggregate, angular—aggregate particles that possess so as to transfer load in shear and maintain alignment. well-defined edges formed at the intersection of roughly aggregate transparency—discoloration of a concrete sur- planar faces. face consisting of darkened areas over coarse aggregate aggregate, coarse—aggregate predominantly retained particles immediately below the concrete surface. on the 4.75 mm (No. 4) sieve, or that portion retained agitating speed—see speed, agitating. on the 4.75 mm (No. 4) sieve. (See also aggregate.) agitating truck—see truck, agitating. aggregate, crusher-run—aggregate that has been me- agitation— chanically broken and has not been subjected to sub- 1. the process of providing motion in mixed concrete just sequent screening. sufficient to prevent segregation or loss of plasticity; aggregate, dense-graded—aggregates graded to pro- and duce low void content and maximum density when 2. the mixing and homogenization of slurries or finely compacted. (See also aggregate, well-graded.) ground powders by either mechanical means or injec-

 
     tion of air. (See also agitator.)       agitator—a device for maintaining plasticity and prevent-       µ ing segregation of mixed concrete by agitation. (See also  !      agitation.)        µ aids, grinding—materials used to expedite the process of  " 

 
 grinding by eliminating ball coating, dispersing the finely aggregate, gap-graded—aggregate graded so that cer- ground product, or both. tain intermediate sizes are substantially absent. air— aggregate, heavyweight—aggregate of high density, air, accidental—see air, entrapped (preferred term). such as barite, magnetite, hematite, limonite, ilmenite,
 

 # # # $%$$      & iron, or steel, used in heavyweight concrete. # # #%  ' % %& aggregate, lightweight—aggregate of low density, such $% ( %(#&#  ! #$) as: a) expanded or sintered clay, shale, slate, diatoma- *  * µ*      # ceous shale, perlite, vermiculite, or slag; b) natural  " 
 
  pumice, scoria, volcanic cinders, tuff, and diatomite; air, entrapped—air voids in concrete that are not pur- and c) sintered fly ash or industrial cinders, used in posely entrained and that are larger, mainly irregular in lightweight concrete. shape, and less useful than those of entrained air; and aggregate, mineral—aggregate consisting essentially of 1 mm or larger in size. inorganic nonmetallic rock materials, either natural or air blow pipe—air jet used in shotcrete gunning to remove crushed and graded. rebound or other loose material from the work area. aggregate, normalweight—aggregate that is neither air-blown mortar—see shotcrete (preferred term). heavyweight nor lightweight. air content—the volume of air voids in cement paste, mor- aggregate, open-graded—aggregate in which the voids tar, or concrete, exclusive of pore space in aggregate par- are relatively large when the aggregate is compacted. ticles; usually expressed as a percentage of total volume aggregate, reactive—aggregate containing substances of the paste, mortar, or concrete. capable of reacting chemically with the products of air-cooled blast-furnace slag—see blast-furnace slag. solution or hydration of the portland cement in con- air entraining—the capability of a material or process to de- crete or mortar under ordinary conditions of exposure, velop a system of microscopic bubbles of air in cement resulting in some cases in harmful expansion, crack- paste, mortar, or concrete during mixing. (See also air en- ing, or staining. trainment.) aggregate, refractory—aggregate having refractory air-entraining agent—see admixture, air-entraining. properties that, when bound together into a conglom- air-entraining hydraulic cement—see cement, air-en- erate mass by a matrix, forms a refractory body. training hydraulic. aggregate, single-sized—aggregate in which a major air entrainment—the incorporation of air in the form of mi- portion of the particles is in a narrow size range. croscopic bubbles (typically smaller than 1 mm) during aggregate, well-graded—aggregate having a particle- the mixing of either concrete or mortar. (See also air en- size distribution that produces maximum density, that training and air, entrained.) is, minimum void space. air lift—equipment whereby slurry or dry powder is lifted aggregate blending—the process of intermixing two or through pipes by means of compressed air. more aggregates to produce a different set of properties, air meter—see meter, air. generally, but not exclusively, to improve grading. air-permeability test—see test, air-permeability and test, aggregate-cement ratio—see ratio, aggregate-cement. Blaine. aggregate gradation—see grading (preferred term). air ring—see ring, air.

CEMENT AND CONCRETE TERMINOLOGY 116R-3 air air separator—see separator, air. to the building frame; and in slabs on grade or walls, to air void—see void, air. fasten to rock or adjacent structures to prevent movement air-water jet—see jet, air-water. of the slab or wall with respect to the foundation, adjacent akermanite—a mineral of the melilite group, Ca2MgSi2O7. structure, or rock. (See also anchor, form.) (See also gehlenite, melilite, and merwinite.) anchor, form—device used to secure formwork to previous- alabaster—a compact, crystalline, weakly textured form of ly placed concrete of adequate strength; the device is nor- practically pure gypsum. mally embedded in the concrete during placement. alignment wire—see wire, ground (preferred term). anchor bolt—see bolt, anchor. alite—a name used to identify tricalcium silicate, including anchorage—in post-tensioning, a device used to anchor the small amounts of MgO, Al2O3, Fe2O3, and other oxides; tendon to the concrete member; in pretensioning, a device a principal constituent of portland-cement clinker. (See used to maintain the elongation of a tendon during the also belite, celite, and felite.) time interval between stressing and release; in precast- alkali—salts of alkali metals, principally sodium and potas- concrete construction, the devices for attaching precast sium; specifically, sodium and potassium occurring in units to the building frame; and in slab or wall construc- constituents of concrete and mortar, usually expressed in tion, the device used to anchor the slab or wall to the foun- chemical analyses as the oxides Na2O and K2O. (See also dation, rock, or adjacent structure. cement, low-alkali.) anchorage, dead-end—the anchorage at that end of a alkali-aggregate reaction—see reaction, alkali-aggregate. tendon that is opposite the jacking end. alkali-carbonate rock reaction—see reaction, alkali-car- anchorage, end— bonate rock. 1. length of reinforcement, mechanical anchor, hook, or alkali reactivity (of aggregate)—see reactivity (of aggre- combination thereof, beyond the point of nominal gate), alkali. zero stress in the reinforcement of cast-in-place con- alkali-silica reaction—see reaction, alkali-silicate. crete; and alkyl aryl sulfonate—synthetic detergent used to entrain air 2. mechanical device for transmitting prestressing in hydraulic cement mixtures. force to the concrete in a post-tensioned member. allowable bearing capacity—the maximum pressure to (See also anchorage.) which a soil or other material should be subjected to guard anchorage, mechanical—any mechanical device capa- against shear failure or excessive settlement. ble of developing the strength of the reinforcement allowable load—see load, service dead and load, service without damage to the concrete. live. anchorage, threaded—an anchorage device that is pro- allowable stress—see stress, allowable. vided with threads to facilitate attaching the jacking alternate-lane construction—see construction, alternate- device and to effect the anchorage. lane. anchorage, wedge—a device for anchoring a tendon by alumina—aluminum oxide (Al2O3). wedging. aluminate cement—see cement, calcium-aluminate. anchorage bond stress—see stress, anchorage bond. aluminate concrete—see concrete, aluminate. anchorage deformation—see deformation, anchorage or aluminous cement—see cement, calcium-aluminate. slip. amount of mixing—the extent of mixer action employed in anchorage device—see anchorage (preferred term). combining the ingredients for either concrete or mortar; in anchorage loss—see deformation, anchorage. the case of stationary mixers, the mixing time; and in the anchorage slip—see deformation, anchorage or slip. case of truck mixers, the number of revolutions of the anchorage zone—see zone, anchorage. drum at mixing speed after the intermingling of the ce- angle float—see float, angle. ment with water and aggregates. (See also mixing time.) angle of repose—the angle between the horizontal and the amplitude—the maximum displacement from the mean po- natural slope of loose material below which the material sition in connection with vibration. will not slide. analysis, dynamic—analysis of stresses in framing as func- angular aggregate—see aggregate, angular. tions of displacement under transient loading. anhydrite—a mineral, anhydrous calcium sulfate (CaSO4); analysis, mechanical—the process of determining particle- gypsum from which the water of crystallization has been size distribution of an aggregate. (See also analysis, removed, usually by heating above 325 F (160 C); natural sieve.) anhydrite is less reactive than that obtained by calcination analysis, sieve—particle-size distribution; usually expressed of gypsum. as the mass percentage retained upon each of a series of anhydrous calcium chloride—see calcium chloride, anhy- standard sieves of decreasing size and the percentage drous. passed by the sieve of finest size. (See also grading.) apparent specific gravity—see specific gravity, absolute. anchor—in prestressed concrete, to lock the stressed tendon architect-engineer or engineer-architect—the architect, in position so that it will retain its stressed condition; in engineer, architectural firm, engineering firm, or archi- precast-concrete construction, to attach the precast units tectural and engineering firm issuing project drawings

116R-4 ACI COMMITTEE REPORT bar

and specifications, or administering the work under con- back plastering—plaster applied to one face of a lath sys- tract specifications and drawings, or both. tem following application and subsequent hardening of architectural concrete—see concrete, architectural. plaster applied to the opposite face. (See also parge.) arc spectrography—spectrographic identification of ele- back stay—see brace (preferred term). ments in a sample of material heated to volatilization in backshores—shores placed snugly under a concrete slab or an electric arc or spark. structural member after the original formwork and shores area of steel—the cross-sectional area of the steel reinforce- have been removed from a small area without allowing ment. (See also effective area of reinforcement.) the entire slab or member to deflect or support its own arenaceous—composed primarily of sand; sandy. mass or existing construction loads. argillaceous—composed primarily of clay or shale; clayey. bacterial corrosion—see corrosion, bacterial. arris—the ridge formed by the meeting of two surfaces. bag (of cement; also sack)—a quantity of portland cement: arrissing tool—see tool, arrissing. 94 lb (43 kg) in the U.S.; for other kinds of cement, quan- artificial pozzolan—see pozzolan, artificial. tity indicated on the bag. asbestos-cement products—products manufactured from balanced load—see load, balanced. rigid material composed essentially of asbestos fiber and balanced moment—moment capacity at simultaneous portland cement. crushing of concrete and yielding of tension steel. ashlar—see masonry, ashlar. balanced reinforcement—an amount and distribution of re- ashlar, patterned—see masonry, ashlar. inforcement in a flexural member such that in working- ashlar masonry—see masonry, ashlar. stress design the allowable tensile stress in the steel and ashlar, random—see masonry, ashlar. the allowable compressive stress in the concrete are at- asphalt—a dark brown to black cementitious material in tained simultaneously; or such that in strength design, the which the predominating constituents are bitumens that tensile reinforcement reaches its specified yield strength occur in nature or are obtained in petroleum processing. simultaneously with the concrete in compression reach- asphalt cement—see cement, asphalt. ing its assumed ultimate strain of 0.003. asphaltic concrete—see concrete, asphaltic. ball mill—see mill, ball. atmospheric-pressure steam curing—see curing, atmo- ball test—see test, ball. spheric-pressure steam. band iron—thin metal strap used as a form tie, hanger, etc. Atterberg limits—see limits, Atterberg. bar—an element, normally composed of steel, with a nominal- Atterberg test—see test, Atterberg. ly uniform cross-sectional area used to reinforce concrete. autoclave—a pressure vessel in which an environment of bar, coated—a bar on which a coating has been applied, steam at high pressure may be produced; used in the cur- usually to increase resistance to corrosion. ing of concrete products and in the testing of hydraulic bar, deformed—a reinforcing bar with a manufactured cement. pattern of surface ridges intended to reduce slip and in- autoclave curing—see curing, autoclave. crease pullout resistance of bars embedded in concrete. autoclave cycle—see cycle, autoclave. bar, epoxy-coated—a reinforcing bar coated by an epoxy- autoclaved—see curing, autoclave. resin system, usually to increase resistance to corrosion. autoclaving—see curing, autoclave. bar, high-bond—see bar, deformed (preferred term). autogenous healing—see healing, autogenous. autogenous length change—see length change, autogenous. bar, plain—a reinforcing bar without surface deforma- autogenous volume change—see volume change, autoge- tions, or one having deformations that do not conform nous. to the applicable requirements. automatic batcher—see batcher. bar, reinforcement—see reinforcement. auxiliary reinforcement—see reinforcement, auxiliary. bar, standard hooked—a reinforcing bar with the end average bond stress—see bond stress, average. bent into a hook to provide anchorage. average compressive strength—see compressive strength, bar, tie—bar at right angles to, and tied to reinforcement average. to keep it in place. axis, neutral—a line in the plane of a structural member bar bender—a tradesman who cuts and bends steel rein- subject to bending where the longitudinal stress is zero. forcement; or a machine for bending steel reinforce- axle load—see load, axle. ment. axle steel—see steel, axle. bar-end check—a check of the ends of reinforcing bars to axle-steel reinforcement—see reinforcement, axle-steel. determine whether they fit the devices intended for con- necting the bars. (See also mechanical connection.) B bar mat—an assembly of steel reinforcement composed of two or more layers of bars placed at angles to each other b/bo—see factor, coarse-aggregate (preferred term). and secured together either by welding or tying. bacillus, cement—see ettringite (preferred term). bar schedule—a list of the reinforcement, showing the backfill concrete—see concrete, backfill. shape, number, size, and dimensions of every different el- back form—see form, top (preferred term). ement required for a structure or a portion of a structure.

CEMENT AND CONCRETE TERMINOLOGY 116R-5 bar bar spacing—the distance between parallel reinforcing bars, into the mixer the ingredients for a quantity of either con- measured center to center of the bars perpendicular to crete or mortar. their longitudinal axes. batch, trial—a batch of concrete prepared to establish or bar support—hardware used to support or hold reinforcing check proportions of the constituents. bars in proper position to prevent displacement before and batch box—container of known volume used for measuring during concreting. (See also bat; bolster, slab; chair.) constituents of a batch of either concrete or mortar in barite—a mineral, barium sulfate (BaSO4), used in either proper proportions. pure or impure form as concrete aggregate primarily for batch mixer—see mixer, batch. the construction of high-density radiation shielding con- batch plant—an installation for batching or for batching and crete; designated “barytes” in the UK. mixing concrete materials. barrage—a low dam erected to control the level of a stream. batch weights—the quantities of the various ingredients barrel (of cement)—a quantity of portland cement: 376 lb (4 (cement, water, the several sizes of aggregate, and admix- bags) in the U.S. (obsolete); also wood or metal container tures if used) that compose a batch of concrete. formerly used for shipping cement. batched water—the mixing water added by a batcher to a barrel-vault roof—see roof, barrel-vault. cementitious mixture either before or during the initial barrier, moisture—a vapor barrier. stages of mixing (also called batch water). barrier, vapor—membranes located under concrete floor batcher—a device for measuring ingredients for a batch of slabs that are placed on grade to retard transmission of concrete. water vapor from the subgrade. batcher, automatic—a batcher equipped with gates or bars, bundled—a group of not more than four parallel rein- valves that, when actuated by a single starter switch, forcing bars in contact with each other, usually tied together. will open automatically at the start of the weighing op- bars, stem—bars used in the wall section of a cantilevered eration of each material, and will close automatically retaining wall or in the webs of a box; when a cantilevered when the designated quantity of each material has been retaining wall and its footing are considered as an integral reached, interlocked in such a manner that: a) the unit, the wall is often referred to as the stem of the unit. charging mechanism cannot be opened until the scale base—a subfloor slab or “working mat,” either previously has returned to zero; b) the charging mechanism cannot placed and hardened or freshly placed, on which floor top- be opened if the discharge mechanism is open; c) the ping is placed in a later operation; also the underlying discharge mechanism cannot be opened if the charging stratum on which a concrete slab, such as a pavement, is mechanism is open; d) the discharge mechanism cannot placed. (See also mud slab and subbase.) be opened until the designated quantity has been base bead—see base screed (preferred term). reached within the allowable tolerance; and e) if differ- base coat—any plaster coat or coats applied before applica- ent kinds of aggregates or different kinds of cements tion of the finish coat. are measured cumulatively in a single batcher, inter- base course—a layer of specified select material of planned locked sequential controls are provided. thickness constructed on the subgrade or subbase of a batcher, manual—a batcher equipped with gates or pavement to serve one or more functions, such as distrib- valves that are operated manually, with or without sup- uting loads, providing drainage, or minimizing frost ac- plementary power (pneumatic, hydraulic, or electri- tion; also the lowest course of masonry in a wall or pier. cal), the accuracy of the weighing operation being base plate—a plate of metal or other material formerly dependent on the operator’s observation of the scale. placed under pavement joints and the adjacent slab ends batcher, semiautomatic—a batcher equipped with gates to prevent the infiltration of soil and moisture from the or valves that are separately opened manually to allow sides or bottom of the joint opening; also a steel plate used the material to be weighed but that are closed automat- to distribute vertical loads, as for bridge beams, building ically when the designated quantity of each material columns, or machinery. has been reached. base screed—a preformed metal screed with perforated or batching, cumulative—measuring more than one ingredi- expanded flanges to provide a guide for thickness and ent of a batch in the same container by bringing the batch- planeness of plaster and to provide a separation between er scale into balance at successive total weights as each plaster and other materials. ingredient is accumulated in the container. basic creep—see creep, basic. batten (also batten strip)—a narrow strip of wood placed basket—see load-transfer assembly (preferred term). over the vertical joint of sheathing or paneling; also used 


## % %(   +",⋅- , to hold several boards together. (See also cleat.) "   
 

  batter—inclination from the vertical or horizontal. bat—a broken brick sometimes used to support reinforce- batter boards—pairs of horizontal boards nailed to wooden ment. (See also bar support.) stakes adjoining an excavation; used as a guide to eleva- batch—n. quantity of either concrete or mortar mixed at one tions and to outline the building. time; v. to weigh or volumetrically measure and introduce batter pile—see pile, batter.

116R-6 ACI COMMITTEE REPORT blast bauxite—a rock composed principally of hydrous alumi-  
 %    ( (( #  %  num oxides; the principal ore of aluminum and a raw ma- ( &# # . ). ) )  %  & terial for manufacture of calcium-aluminate cement. ## %  # +,⋅" , " 
 ! !  bay—the space, in plan, between the centerlines of adjacent   piers, mullions, or columns; a small, well-defined area of bench—see pretensioning bed. concrete placed at one time in the course of placing large bending moment—see moment, bending. areas, such as floors, pavements, or runways. bending moment diagram—a graphical representation of beam—a structural member subjected to primarily flexure, the variation of bending moment along the length of the but also to axial load; and, the graduated horizontal bar of member for a given stationary system of loads. a weighing scale on which the balancing poises ride. (See beneficiation—improvement of the chemical or physical also beam, spandrel; girder; girt; joist; ledger; purlin; properties of a raw material or intermediate product by and stringer.) the removal or modification of undesirable components beam, double-tee—a precast concrete member com- or impurities. posed of two stems and a combined top flange, com- bent, pile—two or more piles driven in a row transverse to monly used as a beam but also used vertically in the long dimension of the structure and fastened together exterior walls. by capping and (sometimes) bracing. beam, drop-in—a precast element simply supported on bent bar—a reinforcing bar bent to a prescribed shape. (See adjacent cantilevered elements. also hook; bar, hooked; stirrup; and tie.) beam, edge—a stiffening beam at the edge of a slab. bentonite—a clay composed principally of minerals of the beam, grade—a reinforced concrete beam, usually at montmorillonoid group, characterized by high adsorption ground level, that strengthens or stiffens the founda- and very large volume change with wetting or drying. tion or supports overlying construction. Berliner—a type of terrazzo topping using small and large beam, simple—a beam without rotational restraint or pieces of marble paving, usually with a standard terrazzo continuity at its supports; also known as a simply sup- matrix between pieces, also called Palladiana. ported beam. billet steel—see steel, billet. beam, slender—a beam that, if loaded to failure without binder—a cementing material, either a hydrated cement or lateral bracing of the compression flange, would fail reaction products of cement or lime and reactive siliceous by buckling rather than in flexure. material, the kind of cement and curing conditions gov- beam, spandrel—a beam in the perimeter of a building, erning the characteristics of the product formed; also ma- spanning between columns and usually supporting a terials such as asphalt, resins, and other materials forming floor or roof. the matrix of concretes, mortars, and sanded grouts. beam-and-slab floor (roof)—a reinforced concrete system biological shielding—shielding provided to attenuate or ab- in which a slab is supported by and is often monolithic sorb nuclear radiation, such as neutron, proton, alpha and with reinforced-concrete beams. beta particles, and gamma radiation; the shielding is pro- beam bottom—soffit or bottom form for a beam. vided mainly by the density of the concrete, except that in beam-column—a structural member subjected to axial load the case of neutrons the attenuation is achieved by com- and flexure forces but primarily axial load. pounds of some of the lighter elements (for example, hy- beam form—a retainer or mold so erected as to give the drogen and boron). (See also concrete, shielding.) necessary shape, support, and finish to a concrete beam. bituminous cement—see cement, bituminous. beam form-clamp—any of various types of tying or fasten- Blaine apparatus—air-permeability apparatus for measur- ing units used to hold the sides of beam forms. ing the surface area of a finely ground cement, raw mate- beam hanger—a wire, strap, or other hardware device that rial, or other product. (See ASTM C 204.) supports formwork from structural members. Blaine fineness—the fineness of powdered materials such as beam pocket—opening left in a vertical member in which a cement and pozzolans, expressed as surface area per unit beam is to rest; also an opening in the column or girder mass usually in square meters per kilogram, determined by form where forms for an intersecting beam will be the Blaine apparatus. (See also surface, specific.) framed. Blaine test—see test, Blaine. beam saddle—see beam hanger (preferred term). blanket, curing—a covering of sacks, matting, burlap, beam side—vertical or sloping side of a beam. straw, waterproof paper, or other suitable material placed beam test—a method of measuring the flexural strength over freshly finished concrete. (See also burlap.) (modulus of rupture) of concrete by testing a standard un- blast-furnace slag—the nonmetallic product consisting reinforced beam. essentially of silicates and aluminosilicates of calcium bearing capacity—see allowable bearing capacity. and other bases that is developed in a molten condition bearing stratum—the soil or rock stratum on which a con- simultaneously with iron in a blast furnace. crete footing or mat bears or that carries the load trans- 1. air-cooled blast-furnace slag is the material resulting ferred to it by a concrete pile, caisson, or similar deep from solidification of molten blast-furnace slag under foundation unit. atmospheric conditions; subsequent cooling may be

CEMENT AND CONCRETE TERMINOLOGY 116R-7 bleed

accelerated by application of water to the solidified joint between them will accommodate; typically occurs surface; only in unusually hot weather where joints have become 2. expanded blast-furnace slag is the low density, cellular filled with incompressible material; often results in cracks material obtained by controlled processing of molten on both sides of the joint and parallel to it. blast-furnace slag with water, or water and other board butt joint—construction joint in shotcrete formed by agents, such as steam, compressed air, or both; sloping the sprayed surface to a 1 in. (25 mm) board laid 3. granulated blast-furnace slag is the glassy, granular flat. material formed when molten blast-furnace slag is rap- bolster, slab—continuous wire bar support used to support idly chilled, as by immersion in water; and bars in the bottom of slabs; top wire is corrugated at 1 in. 4. ground granulated blast-furnace slag is granulated centers to hold bars in position. (See also bar support.) blast-furnace slag that has been finely ground and is a bolt, anchor—a metal bolt or stud, headed or threaded, ei- hydraulic cement. ther cast in place, grouted in place, or drilled into finished bleed—to undergo bleeding. (See bleeding.) concrete, used to hold various structural members or em- bleeding—the autogenous flow of mixing water within, or bedments in the concrete, and to resist shear, tension, and its emergence from, newly placed concrete or mortar; vibration loadings from various sources, such as wind and caused by the settlement of the solid materials within the machine vibration; also known as a hold-down bolt or a mass; also called water gain. foundation bolt. bleeding capacity—the ratio of volume of water released by bolt, foundation—see bolt, anchor. bleeding to the volume of paste or mortar. bolt, hold-down—anchor bolt provided near the ends of bleeding rate—the rate at which water is released from a shear walls for transferring boundary-member loads from paste or mortar by bleeding. the shear wall to the foundation. (See also bolt, anchor.) blemish—any superficial defect that causes visible variation bolt, she—a type of form tie and spreader bolt in which the from a consistently smooth and uniformly colored surface end fastenings are threaded into the end of the bolt, thus of hardened concrete. (See also bug holes; efflorescence; eliminating cones and reducing the size of holes left in the honeycomb; joint, lift; laitance; popout; rock pocket; concrete surface. and sand streak.) bolt sleeve—a tube surrounding a bolt in a concrete wall to blended cement—see cement, blended. prevent concrete from adhering to the bolt and acting as a blinding—the application of a layer of lean concrete or other spreader for the formwork. suitable material to reduce surface voids or to provide a bond— clean, dry working surface; also the filling or plugging of 1. adhesion of concrete or mortar to reinforcement or other the openings in a screen or sieve by the material being surfaces against which it is placed, including friction separated. (See concrete, lean.) due to shrinkage and longitudinal shear in the concrete blistering—the irregular raising of a thin layer at the surface engaged by the bar deformations; of placed mortar or concrete during or soon after comple- tion of the finishing operation, or in the case of pipe after 2. adhesion of cement paste to aggregate; spinning; also bulging of the finish plaster coat as it sepa- 3. adhesion or cohesion between plaster coats or between rates and draws away from the base coat. plaster and a substrate produced by adhesive or cohesive bloated—swollen, as in certain lightweight aggregates as a properties of plaster or supplemental materials; and result of processing. 4. patterns formed by the exposed faces of masonry units, block, concrete—a concrete masonry unit, usually contain- for example, running bond or flemish bond. ing hollow cores. bond, ceramic—the development of fired strength as a block, end—an enlarged end section of a member intended result of thermochemical reactions between materials to reduce anchorage stresses to allowable values and pro- exposed to temperatures approaching the fusion point vide space needed for post-tensioning anchorages. of the mixture such as that which may occur, under block, wood—a solid piece of wood used in concrete form- these conditions, between calcium-aluminate cement work to fill space or prevent movement of the formwork. and a refractory aggregate. block beam—a flexural member composed of individual bond, chemical—bond between materials that is the result blocks that are joined together by prestressing. (See also of cohesion and adhesion developed by chemical reac- member, segmental.) tion. blockout—a space within a concrete structure under con- bond, flexural stress—in structural-concrete members, struction in which fresh concrete is not to be placed, the stress between the concrete and the reinforcing el- called core in the UK. ement that results from the application of external blowdown period—time taken to reduce pressure in an au- load. toclave from maximum to atmospheric. bond, mechanical— blowholes—see surface air voids (preferred term). 1. in general concrete construction, the physical inter- blowup—the raising of two concrete slabs off the subgrade lock between cement paste and aggregate, or be- where they meet as a result of greater expansion than the tween concrete and reinforcement (specifically, the

116R-8 ACI COMMITTEE REPORT bulk

sliding resistance, not the adhesive resistance, of an   
        ## %  # embedded bar); and  +,⋅" , ##%  %"#)-   2. in plastering, the physical keying of a plaster coat /       /  ( 0%#. "#       to: a) another; b) to the plaster base by means of        #  plaster keys to the lath; or c) through interlock with breeze—usually clinker; also fine, divided material from adjacent plaster casts created by means of scratch- coke production. ing or cross raking. brick, calcium-silicate—a concrete product made principally bond, transfer—in pretensioning, the bond stress result- from sand and lime that is hardened by autoclave curing. ing from the transfer of stress from the tendon to the brick, concrete—solid concrete masonry units of relatively concrete. small prescribed dimensions. bond area—the nominal area of interface between two ele- brick, rubbing—a silicon-carbide brick used to smooth and ments across which adhesion develops or may develop, remove irregularities from surfaces of hardened concrete. as between cement paste and aggregate. brick, sand-lime—see brick, calcium-silicate (preferred bond breaker—a material used to prevent adhesion of new- term). ly placed concrete to the substrate. (See also oil, form brick seat—ledge on wall or footing to support a course of and agent, release.) masonry. bond length—see length, development (preferred term). bridge deck—see deck, bridge. bond plaster—a specially formulated gypsum plaster de- briquette (also briquet)—a molded specimen of mortar signed as first-coat application over monolithic concrete. with enlarged extremities and reduced center having a bond prevention—measures taken to prevent adhesion of cross section of definite area, used for measurement of concrete or mortar to surfaces against which it is placed. tensile strength. bond strength—see strength, bond. broadcast—to toss granular material, such as sand, over a bond stress—see stress, bond. horizontal surface so that a thin, uniform layer is ob- bond stress, average—the force in a bar divided by the tained. product of the perimeter and the development length of broom finish—see finish, broom. the bar. brown coat—see coat, brown. bond stress, development—see stress, anchorage bond brown out—to complete application of base coat plaster. (preferred term). brown oxide—see oxide, brown. brownmillerite—a ternary compound originally regarded bonded hollow-wall masonry—see masonry, bonded hol- as 4CaO⋅Al O⋅Fe O (C AF) occurring in portland and low-wall. 2 2 3 4 calcium-aluminate cement; now used to refer to a series bonded member—a prestressed-concrete member in which of solid solutions between 2CaO⋅Fe O (C F) and the tendons are bonded to the concrete either directly or 2 3 2 2CaO⋅Al O (C A). through grouting. 2 3 2 brucite—a mineral having the composition magnesium hy- bonded post-tensioning—see post-tensioning, bonded. droxide, Mg(OH) , and a specific crystal structure. bonded tendon—see tendon, bonded. 2 brushed surface—see surface, brushed. bonder—a masonry unit that ties two or more wythes buck—framing around an opening in a wall; a door buck en- (leaves) of a wall together by overlapping. (See also closes the opening in which a door is placed. header and wythe [leaf].) buckling—failure by lateral or torsional instability of a bonding agent—see agent, bonding. structural member, occurring with stresses below the bonding layer—see layer, bonding. yield or ultimate values. bored pile—see pier, drilled. bug holes—see surface air voids (preferred term). boring—the removal by drilling of rock; a sample of soil or buggy—a two-wheeled hand or motor-driven cart, usually concrete for tests. rubber-tired, for transporting small quantities of concrete boron frits—clear, colorless, synthetic glass produced by from hoppers or mixers to forms; sometimes called a con- fusion and quenching, containing boron. (See also con- crete cart. crete, boron-loaded.) building official—the official charged with administration boron-loaded concrete—see concrete, boron-loaded. and enforcement of the applicable building code, the duly box out—to form an opening in concrete by a box-like form. authorized representative of the official. brace—a structural member used to provide lateral support build-up—spraying of shotcrete in successive layers to form for another member, generally for the purpose of ensur- a thicker mass; also the accumulation of residual hard- ing stability or resisting lateral loads. ened concrete in a mixer. bracing—see brace (preferred term). bulk cement—see cement, bulk. bracket—an overhanging member projecting from a wall or bulk density—see density, bulk. other body to support weight acting outside the wall, or a bulk loading—see loading, bulk. similar piece to strengthen an angle. (See also corbel.) bulk modulus—see modulus, bulk. breccia—rock composed of angular fragments of older rock bulk specific gravity—see specific gravity, absolute and cemented together. density, bulk.

CEMENT AND CONCRETE TERMINOLOGY 116R-9 bulk bulk specific gravity (saturated-surface dry)—see specific calcium—a silver-white metallic element of the alkaline- gravity, absolute. earth group occurring naturally only in combination with bulkhead—a partition in formwork blocking fresh concrete other elements. from a section of the form, or a partition closing a section calcium-aluminate cement—see cement, calcium-alu- of the form, such as at a construction joint; a partition in a minate. storage tank or bin, as for cement or aggregate. calcium chloride—a crystalline solid, CaCl2; in various bulking—increase in the volume occupied by a quantity of technical grades, used as a drying agent, as an accelerator sand in a moist condition over the volume of the same of concrete, as a deicing chemical, and for other purposes. quantity dry or completely inundated. (See also admixture, accelerating.) bulking curve—graph of change in volume of a quantity of calcium chloride, anyhdrous (CaCl2)—a solid, usually sand due to change in moisture content. 94% calcium chloride, typically in pellet form. bulking factor—see factor, bulking. calcium chloride, hydrous (CaCl2·2H2O)—a solid, usually bull float—see float, bull. 77% calcium chloride, in flake form. bundled bars—see bars, bundled. calcium chloride solution—an aqueous solution of calcium burlap—a coarse fabric of jute, hemp, or less commonly, chloride (usually at a specified concentration so that a flax, for use as a water-retaining covering in curing con- given amount can be gauged to provide a specific concen- crete surfaces; also called Hessian. tration) usually expressed as a percent calcium chloride bush-hammer—a hammer having a serrated face, as rows of by mass of portland cement. pyramidal points, used to roughen or dress a surface; to fin- calcium hydroxide—see lime, hydrated. ish a concrete surface by application of a bush-hammer. calcium stearate—Ca(C18H35O2)2, commonly marketed in bush-hammer finish—see finish, bush-hammer. powder form, insoluble in water, used as a water repellent butt joint—see joint, butt. admixture in concrete. butter—to spread mortar on a masonry unit with a trowel; calcium-silicate brick—see brick, calcium-silicate. also the process by which the interior of a concrete mixer, calcium-silicate hydrate—see hydrate, calcium-silicate. transportation unit, or other item coming in contact with caliche—gravel, sand, and desert debris cemented by calci- fresh concrete is provided with a mortar coating so that um carbonate or other salts. fresh concrete coming in contact with it will not be depleted California bearing ratio (CBR)—the ratio of the force per of mortar. unit area required to penetrate a soil mass with a 3 in.2 buttress—a projecting structure to support either a wall or a (1940 mm2) circular piston at the rate of 0.05 in. (1.3 mm) building. per min to the force required for corresponding penetra- butyl stearate—a colorless, oily, and practically odorless tion of a standard material; the ratio is usually determined material (C17 H35 COOC4 H9) used as an admixture for at 0.1 in. (2.5 mm) penetration. concrete to provide dampproofing. calorimeter—an instrument for measuring heat exchange during a chemical reaction, such as the quantity of heat lib- C erated by the combustion of a fuel or hydration of a cement. camber—a deflection that is intentionally built into a struc- cabinet, moist—an upright and compartmented case having tural element or form to improve appearance or to nullify doors and shelves of moderate dimensions for storing and the deflection of the element under the effects of loads, curing small test specimens of cement paste, mortar, and shrinkage, and creep. concrete in an atmosphere of approximately 73 F (23 C) cant strip—see strip, chamfer (preferred term). and at least 95% relative humidity. (See also moist cap—a smooth plane surface of suitable material bonded to room.) the bearing surfaces of test specimens to distribute the cable—see tendon (preferred term). load during strength testing. cage—a rigid assembly of reinforcement ready for placing in cap cables—short cables (tendons) introduced to prestress position. the zone of negative moment only. caisson—part of a foundation, a watertight chamber used in capacity—a measure of the rated volume of a particular con- construction underwater, or a hollow floating box used as crete mixer or agitator, usually limited by specifications a floodgate for a dock or basin. to a maximum percentage of total gross volume; also the caisson pile—see pile, caisson. output of concrete, aggregate, or other product per unit of calcareous—containing calcium carbonate or, less generally, time (as plant capacity or screen capacity); also load-car- containing the element calcium. rying limit of a structure. calcine—to alter composition or physical state by heating capacity-reduction factor—see strength-reduction factor below the temperature of fusion. (preferred term). calcite—a mineral having the composition calcium carbon- capillarity—the movement of a liquid in the interstices of ate (CaCO3) and a specific crystal structure; the principal concrete, soil, or other finely porous material due to sur- constituent of limestone, chalk, and marble; a major con- face tension. (See also flow, capillary.) stituent in the manufacture of portland cement. capillary flow—see flow, capillary.

116R-10 ACI COMMITTEE REPORT cement capillary space—see space, capillary. cement, air-entraining hydraulic—hydraulic cement cap, pile— containing an air-entraining agent in sufficient amount 1. a structural member that is placed on top of a group of to entrain air in mortar within specified limits. piles and used to transmit loads from the structure cement, aluminous—see cement, calcium-aluminate through the pile group into the soil; the piles may be (preferred term). connected to the cap with reinforcement to resist uplift cement, asphalt—asphalt that is refined to meet speci- or with reinforcement to resist moment so as to form a fications for use in the manufacture of bituminous bent; also known as a rider cap or girder; also a mason- pavements. ry, timber, or concrete footing resting on a group of cement, bituminous—a black solid, semisolid, or liquid piles; and substance at natural air temperatures and appreciably 2. a metal cap or helmet temporarily fitted over the head soluble only in carbon disulfide or some volatile liquid of a precast pile to protect it during driving; some form hydrocarbon, being composed of mixed indeterminate of shock-absorbing material is often incorporated. hydrocarbons mined from natural deposits, produced cap, rider—see cap, pile (preferred term). as a residue in the distillation of petroleum, or obtained carbon black—a finely divided form of carbon produced by by the destructive distillation of coal or wood. the combustion or partial decomposition of hydrocarbon, cement, blended—a hydraulic cement consisting essen- used as an admixture to color concrete. tially of an intimate and uniform blend of granulated carbonation—reaction between carbon dioxide and a hy- blast-furnace slag and hydrated lime; or an intimate droxide or oxide to form a carbonate, especially in ce- and uniform blend of portland cement and granulated ment paste, mortar, or concrete; the reaction with calcium blast-furnace slag, portland cement and pozzolan, or compounds to produce calcium carbonate. portland blast-furnace slag cement and pozzolan, pro- carbonation shrinkage—see shrinkage, carbonation. duced by intergrinding portland cement clinker with carriageway—in the UK, a term used in the same meaning the other materials or by blending portland cement as the word “road” in the U.S. with the other materials, or a combination of inter- cast-in-place—referring to a cementitious mixture that is grinding and blending. deposited in the place where it is required to harden as cement, bulk—cement that is transported and delivered part of the structure, as opposed to precast concrete. in bulk (usually in specially constructed vehicles) in- cast-in-place concrete—see concrete, cast-in-place. stead of in bags. cast-in-place pile—see pile, cast-in-place. cement, calcium-aluminate—the product obtained by cast-in-situ—see cast-in-place (preferred term). pulverizing clinker consisting essentially of hydraulic cast stone—see stone, cast. calcium aluminates resulting from fusing or sintering a castable refractory—see refractory, castable. suitably proportioned mixture of aluminous and calcar- catalyst—a substance that accelerates a chemical reaction eous materials; called high-alumina cement in the UK. and enables it to proceed under conditions more mild than cement, chemically prestressing—a type of expansive otherwise required and which is not, itself, permanently cement containing a higher percentage of expansive changed by the reaction. (See also catalyst, negative.) component than a shrinkage-compensating cement, catalyst, negative—a substance that slows a chemical reaction when used in concretes with adequate internal or ex- and which, itself, does not enter into the reaction; inhibitor. ternal restraint, that will expand sufficiently due to catface—blemish or rough depression in the finish plaster chemical reactions within the matrix, to develop the coat caused by variations in the base coat thickness. stresses necessary for prestressing the concrete. (See cathead—a notched wedge placed between two formwork also cement, expansive.) members meeting at an oblique angle; a spindle on a cement, expanding—see cement, expansive (preferred hoist; the large, round retention nut used on she bolts. term). cathodic protection—the form of corrosion protection cement, expansive—a cement that, when mixed with wa- wherein one metal is caused to corrode in preference to ter, produces a paste that, after setting, increases in another, thereby protecting the latter from corrosion. volume to a significantly greater degree than does catwalk—a narrow elevated walkway. portland-cement paste; used to compensate for volume caulk—to place a material in a crack or joint with the intent decrease due to shrinkage or to induce tensile stress in of retarding entry of dirt or water. (See also joint filler or reinforcement (post-tensioning). sealant, joint.) *cement, expansive, Type K—a mixture of portland ce- cavitation damage—see damage, cavitation. ment, anhydrous tetracalcium trialuminate sulfate celite—a name used to identify the calcium aluminoferrite (C4A3S), calcium sulfate (CaSO4), and lime (CaO); constituent of portland cement. (See also alite; belite; fe- the C4A3S is a constituent of a separately burned clin- lite; and brownmillerite.) ker that is interground with portland cement or alter- cellular concrete—see concrete, cellular. nately, it may be formed simultaneously with the cellular construction—see construction, cellular. portland-cement clinker compounds during the burn- cement—see cement, hydraulic. ing process;

CEMENT AND CONCRETE TERMINOLOGY 116R-11 cement

2. cement, expansive, Type M—interground or blend- low the sintering point and then grinding to a fine ed mixtures of portland cement, calcium-aluminate powder. cement, and calcium sulfate suitably proportioned; cement, nonstaining—a masonry cement that contains and not more than a stipulated amount of water-soluble al- 3. cement, expansive, Type S—a portland cement con- kali as measured by a stipulated test method. taining a high computed tricalcium aluminate (C3A) cement, normal—general purpose portland cement, re- content and an amount of calcium sulfate above the ferred to in the U.S. as Type I. usual amount found in portland cement cement, oil-well—hydraulic cement suitable for use un- cement, high-alumina—see cement, calcium-alumi- der high pressure and temperature in sealing water and nate (preferred term). gas pockets, and setting casing during the drilling and cement, high-early-strength—portland cement charac- repair of wells; often contains retarders to meet the re- terized by attaining a given level of strength in mortar quirements of use. or concrete earlier than does normal portland cement; cement, ordinary portland—the term used in the UK referred to in the U.S. as Type III. and elsewhere to designate the equivalent of American cement, high-fineness—a hydraulic cement of substan- normal portland cement or Type I cement; commonly tially higher specific surface and substantially smaller abbreviated OPC. mean particle diameter than typical for products of cement, plastic—a special product manufactured for similar composition, produced by additional grinding plaster and stucco application. or by separation by particle size. cement, portland—a hydraulic cement produced by pul- cement, hot—newly manufactured cement that has not verizing portland-cement clinker, usually in combina- had an opportunity to cool after burning and grinding tion with calcium sulfate. of the component materials. cement, portland blast-furnace slag—a hydraulic ce- cement, hydraulic—a cement that sets and hardens by ment consisting of an intimately interground mixture chemical interaction with water and is capable of doing of portland-cement clinker and granulated blast-fur- so underwater, for example, portland cement and ground nace slag or an intimate and uniform blend of portland granulated blast-furnace slag are hydraulic cements. cement and fine granulated blast-furnace slag in which cement, hydrophobic—unhydrated cement treated so as the amount of the slag constituent is within specified to have reduced tendency to take up moisture. limits. cement, Keene’s—a cement composed of finely ground, anhydrous, calcined gypsum, the set of which is accel- cement, portland-pozzolan—a hydraulic cement con- erated by the addition of other materials. sisting of an intimate and uniform blend of portland cement, low-alkali—a portland cement that contains a cement or portland blast-furnace slag cement and fine relatively small amount of sodium or potassium or pozzolan produced by intergrinding portland-cement both; in the U.S., a portland cement containing not clinker and pozzolan, by blending portland cement or portland blast-furnace slag cement and finely divided more than 0.60% Na2O equivalent, that is, percent × pozzolan, or a combination of intergrinding and blend- Na2O + 0.658 percent K2O. cement, low-heat—a portland cement for use when a low ing, in which the pozzolan constituent is within speci- heat of hydration is desired, referred to in U.S. as Type fied limits. IV. cement, regulated-set—a hydraulic cement containing cement, masonry—a hydraulic cement for use in mortars fluorine-substituted calcium aluminate, capable of for masonry construction; contains one or more of the very rapid setting. following materials: portland cement, portland blast- cement, Roman—a misnomer for a hydraulic cement furnace slag cement, portland-pozzolan cement, natu- made by calcining a natural mixture of calcium car- ral cement, slag cement or hydraulic lime; and in addi- bonate and clay, such as argillaceous limestone, to a tion usually contains one or more materials, such as temperature below that required to sinter the material hydrated lime, limestone, chalk, calcareous shell, talc, but high enough to decompose the calcium carbonate, slag, or clay in finely ground condition. followed by grinding; so named because its brownish cement, moderate sulfate-resisting—a portland cement color resembles ancient Roman cements produced by for use when either moderate sulfate resistance or use of lime-pozzolan mixtures. moderate heat of hydration or both is desired, now re- cement, self-stressing—see cement, expansive. ferred to as Type II. cement, shrinkage-compensating—see cement, expan- cement, modified—a portland cement for use when ei- sive. ther moderate heat of hydration, moderate sulfate re- cement, slag—hydraulic cement consisting mostly of an sistance, or both, is desired, now referred to as Type II intimate and uniform blend of granulated blast-furnace (an obsolete term). slag and portland cement, hydrated lime, or both, in cement, natural—a hydraulic cement produced by cal- which the slag constituent is at least 10% by mass of cining an argillaceous limestone at a temperature be- the finished product.

116R-12 ACI COMMITTEE REPORT clay

cement, sticky—finished cement that develops low or central mixer—see mixer, central. zero flowability during or after storage in silos, or af- centrifugally cast concrete—see concrete, centrifugally ter transportation in bulk containers, hopper-bottom cast. cars, etc.; may be caused by: a) interlocking of parti- centrifugal process—see process, centrifugal. cles; b) mechanical compaction; c) electrostatic attrac- ceramic bond—see bond, ceramic. tion between particles. (See also set, warehouse.) chair—see bar support (preferred term), and bat. cement, sulfate-resistant—portland cement, low in tri- chalk—a soft limestone composed chiefly of the calcareous calcium aluminate, that reduces susceptibility of con- remains of marine organisms. crete to attack by dissolved sulfates in water or soils, designated Type V in the U.S. chalking—formation of a loose powder resulting from the disintegration of the surface of concrete or of applied cement, sulfoaluminate—see cement, expansive, coating, such as cement paint. Type K. cement, supersulfated—a hydraulic cement made by in- chamfer—either a beveled edge or corner formed in con- timately intergrinding a mixture of granulated blast- crete work by means of a chamfer strip. furnace slag, calcium sulfate, and a small amount of chamfer strip—see strip, chamfer. lime, portland cement, or portland cement clinker; so charge—to introduce, feed, or load materials into a concrete named because the equivalent content of sulfate ex- or mortar mixer, furnace, or other container or receptacle ceeds that for portland blast-furnace slag cement. where they will be further treated or processed. cement, white—portland cement that hydrates to a white checking—development of shallow cracks at closely spaced paste; made from raw materials of low iron content, but irregular intervals on the surface of plaster, cement the clinker for which is fired by a reducing flame. paste, mortar, or concrete. (See also cracks and crazing.) cement-aggregate ratio—see ratio, aggregate-cement. chemical bond—see bond, chemical. cement bacillus—see ettringite (preferred term). chemically prestressing cement—see cement, chemically cement-bound macadam—see macadam, cement-bound. prestressing. cement content—quantity of cement contained in a con- chemically prestressing concrete—see concrete, chemi- crete, mortar, or grout, preferably expressed as mass per cally prestressing. unit volume of concrete, mortar, or grout. chert—a very fine-grained siliceous rock characterized by a cement factor—see cement content (preferred term). variety of colors, by hardness and conchoidal fracture in cement gel—see gel, cement. dense varieties, and the fracture becoming splintery and cement gun—see gun, cement. the hardness decreasing in porous varieties; it is com- cement kiln—see kiln, cement. posed of silica in the form of chalcedony, cryptocrystal- cement paint—see paint, cement. line or microcrystalline quartz, opal, or combinations of cement paste—binder of concrete and mortar consisting es- any of these minerals. sentially of cement, water, hydration products, and any chipping—treatment of a hardened concrete surface by admixtures together with very finely divided materials in- chiseling. cluded in the aggregates. (See also cement paste, neat.) chips—broken fragments of marble or other mineral aggre- cement paste, neat—a plastic mixture of hydraulic cement gate screened to specified sizes. and water both before and after setting and hardening. chord modulus—see modulus of elasticity. cement plaster—see plaster and stucco. cement rock—natural impure limestone that contains the chute—a sloping trough or tube for conducting concrete, ce- ingredients for production of portland cement in approx- ment, aggregate, or other free flowing materials from a imately the required proportions. higher to a lower point. cementation process—the process of injecting cement clamp—see coupler (preferred term). grout under pressure into certain types of ground (for ex- class (of concrete)—an arbitrary characterization of con- ample, gravel, or fractured rock) to solidify it. crete of various qualities or usages, usually by compres- cementitious—having cementing properties. sive strength. cementitious materials—see materials, cementitious. 

%      #    cementitious mixture—a mixture (mortar, concrete, or # ((  # ! # (#  grout) containing hydraulic cement. (   % %# $   #   center matched—tongue-and-groove lumber with the ( # (    µ!#      tongue and groove at the center of the piece rather than % % %  # ##   % & offset as in standard matched. (See also standard  %  #  matched.) clay, fire—an earthy or stony mineral aggregate that has as centering—falsework used in the construction of arches, the essential constituent hydrous silicates of aluminum shells, space structures, or any continuous structure with or without free silica, and that is plastic when suffi- where the entire falsework is lowered (struck or decen- ciently pulverized and wetted, rigid when subsequently tered) as a unit. (See also falsework and formwork.) dried, and of suitable refractoriness for use in commercial central-mixed concrete—see concrete, central-mixed. refractory products.

CEMENT AND CONCRETE TERMINOLOGY 116R-13 clay clay content—mass fraction of clay of a heterogeneous ma- coating, form—a liquid applied to formwork surfaces for a terial, such as a soil or a natural concrete aggregate or specific purpose, such as to promote easy release from the crushed stone. concrete, to preserve the form material, or to retard setting cleanout—an opening in the forms for removal of refuse, to of the near-surface matrix for preparation of exposed-ag- be closed before the concrete is placed; a port in tanks, gregate finishes. bins, or other receptacles for inspection and cleaning. cobble—in geology, a rock fragment between 2-1/2 and 10 cleanup—treatment of horizontal construction joints to re- in. (64 and 256 mm) in diameter; as applied to coarse ag- move surface material and contamination down to a con- gregate for concrete, the material in the nominal size dition of soundness corresponding to that of a freshly range (3 to 6 in. [75 to 150 mm]). broken surface of hardened concrete. cobblestone—a rock fragment, usually rounded or semir- cleat—small board used to connect formwork members or ounded, with an average dimension between 3 and 12 in. used as a brace. (See also batten.) (75 and 300 mm). climbing form—see form, climbing. coefficient of subgrade friction—the coefficient of friction clinker—a partially fused product of a kiln, which is ground between a slab and its subgrade, commonly used in design to make cement; also other vitrified or burnt material. of slabs-on-grade to estimate the force induced in the slab (See also clinker, portand-cement.) due to volume changes and elastic shortening if pre- clinker, portland-cement—a partially fused ceramic mate- stressed. rial consisting primarily of hydraulic calcium silicates and coefficient of subgrade reaction—ratio of: a) load per unit calcium aluminates. (See also clinker.) area of horizontal surface of a mass of soil; to b) corre- clip—wire or sheet-metal device used to attach various types sponding settlement of the surface; determined as the of lath to supports or to secure adjacent lath sheets. slope of the secant, drawn between the point correspond- closed-circuit grouting—see grouting, closed-circuit. ing to zero settlement and the point of 0.05 in. (1.3 mm) coarse aggregate—see aggregate, coarse. settlement, of a load-settlement curve obtained from a coarse-aggregate factor—see factor, coarse-aggregate. plate load test on a soil using a 30 in. (762 mm) or greater coarse-grained soil—see soil, coarse-grained. diameter loading plate; used in the design of concrete coat—a film or layer as of paint or plaster applied in a single pavements by the Westergaard method; also called mod- operation. ulus of subgrade reaction or subgrade modulus. coat, brown—the second coat in three-coat plaster appli- coefficient of thermal expansion—change in linear dimen- cation. sion per unit length or change in volume per unit volume coat, dash-bond—a thick slurry of portland cement, per degree of temperature change. sand, and water flicked on surfaces with a paddle or coefficient of variation (V)—the standard deviation ex- brush to provide a base for subsequent portland ce- pressed as a percentage of the average. (See also stan- ment plaster coats; sometimes used as a final finish on dard deviation.) plaster. cold-drawn wire reinforcement—see reinforcement, coat, finish—final thin coat of shotcrete preparatory to cold-drawn wire. hand finishing; also exposed coat of plaster and stuc- cold face—the surface of a refractory section not exposed to co. the source of heat; surface of concrete or masonry ex- coat, flash—a light coat of shotcrete used to cover minor posed to low ambient temperatures. blemishes on a concrete surface. cold joint—see joint, cold. coat, scratch—the first coat of plaster or stucco applied cold-joint lines—visible lines on the surfaces of formed to a surface in three-coat work; usually cross-raked or concrete indicating the presence of discontinuities where scratched to form a mechanical key with the brown one layer of concrete had hardened before subsequent coat. concrete was placed. (See also joint, cold.) coated bar—see bar, coated. cold strength—see strength, cold. coating— cold-water paint—see paint, cold-water. 1. on concrete—material applied to a surface by brushing, cold weather—a period in which for more than three succes- dipping, mopping, spraying, troweling, etc., to pre- sive days the average daily outdoor temperature drops be- serve, protect, decorate, seal, or smooth the substrate; low 40 F (5 C). Note: The average daily temperature is the 2. on aggregate particles—foreign or deleterious sub- average of the highest and lowest temperature during the stances found adhering to the aggregate particles; or period from midnight to midnight. When temperatures 3. on architectural concrete—material used to protect a above 50 F (10 C) occur during more than half of any 24-h concrete surface from atmospheric contaminants and duration, the period shall no longer be regarded as cold those that penetrate slightly and leave a visible clear or weather. pigmented film on the surface. (See also sealer.) cold-worked steel reinforcement—see reinforcement, cold- coating, polysulfide—a protective-coating system prepared worked steel. by polymerizing a chlorinated alkyl polyether with an in- colemanite—a mineral, hydrated calcium borate ⋅ organic polysulfide. (Ca2B6O11 5H2O). (See also concrete, boron-loaded.)

116R-14 ACI COMMITTEE REPORT concrete colloid—a substance that is in a state of division preventing component, expansive—the portion of an expansive cement passage through a semipermeable membrane, consisting that is responsible for the expansion, generally one of sev- of particles ranging from 0.1 to 0.001 mm in diameter. eral anhydrous calcium aluminate or sulfoaluminate com- colloidal concrete—see concrete, colloidal. pounds and a source of sulfate, with or without free lime, colloidal mixer—see mixer, colloidal. (CaO); the expansive component may be produced sepa- colloidal grout—see grout, colloidal. rately and later ground or blended with a normal portland- colloidal particle—see particle, colloidal. cement clinker; in other instances, produced by firing in a colorimetric value—an indication of the amount of organic kiln with the constituents of portland cement. impurities present in fine aggregate. composite column—see column, composite. column—a member used primarily to support axial com- composite concrete flexural members—concrete flexural pression loads and with a height of at least three times its members consisting of concrete elements constructed in least lateral dimension. separate placements but so interconnected that the ele- column, composite—a concrete compression member ments respond to loads as a unit. reinforced longitudinally with structural steel shapes, composite construction—see construction, composite. pipe, or tubing with or without longitudinal reinforc- composite pile—see pile, composite. ing bars. composite sample—see sample, composite. column, long—a column whose load capacity is limited compound, curing—a liquid that can be applied as a coating by buckling rather than strength. (See also column, to the surface of newly placed concrete to retard the loss slender.) of water or, in the case of pigmented compounds, and also column, pipe—a column made of steel pipe; often filled to reflect heat so as to provide an opportunity for the con- with concrete. crete to develop its properties in a favorable temperature column, short—a column whose load capacity is lim- and moisture environment. (See also curing and curing, ited by strength rather than buckling; a column that membrane.) is customarily so stocky and sufficiently restrained compound, joint-sealing—an impervious material used to that at least 95% of the cross-sectional strength can fill joints in pavements or structures. be developed. compound, sealing—see sealer. column, slender—a column whose load capacity is re- compound, waterproofing—material used to impart water duced by the increased eccentricity caused by second- repellency to a structure or a constructional unit. ary deflection moments. compression flange—see flange, compression. column, spirally reinforced—a column in which the compression member—see member, compression. vertical bars are enveloped by spiral reinforcement, compression reinforcement—see reinforcement, com- that is, closely spaced continuous hooping. pression. column, tied—a column laterally reinforced with ties. compression test—see test, compression. column capital—an enlargement of a column below a slab compressive strength—see strength, compressive. intended to increase the shearing resistance. compressive-strength, average—the average compressive column clamp—any of various types of tying or fastening strength of a given class or strength level of concrete; in units to hold column form sides together. ACI 214, defined as average compressive strength re- column side—one of the vertical panel components of a col- quired to statistically meet a designated specific strength. umn form. compressive stress—see stress. column strip—the portion of a flat slab over the columns concentric tendons—see tendons, concentric. and consisting of the two adjacent quarter panels on each concordant tendons—see tendons, concordant. side of the column center line. concrete—a composite material that consists essentially of a combined-aggregate grading—see grading, combined- binding medium within which are embedded particles or aggregate. fragments of aggregate, usually a combination of fine ag- combined footing—see footing, combined. gregate and coarse aggregate; in portland-cement con- come-along — crete, the binder is a mixture of portland cement and 1. a hoe-like tool with a blade approximately 4 in. (100 water, with or without admixtures. mm) high and 20 in. (500 mm) wide and curved from concrete, aerated—see concrete, foamed and concrete, top to bottom, used for spreading concrete; or cellular. 2. a colloquial name for a device (load binder) used to concrete, aluminate—concrete made with calcium-alu- tighten chains holding loads in place on a truck bed. minate cement; used primarily where high-early- compacting factor—the ratio obtained by dividing the ob- strength and refractory or acid-resistant concrete is re- served mass of concrete that fills a container of standard quired. size and shape when allowed to fall into it under standard concrete, architectural—concrete that will be permanent- conditions of test, by the mass of fully compacted con- ly exposed to view and therefore requires special care in crete which fills the same container. selection of the concrete materials, forming, placing, and compaction—see consolidation (preferred term). finishing to obtain the desired architectural appearance.

CEMENT AND CONCRETE TERMINOLOGY 116R-15 concrete

concrete, asphaltic—a mixture of asphalt cement and concrete, fair-face—a concrete surface that, on comple- aggregate. tion of the forming process, requires no further (con- concrete, backfill—nonstructural concrete used to cor- crete) treatment other than curing. (See also concrete, rect over-excavation, fill excavated pockets in rock, or architectural.) prepare a surface to receive structural concrete. concrete, fat—concrete containing a relatively large concrete, boron-loaded—high density concrete includ- amount of plastic and cohesive mortar. ing a boron-containing admixture or aggregate, such as concrete, fiber-reinforced—concrete containing dis- the mineral colemanite, boron frits, or boron metal al- persed, randomly oriented fibers. loys, to act as a neutron attenuator. (See also biological concrete, fibrous—see concrete, fiber-reinforced. shielding and concrete, shielding.) concrete, field—concrete delivered or mixed, placed, and concrete, cast-in-place—concrete that is deposited and al- cured on the job site. lowed to harden in the place where it is required to be in concrete, flowing—concrete that is characterized by a the completed structure, as opposed to precast concrete. slump greater than 7-1/2 in. (190 mm) while remaining concrete, cellular—a low-density product consisting of cohesive. portland cement, cement-silica, cement-pozzolan, lime- concrete, foamed—low-density concrete made by the pozzolan, lime-silica pastes, or pastes containing blends addition of a prepared foam or by generation of gas of these ingredients and having a homogeneous void or within the unhardened mixture. cell structure, attained with gas-forming chemicals or concrete, fresh—concrete that possesses enough of its foaming agents (for cellular concretes containing binder original workability so that it can be placed and con- ingredients other than, or in addition to, portland ce- solidated by the intended methods. ment, autoclave curing is usually employed). concrete, gap-graded—concrete containing a gap-grad- concrete, central-mixed—concrete that is completely ed aggregate. mixed in a stationary mixer from which it is transport- concrete, gas—lightweight concrete produced by devel- ed to the delivery point. oping voids with gas generated within the fresh mix- concrete, centrifugally cast—concrete compacted by ture (usually from the action of cement alkalies on centrifugal action, for example, in the manufacture of aluminum powder used as an admixture). (See also pipe and poles. (See also centrifugal process.) concrete, foamed.) concrete, chemically prestressing—concrete made with concrete, granolithic—concrete suitable for use as a expansive cement and reinforcement under conditions wearing surface finish to floors, made with specially such that the expansion of the cement induces tensile selected aggregate of suitable hardness, surface tex- stress in the reinforcement so as to produce prestressed ture, and particle shape. concrete. concrete, green—concrete that has set but not hardened concrete, colloidal—concrete in which the aggregate is appreciably. bound by colloidal grout. concrete, grouted-aggregate—see concrete, preplaced- concrete, confined—concrete containing closely spaced aggregate. special transverse reinforcement that is provided to re- concrete, gypsum—concrete in which the cementitious strain the concrete in directions perpendicular to the constituent is partially dehydrated calcium sulfate applied stress. (plaster). concrete, cyclopean—mass concrete in which large concrete, hardened—concrete that has developed suffi- stones, each of 100 lb (50 kg) or more, are placed and cient strength to serve some purpose or resist breaking embedded in the concrete as it is deposited. (See also under stipulated loading. concrete, rubble.) concrete, heat-resistant—any concrete that will not dis- concrete, dense—concrete containing a minimum of integrate when exposed to constant or cyclic heating at voids. any temperature below that at which a ceramic bond is concrete, dry-mix—concrete of very low water content formed. used in the dry-cast process. (See also process, dry- concrete, heavy—see concrete, high-density (preferred cast.) term). concrete, dry-packed—concrete placed by dry packing. concrete, heavyweight—see concrete, high-density concrete, epoxy—a mixture of epoxy resin and catalyst (preferred term). (binder), fine aggregate, and coarse aggregate. (See concrete, high-density—concrete of substantially higher also concrete, polymer, mortar, epoxy; and resins, density than that made using normal-density aggre- epoxy.) gates, usually obtained by use of high-density aggre- concrete (mortar or grout), expansive-cement—con- gates and used especially for radiation shielding. crete (mortar or grout) made with expansive cement. concrete, high-early-strength—concrete which, through concrete, exposed—concrete surfaces formed so as to the use of high-early-strength cement or admixtures, at- yield an acceptable texture and finish for permanent tains a given level of strength earlier than normal con- exposure to view. (See also concrete, architectural.) crete does.

116R-16 ACI COMMITTEE REPORT concrete concrete, high-strength—concrete that has a specified concrete, plain—structural concrete with no reinforce- compressive strength for design of 6000 psi (41 MPa) ment or with less reinforcement than the minimum or greater. amount specified in ACI 318 for reinforced concrete; concrete, high-performance—concrete meeting special also used loosely to designate concrete containing no combinations of performance and uniformity require- admixture and prepared with no special treatment. ments that cannot always be achieved routinely using concrete, polymer—concrete in which an organic poly- conventional constituents and normal mixing, placing, mer serves as the binder; also known as resin concrete; and curing practices. sometimes erroneously employed to designate hydrau- concrete, in-situ—see concrete, cast-in-place (pre- lic cement mortars or concretes in which part or all of ferred term). the mixing water is replaced by an aqueous dispersion concrete, insulating—concrete having low thermal con- of a thermoplastic copolymer. (See also concrete.) ductivity; used as thermal insulation. (See also con- concrete, polymer-cement—a mixture of water, hydrau- crete, lightweight and concrete, low-density.) lic cement, aggregate, and a monomer or polymer; po- concrete, lean—concrete of low cementitious material lymerized in place when a monomer is used. content. concrete, popcorn—no-fines concrete containing insuf- concrete, lightweight—concrete of substantially lower ficient cement paste to fill voids among the coarse ag- density than that made using aggregates of normal gregate so that the particles are bound only at points of density. (See also concrete, insulating and concrete, contact. (See also concrete, no-fines.) low-density.) concrete, precast—concrete cast elsewhere than its final concrete, low-density—concrete having an oven-dry position. density of less than 50 lb/ft3 (800 kg/m3). (See also concrete, prepacked—see concrete, preplaced-aggre- concrete, insulating and concrete, lightweight.) gate. concrete, mass—any volume of concrete with dimensions concrete, preplaced-aggregate—concrete produced by large enough to require that measures be taken to cope placing coarse aggregate in a form and later injecting a with generation of heat from hydration of the cement portland cement-sand grout, usually with admixtures, and attendant volume change, to minimize cracking. to fill the voids. concrete, monolithic—concrete cast with no joints other concrete (mortar, grout), preshrunk— than construction joints. 1. concrete that has been mixed for a short period in a concrete, nailable—concrete, usually made with a suit- stationary mixer before being transferred to a transit able low-density aggregate, with or without the addi- mixer, or tion of sawdust, into which nails can be driven. 2. grout, mortar, or concrete that has been mixed one concrete, negative-slump—concrete of a consistency to three hours before placing to reduce shrinkage such that it not only has zero slump but still has zero during hardening. slump after adding additional water. (See also con- concrete, prestressed—concrete in which internal stress- crete, zero-slump and concrete, no-slump.) es of such magnitude and distribution are introduced concrete, no-fines—a concrete mixture containing little that the tensile stresses resulting from the service loads or no fine aggregate. are counteracted to a desired degree; in reinforced con- concrete, nonair-entrained—concrete in which neither crete the prestress is commonly introduced by tension- an air-entraining admixture nor air-entraining cement ing the tendons. has been used. concrete, pumped—concrete which is transported concrete, nonslip— through hose or pipe by means of a pump. 1. a floor, pavement, or walkway of concrete the sur- concrete, ready-mixed—concrete manufactured for de- face of which has been roughened, before final set, livery to a purchaser in a fresh state. (See also con- either by sprinkling fine particles of abrasive mate- crete, central-mixed; concrete, shrink-mixed; and rial thereon and then troweling or by swirling with concrete, transit-mixed.) either a coarse-bristled brush or a trowel; or concrete, recycled—hardened concrete that has been 2. a concrete surfaced roughened after final set by acid processed for reuse, usually as aggregate. etching, mechanically abrading, or grooving. concrete, refractory—hardened hydraulic-cement con- concrete, normalweight—concrete having a density of crete that has refractory properties and that is suitable approximately 150 lb/ft3 (2400 kg/m3) made with nor- for use at temperatures between 600 and 2400 F (315 mal-density aggregates. to 1315 C). concrete, normalweight refractory—refractory con- concrete, refractory-insulating—refractory concrete hav- crete having a bulk density greater than 100 lb/ft3 ing low thermal conductivity. (1600 kg/m3). concrete, reinforced—structural concrete reinforced concrete, no-slump—freshly mixed concrete exhibiting with no less than the minimum amount of prestressing a slump of less than 1/4 in. (6 mm). (See also concrete, tendons or nonprestressed reinforcement as specified zero-slump and concrete, negative-slump.) by ACI 318.

CEMENT AND CONCRETE TERMINOLOGY 116R-17 concrete

concrete, resin—see concrete, polymer (preferred concrete, truck-mixed—see concrete, transit-mixed. term). concrete, underwater—concrete placed underwater by concrete, rich—concrete of high cement content. (See tremie or other means. also concrete, lean.) concrete, unhardened—see concrete, fresh (preferred concrete, roller-compacted—concrete compacted by term). roller compaction; concrete that, in its unhardened concrete, unreinforced—see concrete, plain. state, will support a roller while being compacted. concrete, vacuum—concrete from which excess water concrete, rubble— and entrapped air are extracted by a vacuum process 1. concrete similar to cyclopean concrete except that before hardening occurs. small stones (such that one person can handle concrete, vermiculite—concrete in which the aggregate them) are used. consists of exfoliated vermiculite. 2. concrete made with rubble from demolished struc- concrete, vibrated—concrete consolidated by vibration tures. (See also concrete, cyclopean.) during and after placing. concrete, sand-lightweight—concrete made with a com- concrete, visual—see concrete, exposed and concrete, bination of expanded clay, shale, slag, or slate or sin- architectural. tered fly ash and natural sand; its density is generally concrete, zero-slump—concrete of stiff or extremely dry between 105 and 120 lb/ft3 (1680 and 1920 kg/m3). consistency showing no measurable slump after re- concrete, sawdust—concrete in which the aggregate con- moval of the slump cone. (See also slump; concrete, sists mainly of sawdust from wood. no-slump; and concrete, negative-slump.) concrete (mortar or grout), self-stressing—expansive- concrete block—see block, concrete. cement concrete (mortar or grout) in which expansion, concrete breaker—a compressed-air tool specially de- if restrained, induces persistent compressive stresses in signed and constructed to break up concrete. the concrete (mortar or grout); also known as chemi- concrete brick—see brick, concrete. cally prestressed concrete. concrete cart—see buggy. concrete, shielding—concrete, employed as a biological concrete containment structure—a composite concrete shield to attenuate or absorb nuclear radiation, usually and steel assembly that is designed as an integral part of a characterized by high density or high hydrogen (water) pressure retaining barrier, which in an emergency pre- content or boron content, having specific radiation at- vents the release of radioactive or hazardous effluents tenuation effects. (See also biological shielding.) from nuclear power plant equipment enclosed therein. concrete, shrink-mixed—ready-mixed concrete mixed concrete finishing machine—a machine mounted on partially in a stationary mixer and then mixed in a truck flanged wheels that ride on the forms or on specially set mixer. (See also concrete, preshrunk.) tracks, used to finish surfaces such as those of pavements; concrete, shrinkage-compensating—concrete contain- or a portable power-driven machine for floating and fin- ing expansive components usually based on the forma- ishing of floors and other slabs. tion of calcium sulfoaluminate (ettringite) in a mixture concrete flatwork—see flatwork, concrete. of calcium aluminate and gypsum. (See also cement, concrete masonry unit—see masonry unit, concrete. expansive.) concrete paver—see paver, concrete. concrete, siliceous-aggregate—concrete made with nor- concrete pile—see pile, cast-in-place and pile, precast. mal-density aggregates having constituents composed concrete pump—see pump, concrete. mainly of silica or silicates. concrete reactor vessel—a composite concrete and steel as- concrete, sprayed—see shotcrete (preferred term). sembly that functions as a component of the principal concrete, spun—see concrete, centrifugally cast (pre- pressure-containing barrier for the nuclear fuel’s primary ferred term). heat extraction fluid (primary coolant). concrete, structural—concrete used to carry load. concrete spreader—see spreader, concrete. concrete, structural lightweight—structural concrete concrete strength—see strength, compressive; strength, fa- made with low-density aggregate; having an air-dry tigue; strength, flexural; strength, shear; strength, split- density of not more than 115 lb/ft3 (1850 kg/m3) and a ting tensile; strength, tensile; and strength, ultimate. 28-day compressive strength of more than 2500 psi concrete vibrating machine—a machine that consolidates a (17.2 MPa). layer of freshly mixed concrete by vibration. concrete, subaqueous—see concrete, underwater. condensed silica fume—see silica fume (preferred term). concrete, terrazzo—marble-aggregate concrete that is conductance, thermal—time rate of heat flow through a cast-in-place or precast and ground smooth for decora- unit area of body induced by a unit temperature difference tive surfacing purposes on floors and walls. between the body surfaces; the thermal conductance is the concrete, transit-mixed—concrete, the mixing of which reciprocal of the thermal resistance. is wholly or principally accomplished in a truck mixer. conductivity, thermal—the property (of a homogeneous concrete, translucent—a combination of glass and con- body) measured by the ratio of the steady-state heat flux crete used together in precast and prestressed panels. (time-rate of heat flow per unit area) to the temperature.

116R-18 ACI COMMITTEE REPORT continuous cone— 100 to 125% at five drops on the ASTM C 230 flow cone, flow—a device for measurement of grout consis- table. tency in which a predetermined volume of grout is consistency, wettest stable—the condition of maximum permitted to escape through a precisely sized orifice, water content at which cement grout and mortar will the time of efflux (flow factor) being used as the indi- adhere to a vertical surface without sloughing. cation of consistency; also the mold used to prepare a consistency factor—a measure of grout fluidity, roughly specimen for the flow test. analogous to viscosity, which describes the ease with cone, pyrometric—a small, slender, three-sided oblique which grout may be pumped into voids or fissures; usu- pyramid made of ceramic or refractory material for ally a laboratory measurement in which consistency is use in determining the time-temperature effect of heat- reported in degrees of rotation of a torque viscosimeter ing and in obtaining the pyrometric cone equivalent in a specimen of grout. (PCE) of refractory material. consistometer—an apparatus for measuring the consistency cone, slump—a mold in the form of the lateral surface of the of cement pastes, mortars, grouts, or concretes. frustum of a cone with a base diameter of 8 in. (203 mm), consolidation—the process of inducing a closer arrange- top diameter of 4 in. (102 mm), and height of 12 in. (305 ment of the solid particles in freshly mixed concrete or mm), used to fabricate a specimen of freshly mixed mortar during placement by the reduction of voids, usual- concrete for the slump test; a cone 6 in. (152 mm) high ly by vibration, centrifugation, rodding, tamping, or some is used for tests of freshly mixed mortar and stucco. combination of these actions; also applicable to similar cone bolt—a type of tie rod for wall forms with cones at manipulation of other cementitious mixtures, soils, aggre- each end inside the forms so that a bolt can act as a gates, or the like. (See also rodding and tamping.) spreader as well as a tie. construction— confined concrete—see concrete, confined. construction, alternate-lane—a method of constructing confined region—region with transverse reinforcement soil-supported concrete roads, runways, building within beam-column joints. floors, or other paved areas, in which alternate lanes are placed and allowed to harden before the remaining connection, scarf—a connection made by precasting, bev- intermediate lanes are placed. eling, halving, or notching two pieces to fit together; after construction, cellular—a method of constructing con- overlapping, the pieces are secured by bolts or other crete elements in which part of the interior concrete is means. replaced by voids. consistency—the relative mobility or ability of freshly construction, composite—a type of construction using mixed concrete or mortar to flow; the usual measure- members produced by combining different materials ments are slump for concrete, flow for mortar or grout, (for example, concrete and structural steel); members and penetration resistance for neat cement paste. produced by combining cast-in-place and precast con- consistency, flowable—the consistency at which a grout crete, or cast-in-place concrete elements constructed in will form a nearly level surface when lightly rodded; the separate placements but so interconnected that the consistency of a grout with at least 125% at five drops combined components act together as a single member on the ASTM C 230 flow table and an efflux time and respond to loads as a unit. through the ASTM C 939 flow cone of more than 30 s. construction, shell—construction using thin curved consistency, fluid—the consistency at which a grout will slabs. form a nearly level surface without vibration or rod- construction, structural sandwich—a laminar construc- ding; the consistency of a grout that has an efflux time tion comprising a combination of alternating dissimi- of less than 30 s from the ASTM C 939 flow cone. lar simple or composite materials assembled and consistency, normal— intimately fixed in relation to each other so as to use 1. the degree of wetness exhibited by a freshly mixed the properties of each to attain specific structural and concrete, mortar, or neat cement grout when the thermal advantages for the whole assembly. workability of the mixture is considered acceptable construction joint—see joint, construction. for the purpose at hand; or construction loads—the loads to which a permanent or tem- 2. the physical condition of neat cement paste as deter- porary structure is subjected during construction. mined with the Vicat apparatus in accordance with a contact ceiling—a ceiling that is secured in direct contact standard method test (for example, ASTM C 187). with the construction above without use of furring. consistency, plastic— contact pressure—pressure acting at and perpendicular to 1. condition of freshly mixed cement paste, mortar, or the contact area between soil and a concrete element. concrete such that deformation when a stress is ap- contact splice—see splice, contact. plied will be sustained continuously in any direc- containment grouting—see grouting, perimeter. tion without rupture; or continuous beam—see continuous slab or beam. 2. the consistency at which a grout will form a nearly continuous footing—see footing, continuous. level surface only when rodded or vibrated with a vi- continuous grading—see grading, continuous. brator, the consistency of a grout with a flow between continuous mixer—see mixer, continuous.

CEMENT AND CONCRETE TERMINOLOGY 116R-19 continuous continuous sampling—see sampling, continuous. cored beam—a beam whose cross section is partially hol- continuous slab or beam—a slab or beam that extends as a low or a beam from which cored samples of concrete have unit over three or more supports in a given direction. been taken. continuously reinforced pavement—a pavement with un- coring—the act of obtaining cores from hardened concrete interrupted longitudinal steel reinforcement and no inter- or masonry structures, rock, or soil. mediate transverse expansion or contraction joints. corner reinforcement—see reinforcement, corner. contract documents—see documents, contract. corrosion—destruction of metal by a chemical, electro- contraction—decrease in either length or volume. (See also chemical, or electrolytic reaction within its environment. expansion; shrinkage; swelling; volume change; and corrosion, bacterial—destruction of a material by bacterial volume change, autogenous.) processes brought about by the activity of certain bacteria contraction, thermal—see thermal contraction. that consume the material and produce substances, such contraction joint—see joint, contraction. as hydrogen sulfide, ammonia, and sulfuric acid. contraction-joint grouting—see grouting, contraction- corrosion inhibitor—a chemical compound, either liquid or joint. powder, usually intermixed in concrete and sometimes contractor—the person, firm, or corporation with whom the applied to concrete, and that effectively decreases corro- owner enters into an agreement for construction of the sion of steel reinforcement. work. cotton mats—see mats, cotton. control factor—the ratio of the minimum compressive coupler— strength to the average compressive strength. 1. a device for connecting reinforcing bars or prestress- control joint—see joint, contraction (preferred term). ing tendons end to end; control-joint grouting—see grouting, contraction-joint. 2. a device for locking together the component parts of a tubular metal scaffold (also known as a clamp); or controlled low-strength cementitious material—material 3. internal threaded device for joining reinforcing bars that is intended to result in a compressive strength of 1200 with matching threaded ends for the purpose of provid- psi (8.3 MPa) or less. ing transfer of either axial compression or axial tension conventional design—design procedure using moments or or both from one bar to the other. (See also coupling stresses determined by widely accepted methods. sleeve, end-bearing sleeve, mechanical connection.) conveying hose—see hose, delivery (preferred term). coupling agent—a substance used between the transduc- conveyor—a device for moving materials; usually a contin- er and test surface to permit or improve transmission uous belt, an articulated system of buckets, a confined of ultrasonic energy. screw, or a pipe through which material is moved by air coupling pin—an insert device used to connect lifts or tiers or water. or formwork scaffolding vertically. coping—the material or units used to form a cap or finish on coupling sleeve—device fitting over the ends of two rein- top of a wall, pier, pilaster, or chimney. forcing bars for the eventual purpose of providing transfer coquina—a type of limestone formed of sea shells in loose of either axial compression or axial tension or both from or weakly cemented condition, found along present or one bar to the other. (See also coupler, end-bearing former shorelines; used as a calcareous raw material in ce- sleeve, mechanical connection.) ment manufacture and other industrial operations. course—in concrete construction, a horizontal layer of con- corbel—a projection from the face of a beam, girder, col- crete, usually one of several making up a lift; in masonry umn, or wall used as a beam seat or a decoration. construction, a horizontal layer of block or brick. (See core (n.)— also lift.) 1. the soil material enclosed within a tubular pile after cover—in reinforced concrete, the least distance between driving (it may be replaced with concrete); the surface of embedded reinforcement and the outer sur- 2. the mandrel used for driving casings for cast-in-place face of the concrete. piles; cover block—see spacer and spreader (preferred terms). 3. a structural shape used to internally reinforce a drilled- crack—a complete or incomplete separation, of either con- in-caisson; crete or masonry, into two or more parts produced by 4. a cylindrical sample of hardened concrete or rock ob- breaking or fracturing. (See also fracture.) tained by means of a core drill; crack, diagonal—in a flexural member, an inclined crack 5. the molded open space in a concrete masonry unit or caused by shear stress, usually at approximately 45 de- precast concrete unit (see also blockout); or grees to the axis; or a crack in a slab, not parallel to ei- 6. the area enclosed by ties or spiral reinforcement in a ther the lateral or longitudinal directions. concrete column. crack, longitudinal—a crack that develops parallel to the core (v.)—the act of obtaining cores from concrete struc- length of a member. tures, rock foundations, or soils. crack, shrinkage—crack due to restraint of shrinkage. core test—compression test on a concrete sample cut from crack-control reinforcement—see reinforcement, hardened concrete by means of a core drill. crack-control.

116R-20 ACI COMMITTEE REPORT curing cracked section—a section designed or analyzed on the as- creep, drying—creep caused by drying. (See creep; and sumption that concrete has no resistance to tensile stress. creep, basic.) cracking— creep, nonrecoverable—the residual or nonreversible de- cracking, diagonal—development of diagonal cracks. formation remaining in hardened concrete after removal (See also tension, diagonal.) of sustained load. cracking, map— crimped wire—see wire, crimped. 1. intersecting cracks that extend below the surface of critical saturation—see saturation, critical. hardened concrete; caused by shrinkage of the dry- cross bracing—crossing members usually designed to act ing surface concrete that is restrained by concrete at only in tension, often used in scaffolding systems. (See greater depths where either little or no shrinkage also sway brace and X-brace.) occurs; vary in width from fine and barely visible cross joint—see joint, cross. to open and well-defined; or cross section—a plane through a body perpendicular to a 2. the chief symptom of a chemical reaction between given axis of the body; a drawing showing such a plane. alkalies in cement and mineral constituents in aggre- gate within hardened concrete; due to differential cross-tee—a light-gage metal member resembling an up- rate of volume change in different portions of the side-down “tee” used to support the abutting ends of concrete; cracking is usually random and on a fairly formboards in insulating concrete roof constructions. large scale, and in severe instances the cracks may crush plate—an expendable strip of wood attached to the reach a width of 0.50 in. (12.7 mm). (See also check- edge of a form or intersection of fitted forms, to protect ing and crazing; also known as pattern cracking.) the form from damage during prying, pulling, or other cracking, pattern—see cracks and cracking, map. stripping operations. (See also strip, wrecking.) cracking, plastic—cracking that occurs in the surface of crushed gravel—see gravel, crushed. fresh concrete soon after it is placed and while it is still crushed stone—see stone, crushed. plastic. crusher— cracking, shrinkage—cracking of a structure or member crusher, primary—a heavy crusher suitable for the first due to failure in tension caused by external or internal stage in a process of size reduction of rock, slag, or the restraints as reduction in moisture content develops, like. carbonation occurs, or both. crusher, secondary—a crusher used for the second stage cracking, stress-corrosion—a cracking process that re- in a process of size reduction of aggregate and the like. quires the simultaneous action of a corrodent and sus- (See also crusher, primary.) tained tensile stress. (This excludes corrosion-reduced crusher-run aggregate—see aggregate, crusher-run. sections that fail by fast fracture; also excludes inter- C/S—the molar or mass ratio, whichever is specified, of cal- crystalline or transcrystalline corrosion that can disinte- cium oxide (CaO) to silicon dioxide (SiO2), usually of grate an alloy without either applied or residual stress). binder materials cured in an autoclave. cracking, temperature—cracking due to tensile failure, cube strength—see strength, cube. caused by a temperature drop in members subjected to cubical piece (of aggregate)—one in which length, breadth, external restraints or by a temperature differential in and thickness are approximately equal. members subjected to internal restraints. cumulative batching—see batching, cumulative. cracking load—see load, cracking. cracks— curb form—a retainer or mold used in conjunction with a cracks, craze—fine random cracks or fissures in a sur- curb tool to give the necessary shape and finish to a con- face of plaster, cement paste, mortar, or concrete. crete curb. cracks, D-line—see D-cracks (preferred term.) curb tool—a tool used to give the desired finish and shape cracks, hairline—cracks in an exposed concrete surface to the exposed surfaces of a concrete curb. having widths so small as to be barely perceptible. curing—action taken to maintain moisture and tempera- cracks, pattern—see cracks and cracking, map. ture conditions in a freshly placed cementitious mixture cracks, plastic shrinkage—see cracking, plastic. to allow hydraulic cement hydration and (if applicable) cracks, transverse—cracks that develop across the long pozzolanic reactions to occur so that the potential prop- dimension of the member. erties of the mixture may develop. (See ACI 308.) craze cracks—see cracks, craze. curing, adiabatic—the maintenance of adiabatic condi- crazing—the development of craze cracks; the pattern of tions in concrete or mortar during the curing period. craze cracks existing in a surface. (See also checking and curing, atmospheric-pressure steam—steam curing of cracks.) concrete products or cement at atmospheric pressure, creep—time-dependent deformation due to sustained load. usually at maximum ambient temperature between 100 (See also deformation, inelastic.) to 200 F (40 to 95 C). creep, basic—creep that occurs without migration of mois- curing, autoclave—curing of concrete products in an au- ture to or from the concrete. (See also creep; and creep, toclave at maximum ambient temperature generally drying.) between 340 to 420 F (170 to 215 C).

CEMENT AND CONCRETE TERMINOLOGY 116R-21 curing

curing, electrical—a system in which a favorable tem- curve, grading—a graphical representation of the propor- perature is maintained in freshly placed concrete by tions of different particle sizes in a granular material; ob- supplying heat generated by electrical resistance. tained by plotting the cumulative or individual curing, fog— percentages of the material passing through sieves in 1. storage of concrete in a moist room in which the de- which the aperture sizes form a given series. sired high humidity is achieved by the atomization cutting screed—see screed, cutting. of water (see also moist room); and cycle, autoclave— the time interval between the start of the 2. application of atomized water to concrete, stucco, temperature-rise period and the end of the blowdown pe- mortar, or plaster. riod; also, a schedule of the time and temperature-pres- curing, high-pressure steam—see curing, autoclave sure conditions of periods which make up the cycle. (preferred term). cyclopean concrete—see concrete, cyclopean. curing, low-pressure steam—see curing, atmospheric- cylinder strength—see strength, compressive and strength, pressure steam. splitting tensile. curing, mass—adiabatic curing in sealed containers. cylinders, field-cured—test cylinders that are left at the job- curing, membrane—a process that involves either liquid site for curing as nearly as practicable in the same manner sealing compound (for example, bituminous and paraf- as the concrete in the structure to indicate when supporting finic emulsions, coal tar cut-backs, pigmented and non forms may be removed, additional construction loads may pigmented resin suspensions, or suspension of wax and be imposed, or the structure may be placed in service. drying oil) or nonliquid protective coating (for exam- ple sheet plastics or “waterproof” paper), both of D which types function as a film to restrict evaporation of mixing water from concrete surfaces. damage, abrasion—wearing away of a surface by rubbing curing, moist-air—curing in air of not less than 95% rel- and friction. (See also damage, cavitation and erosion.) ative humidity at atmospheric pressure and normally at damage, cavitation—pitting of concrete caused by implo- a temperature approximating 73 F (23 C). sion, that is, the collapse of vapor bubbles in flowing wa- curing, single-stage—autoclave curing process in which ter which form in areas of low pressure and collapse as precast concrete products are put on metal pallets for they enter areas of higher pressure. (See also damage, autoclaving and remain there until stacked for delivery abrasion, and erosion.) or yard storage. damp—either partial saturation or moderate covering of curing, standard—exposure of test specimens to speci- moisture; implies less wetness than that connoted by fied conditions of moisture and temperature. (See also “wet” and slightly wetter than that connoted by “moist.” fog curing.) (See also moist and wet.) curing, steam—curing of concrete, mortar, grout, or dampproofing—treatment of concrete or mortar to retard neat-cement paste in water vapor at atmospheric or the passage or absorption of water, or water vapor, either higher pressures and at temperatures between about by application of a suitable coating to exposed surfaces, 100 and 420 F (40 and 215 C). (See also atmospheric- by use of a suitable admixture or treated cement, or by use pressure steam curing, autoclave curing, single- of a preformed film such as polyethylene sheets placed on stage curing, and two-stage curing.) grade before placing a slab. (See also vapor barrier.) curing, two-stage—a process in which concrete products darby—a hand-manipulated straightedge, usually 3 to 8 ft are cured in low-pressure steam, stacked, and then au- (1 to 2.5 m) long, used in the early stage leveling opera- toclaved. tions of concrete or plaster, preceding supplemental curing agent—see catalyst and hardener. floating and finishing. curing blanket—see blanket, curing. dash-bond coat—see coat, dash-bond. curing compound—see compound, curing. day—for concrete, a time period of 24 consecutive hours. curing cycle—see cycle, autoclave and steam-curing cycle. D-cracks—a series of cracks in concrete near and roughly curing delay—see period, prestreaming (preferred term). parallel to joints, edges, and structural cracks. curing kiln—see curing, autoclave. dead end—in the stressing of a tendon from one end only, curing membrane—see membrane curing and curing the end opposite that to which the load is applied. compound. dead-end anchorage—see anchorage, dead-end. curling—the distortion of an originally essentially linear or dead load—see load, dead. planar member into a curved shape, such as the warping of deadman—an anchor for a guy line, usually a beam, block, a slab to differences in temperature or moisture content in or other heavy item buried in the ground, to which a line the zones adjacent to its opposite faces. (See also warping.) is attached. curtain grouting—see grouting, curtain. debonding—procedures whereby specific tendons in pre- curtain reinforcement—see reinforcement, curtain. tensioned construction are prevented from becoming curvature friction—friction resulting from bends or curves bonded to the concrete for a predetermined distance from in the specified prestressing cable profile. the ends of flexural members.

116R-22 ACI COMMITTEE REPORT devil’s decenter—to lower or remove centering or shoring. delay—see period, presteaming. deck—the form on which concrete for a slab is placed, also delivery hose—see hose, delivery. the floor or roof slab itself. (See also deck, bridge.) demold—to remove molds from concrete test specimens or deck, bridge —the structural concrete slab or other struc- precast products. (See also strip.) ture that is supported on the bridge superstructure and dense concrete—see concrete, dense. serves as the roadway or other traveled surface. dense-graded aggregate—see aggregate, dense-graded. decking—sheathing material for a deck or slab form. density—mass per unit volume (preferred over deprecated deflected tendons—see tendons, deflected. term unit weight.) deflection—movement of a point on a structure or struc- density, bulk—the mass of a material (including solid tural element, usually measured as a linear displacement particles and any contained water) per unit volume in- or as succession displacements transverse to a reference cluding impermeable and permeable voids in the mate- line or axis. rial. (See also specific gravity, absolute.) deflection, dowel—deflection caused by the transverse load density, dry—the mass per unit volume of a dry sub- imposed on a dowel. stance at a stated temperature. (See also specific deformation—a change in dimension or shape. (See also gravity, absolute.) contraction; expansion; creep; length change; volume density, dry-rodded—mass per unit volume of dry ag- change; shrinkage; deformation, inelastic; and defor- gregate compacted by rodding under standardized con- mation, time-dependent.) ditions; used in measuring density of aggregate. deformation, anchorage—the loss of elongation or density, fired—the density of refractory concrete, upon stress in the tendons of prestressed concrete due to the cooling, after having been exposed to a specified firing deformation or seating of the anchorage when the pre- temperature for a specified time. stressing force is transferred from the jack to the an- density control—control of density of concrete in field con- chorage; known also as anchorage loss. struction to ensure that specified values as determined by deformation, elastic—elastic deformation proportional standard tests are obtained. to the applied stress. (See also deformation.) depth, effective—depth of a beam or slab section measured deformation, inelastic—nonelastic deformation not pro- from the compression face to the centroid of the tensile re- portional to the applied stress. (See also deformation; inforcement. creep; deformation, time-dependent.) design, elastic—a method of analysis in which the design of a deformation, nonreversible—see creep, nonrecover- member is based on a linear stress-strain relationship and able. corresponding limiting elastic properties of the material. deformation, residual—see creep, nonrecoverable. design, probabilistic—method of design of structures using deformation, time-dependent—deformation resulting the principles of statistics (probability) as a basis for eval- from effects such as autogenous volume change, ther- uation of structural safety. mal contraction or expansion, creep, shrinkage, and design, working-stress—a method of proportioning either swelling, each of which is a function of time. structures or members for prescribed service loads at deformed bar—see bar, deformed. stresses well below the ultimate, and assuming linear dis- deformed plate—see plate, deformed. tribution of flexural stresses and strains. (See also design, deformed reinforcement—see reinforcement, deformed. elastic.) deformed tie bar—see bar, tie. design load—see load, design. degree-hour—a measure of strength gain of concrete as a design strength—see strength, design. function of the product of temperature multiplied by time deterioration— for a specific interval. (See also factor, maturity.) 1. physical manifestation of failure of a material (for ex- dehydration—removal of chemically bound, adsorbed, or ample, cracking, delamination, flaking, pitting, scal- absorbed water from a material. ing, spalling, and staining) caused by environmental or deicer—a chemical, such as sodium or calcium chloride, internal autogenous influences on rock and hardened used to melt ice or snow on slabs and pavements, such concrete as well as other materials; or melting being due to depression of the freezing point. 2. decomposition of material during either testing or ex- delamination—a separation along a plane parallel to a sur- posure to service. (See also disintegration and face, as in the separation of a coating from a substrate or weathering.) the layers of a coating from each other, or in the case of a detritus—loose material produced by the disintegration of concrete slab, a horizontal splitting, cracking, or separa- rocks through geological agencies or processes simulat- tion within a slab in a plane roughly parallel to, and gen- ing those of nature. erally near, the upper surface; found most frequently in development bond stress—see bond stress, anchorage. bridge decks and caused by the corrosion of reinforcing development length—see length, development. steel or freezing and thawing; similar to spalling, scaling, device, anchorage—see anchorage (preferred term). or peeling except that delamination affects large areas device, extension—any device, other than an adjustment and can often only be detected by nondestructive tests, screw, used to obtain vertical adjustment of shoring towers. such as tapping or chain dragging. devil’s float—see float, devil’s.

CEMENT AND CONCRETE TERMINOLOGY 116R-23 diagonal diagonal crack—see crack, diagonal. 45.73% by mass, respectively; a rock containing dolomite diagonal cracking—see cracking, diagonal. as the principal constituent. diagonal tension—see tension, diagonal. dolomite, hard-burned—the product of heating dolomitic diametral compression test—see splitting tensile test. rock at temperatures high enough to change the magne- diamond mesh—see mesh, diamond. sium carbonate to magnesium oxide, a constituent that diatomaceous earth—a friable earthy material composed slowly expands on reaction with water. primarily of nearly pure hydrous amorphous silica (opal) dome—square prefabricated pan form used in two-way in the form of frustules of the microscopic plants called (waffle) concrete joist floor construction. diatoms. double-headed nail—a nail with two heads at, or near, one 
    

 #%      #   end to permit easy removal; widely used in concrete +,⋅" , $$ + "  %(() # $& formwork.  ##%   &# # ."   double-tee beam—see beam, double-tee. differential thermal analysis (DTA)—indication of ther- double-up—a method of plastering characterized by appli- mal reaction by differential thermocouple recording of cation in successive operations with no setting or drying temperature changes in a sample under investigation com- time between coats. pared with those of a thermally passive control sample, doughnut (donut)—a large washer of any shape for increas- that are heated uniformly and simultaneously. ing bearing area of bolts and ties; also a round concrete diffusivity, thermal—thermal conductivity divided by the spacer with a hole in the center to hold bars the desired product of specific heat and density; an index of the facil- distance from the forms. ity with which a material undergoes temperature change. dowel— dilation—an expansion of concrete during cooling or freez- 1. a steel pin, commonly a plain or coated round steel bar ing generally calculated as the maximum deviation from that extends into adjoining portions of a concrete con- the normal thermal contraction predicted from the length struction, as at an expansion or contraction joint in a change-temperature curve or length change-time curve pavement slab, so as to transfer shear loads; or established at temperatures before initial freezing. 2. a deformed reinforcing bar intended to transmit tension, diluent—a substance, liquid or solid, mixed with the active compression, or shear through a construction joint. constituents of a formulation to increase the bulk or lower dowel-bar reinforcement—see dowel. the concentration. dowel deflection—see deflection, dowel. direct dumping—discharge of concrete directly into place dowel lubricant—see lubricant, dowel. from crane bucket or mixer. dowel rod—see rod, dowel. discoloration—departure of color from that which is normal drainage—the interception and removal of water from, on, or desired. or under an area or roadway; the process of removing sur- disintegration—reduction into small fragments and subse- plus ground water or surface water artificially; a general quently into particles. (See also deterioration and weath- term for gravity flow of liquids in conduits. ering.) drainage fill— dispersant—a material that deflocculates or disperses fine- 1. base course of granular material placed between floor ly ground materials by satisfying the surface energy re- slab and sub-grade to impede capillary rise of mois- quirements of the particles; used as a slurry thinner or ture; or grinding aid. 2. lightweight concrete placed on floors or roofs to promote dispersant agent—an agent capable of increasing the fluid- drainage. ity of pastes, mortars, or concretes by reduction of inter- draped tendons—see tendons, deflected (preferred particle attraction. term). displacement, positive—see positive displacement. dried strength—see strength, dried. distortion—see deformation. drier—chemical that promotes oxidation or drying of a paint distress—physical manifestation of cracking and distortion or adhesive. in a concrete structure as the result of stress, chemical ac- drilled pier—see pier, drilled. tion, or both. drip—a transverse groove in the underside of a projecting distribution-bar reinforcement—see reinforcement, dis- piece of wood, stone, or concrete to prevent water from tribution-bar. flowing back to a wall. divider strips—see strips, divider. dropchute—a device used to confine or to direct the flow of D-line cracks—see D-cracks (preferred term). a falling stream of fresh concrete. documents, contract—documents comprising aspects of 1. dropchute, articulated—a device consisting of a suc- the required work and the results and products thereof, in- cession of tapered metal cylinders so designed that the cluding plans, specifications, and project drawings. lower end of each cylinder fits into the upper end of the dolomite—a mineral having a specific crystal structure and one below; or consisting of calcium carbonate and magnesium carbon- 2. dropchute, flexible—a device consisting of a heavy ate in equivalent chemical amounts which are 54.27 and rubberized canvas or plastic collapsible tube.

116R-24 ACI COMMITTEE REPORT electrolyte

drop-in beam—see beam, drop-in. and heat evolution is important; for concrete made with drop panel—see panel, drop. Type I cement stored moist at 73 F (23 C), it is the first 72 h. drop-panel form—see form, drop-panel. early strength—see strength, early. dry-batch weight—see weight, dry-batch. early stiffening—see stiffening, early. dry-cast process—see process, dry-cast. earth pigments—the class of pigments that are produced by dry mix—see mix, dry. physical processing of materials mined directly from the dry-mix concrete—see concrete, dry mix. earth; also frequently termed natural or mineral pigments dry-mix shotcrete—see shotcrete, dry-mix. or colors. dry mixing—see mixing, dry. eccentric tendon—see tendon, eccentric. dry pack—see pack, dry. edge— dry-packed concrete—see concrete, dry-packed. edge, feather—a wood or metal tool having a beveled dry packing—see packing, dry. edge and used to straighten re-entrant angles in finish dry process—see process, dry. plaster coat; also the edge of a concrete or mortar patch dry-rodded density—see density, dry-rodded. or topping that is beveled at an acute angle. dry-rodded volume—see volume, dry-rodded. edge, pressed—edge of a footing along which the greatest dry-rodded weight—deprecated term; see density, dry- soil pressure occurs under conditions of overturning. rodded. edge-bar reinforcement—see reinforcement, edge-bar. dry rodding—see rodding, dry. edge beam—see beam, edge. dry-shake—a dry mixture of hydraulic cement and fine ag- edge form—see form, edge. gregate (either natural or special metallic) that is distrib- edger—a finishing tool used on the edges of fresh concrete uted evenly over the surface of concrete flatwork and to provide a rounded edge. worked into the surface before time of final setting and edging—the operation of tooling the edges of a fresh con- then floated and troweled to desired finish; the mixture crete slab to provide a rounded corner. either may or may not contain pigment. effective area of concrete—area of a concrete section as- dry-tamp process—see packing, dry (preferred term). sumed to resist shear or flexural stresses. dry topping—see dry-shake (preferred term). effective area of reinforcement—the area obtained by mul- dry-volume measurement—measurement of the ingredi- tiplying the right cross-sectional area of the metal rein- ents of grout, mortar, or concrete by their bulk volume. forcement by the cosine of the angle between its drying creep—see creep, drying. centroidal axis and the direction for which its effective- drying shrinkage—see shrinkage, drying. ness is considered. duct—a hole formed in a concrete member to accommodate effective depth—see depth, effective. a tendon for post-tensioning; a pipe or runway for elec- effective flange width—see width, effective flange. tric, telephone, or other utilities. effective prestress—see prestress, effective. ductility—that property of a material by virtue of which it may effective span—see span, effective. undergo large permanent deformation without rupture. effective width of slab—that part of the width of a slab tak- dummy joint—see joint, construction and joint, groove. en into account when designing T- or L-beams. Dunagan analysis—a method of separating the ingredients efflorescence—a deposit of salts, usually white, formed on of freshly mixed concrete or mortar to determine the pro- a surface, the substance having emerged in solution from portions of the mixture. within either concrete or masonry and subsequently durability—the ability of concrete to resist weathering ac- been precipitated by reaction, such as carbonation, or tion, chemical attack, abrasion, and other conditions of evaporation. service. elastic deformation—see deformation, elastic. durability factor—see factor, durability. dust of fracture (in aggregate)—rock dust created during elastic design—see design, elastic. production processing or handling. elastic limit—see limit, elastic. dusting—the development of a powdered material at the elastic loss—see loss, elastic. surface of hardened concrete. elastic modulus—see modulus of elasticity (preferred dye, fugitive—see fugitive dye. term). dynamic analysis—see analysis, dynamic. elastic shortening—see shortening, elastic. dynamic load—see load, dynamic. elasticity—that property of a material by virtue of which it dynamic loading—see loading, dynamic. tends to recover its original size and shape after defor- dynamic modulus of elasticity—see modulus of elasticity, mation. dynamic. electrical curing—see curing, electrical. electrolysis—production of chemical changes by the pas- E sage of current through an electrolyte. electrolyte—a conducting medium in which the flow of cur- early ages (of concrete)—the period following the time of fi- rent is accompanied by movement of matter; usually an nal setting during which properties are changing rapidly aqueous solution.

CEMENT AND CONCRETE TERMINOLOGY 116R-25 elephant elephant trunk—an articulated tube or chute used in con- surface of concrete retards the evaporation of bleed water. crete placement. (See also dropchute and tremie.) (See also monomolecular.) elongated piece (of aggregate)—particle of aggregate for exfoliation—disintegration occurring by peeling off in suc- which the ratio of the length to the width of its circum- cessive layers, swelling up and opening into leaves or scribing rectangular prism is greater than a specified val- plates like a partly opened book. ue. (See also flat piece [of aggregate.]) exothermic reaction—see reaction, exothermic. elongation—increase in length. (See also expansion, short- expanded blast-furnace slag—see blast-furnace slag. ening, and swelling.) expanded-metal fabric reinforcement—see lath, expanded- embedment length—see length, embedment. metal. embedment-length equivalent—the length of embedded expanded-metal lath—see lath, expanded-metal. reinforcement which can develop the same stress as expanded shale (clay or slate)—see shale, expanded. that which can be developed by a hook or mechanical expanding cement—see cement, expansive. anchorage. expansion—increase in either length or volume. (See also emery—a rock consisting essentially of an intercrystalline contraction; moisture movement; shrinkage; volume mixture of corundum and either magnetite or hematite; change; and volume change, autogenous.) also manufactured aggregate composed of emery used to expansion, thermal—see thermal expansion. produce a wear-and slip-resistant concrete floor surface. expansion joint—see joint, expansion. (See also dry-shake.) expansion sleeve—see sleeve, expansion. emulsion—a colloidal dispersion of a liquid in another liquid. expansive cement—see cement, expansive. encastré—the end fixing of a built-in beam. expansive-cement concrete (mortar or grout)—see con- enclosure wall—see wall, enclosure. crete (mortar or grout) and expansive cement. encrustation—see incrustation (preferred term). expansive-cement mortar—see concrete (mortar or end anchorage—see anchorage, end. grout) and expansive cement. end-bearing sleeve—device fitting over the abutting ends of expansive component—see component, expansive. two reinforcing bars for the purpose of assuring transfer of exposed-aggregate finish—see finish, exposed-aggregate. only axial compression from one bar to the other. (See also exposed concrete—see concrete, exposed. coupler; coupling sleeve; and mechanical connection.) exposed masonry—see masonry, exposed. end block—see block, end. extender—a finely divided inert mineral added to provide endothermic reaction—see reaction, endothermic. economical bulk in paints, synthetic resins and adhesives, or other products. engineer-architect—see architect-engineer. extensibility—the maximum tensile strain that hardened ce- entrained air—see air, entrained. ment paste, mortar, or concrete can sustain before cracking entrapped air—see air, entrapped. occurs. epoxy—a thermosetting polymer that is the reaction product extension device—see device, extension. of epoxy resin and an amino hardener. (See also epoxy exterior panel—see panel, exterior. resin.) external vibrator—see vibrator. epoxy-coated bar—see bar, epoxy-coated. extreme compression fiber—see fiber, extreme com- epoxy concrete—see concrete, epoxy. pression. epoxy grout—see grout, epoxy. extreme tension fiber—see fiber, extreme tension. epoxy mortar—see mortar, epoxy. exudation—a liquid or viscous gel-like material discharged epoxy resins—see resins, epoxy. through a pore, crack, or opening in the surface of concrete. equivalent rectangular stress-distribution—an assump- tion of uniform stress on the compression side of the neu- F tral axis in the strength method of design to determine flexural capacity. fabric, welded-wire—a series of longitudinal and transverse erosion—progressive disintegration of a solid by abrasion or wires arranged approximately at right angles to each other cavitation of gases, liquids, or solids in motion. (See also and welded together at all points of intersection. abrasion damage and cavitation damage.) fabric, woven-wire—a prefabricated steel reinforcement   
    & %( ## % %(%  composed of cold-drawn steel wires mechanically twisted +,⋅1 ,⋅+",⋅ & - ,##%   % together to form hexagonally shaped openings. ($ %(#.  # #!  face, pilaster—the form for the front surface of a pilaster %#(  # '  &%# #   parallel to the wall. '  #  !      2#  $# % 3 factor—  % factor, bulking—ratio of the volume of moist sand to the evaporable water—see water, evaporable. volume of the sand when dry. evaporation retardant—a long-chain organic material such factor, coarse-aggregate—the ratio, expressed as a dec- as cetyl alcohol which when spread on a water film on the imal, of the amount (mass or solid volume) of coarse

116R-26 ACI COMMITTEE REPORT final

aggregate in a unit volume of well-proportioned con- falsework—the temporary structure erected to support work crete to the amount of dry-rodded coarse aggregate in the process of construction; composed of shoring or compacted into the same volume b/b0. vertical posting, formwork for beams and slabs, and later- factor, durability— al bracing. (See also centering.) 1. a measure of the change in a material property over fascia—a flat member or band at the surface of a building or a period of time as a response to exposure to a treat- the edge beam of a bridge; also exposed eave of a building. ment that can cause deterioration, usually expressed fastener— a device designed to attach, join, or hold two or as a percentage of the value of the property before more objects, one to another, in juxtaposition; common- exposure; or ly readily removed. 2. in ASTM C 666, a measure of the effects of freez- fat concrete—see concrete, fat. ing and thawing action on concrete specimens, in fat mortar—see mortar, fat. which resonant frequency of vibration is used as fatigue—the weakening of a material by repeated or alter- the property measured. nating loads. factor, flow—see cone, flow. fatigue failure—see failure, fatigue. factor, maturity— a factor that is a function of the age fatigue strength—see strength, fatigue. of the concrete (hours or days) multiplied by the dif- fault—differential displacement of a portion of a structure ference between the mean temperature of the concrete along a joint or crack. (degrees) during curing and a datum temperature be- feather edge—see edge, feather. low which hydration stops. (See also degree-hour.) feed, pneumatic—shotcrete delivery equipment in which factor, phi (φ)—see factor, strength-reduction (pre- material is conveyed by a pressurized air stream. ferred term). feed wheel—see wheel, feed. factor, Philleo—a distance, used as an index of the ex- felite—a name used to identify one form of the constituent of tent to which hardened cement paste is protected from portland-cement clinker now known when pure as dicalci- ⋅ the effects of freezing, so selected that only a small um silicate (2CaO SiO2). (See also alite; belite; and celite.) portion of the cement paste (usually 10%) lies farther ferrocement—a composite structural material comprising than that distance from the perimeter of the nearest air thin sections consisting of cement mortar reinforced by a void. (See also protected paste volume.) number of very closely spaced layers of steel wire mesh. factor, Powers’ spacing—see factor, spacing (pre- fiber, extreme compression—farthest fiber from the neutral ferred term.) axis on the compression side of a member subjected to factor, spacing—an index related to the maximum dis- bending. tance of any point in a cement paste or in the cement fiber, extreme tension—farthest fiber from the neutral axis paste fraction of mortar or concrete from the periphery on the tension side of a member subjected to bending of an air void; also known as Powers’ spacing factor. fiber-reinforced concrete—see concrete, fiber-reinforced. (See also factor, Philleo.) fibrous concrete—see concrete, fiber-reinforced. factor, stiffness—a measure of the stiffness of a structural field bending—bending of reinforcing bars on the job rather member; for a prismatic member, it is equal to the ratio than in a fabricating shop. of the product of the moment of inertia of the cross sec- field concrete—see concrete, field. tion and the modulus of elasticity for the material to the field-cured cylinders—see cylinders, field-cured. length of the member. field-proportioned grout—see grout, field-proportioned. factor, strength reduction—capacity-reduction factor fill, porous—see drainage fill. (in structural design); a number less than 1.0 (usually filler— 0.65 to 0.90) by which the strength of a structural 1. finely divided inert material, such as pulverized lime- member or element (in terms of load, moment, shear, stone, silica, or colloidal substances, sometimes added or stress) is required to be multiplied to determine de- to portland-cement paint or other materials to reduce sign strength or capacity; the magnitude of the factor shrinkage, improve workability, or act as an extender, is stipulated in applicable codes and construction or specifications for respective types of members and 2. material used to fill an opening in a form. cross sections. filler, joint—compressible material used to fill a joint to factor of safety—the ratio of load, moment, or shear of a prevent the infiltration of debris and provide support structural member at the ultimate to that at the service for sealants applied to the exposed surface. level. fillet—see strip, chamfer. factored load—see load, factored. fin—a narrow linear projection on a formed concrete sur- failure, fatigue—the phenomenon of rupture of a material, face, resulting from mortar flowing into spaces in the when subjected to repeated loadings, at a stress substan- formwork; also a type of blade in a concrete mixer drum. tially less than the static strength. final prestress—see stress, final. fair-face concrete—see concrete, fair-face. final set—see set, final. false header—see header. final setting time—see time, final setting. false set—see set, false. final stress—see stress, final.

CEMENT AND CONCRETE TERMINOLOGY 116R-27 fine fine aggregate—see aggregate, fine. flash coat—see coat, flash. fine-grained soil—see soil, fine-grained. flash set—see set, flash. fineness—a measure of particle size. flashing—a thin impermeable sheet, narrow in comparison fineness modulus—see modulus, fineness. with its length, installed as a cover to exclude water from finish—the texture of a surface after consolidating and fin- exposed joints, at roof valleys, hips, roof parapets, or in- ishing operations have been performed. tersections of roof and chimney. finish, bush-hammer—the finish on concrete surface flat jack—see jack, flat. obtained by means of a bush-hammer. flat piece (of aggregate)—one in which the ratio of the finish, broom—the surface texture obtained by stroking width to thickness of its circumscribing rectangular prism a broom over freshly placed concrete. (See also sur- is greater than a specified value. (See also elongated face, brushed.) piece [of aggregate.]) finish, exposed-aggregate—a decorative finish for con- flat plate—see plate, flat. crete work achieved by removing, generally before the flat slab—see slab, flat. concrete has fully hardened, the outer skin of mortar flatwork, concrete—a general term applicable to concrete and exposing the coarse aggregate. floors and slabs that require finishing operations. finish, float—a rather rough, granular concrete surface flexible joint—see joint, hinge; Mesnager; and semiflexible. texture obtained by finishing with a float. flexible pavement—see pavement, flexible. finish, granolithic—a surface layer of granolithic con- flexural bond stress—see bond, flexural stress. crete which may be laid on a base of either fresh or flexural rigidity—see rigidity, flexural. hardened concrete. flexural strength—see strength, flexural. finish, gun—undisturbed final layer of shotcrete as ap- flint—a variety of chert. (See also chert.) plied from nozzle, without hand finishing. float—a tool (not a darby), usually of wood, aluminum, or finish, rubbed—a finish obtained by using an abrasive magnesium, used in finishing operations to impart a rela- to remove surface irregularities from concrete. (See tively even but still open texture to an unformed fresh also sack rub.) concrete surface. (See also darby.) finish, rustic or washed—a type of terrazzo topping in float, angle—a finishing tool having a surface bent to which the matrix is recessed by washing before setting form a right angle; used to finish re-entrant angles. so as to expose the chips without destroying the bond float, bull—a tool comprising a large, flat, rectangular between chip and matrix; a retarder is sometimes ap- piece of wood, aluminum, or magnesium, usually 8 in. plied to the surface to facilitate this operation. (See (200 mm) wide and 42 to 60 in. (1 to 1.50 m) long, and also finish, exposed-aggregate.) a handle 4 to 16 ft (1 to 5 m) in length used to smooth finish, swirl—a nonskid texture imparted to a concrete unformed surfaces of freshly placed concrete. surface during final troweling by keeping the trowel float, devil’s—a wooden float with two nails protruding flat and using a rotary motion. from the toe, used to roughen the surface of a brown finish, trowel— the smooth or textured finish of an un- plaster coat. (See also texturing.) formed concrete surface obtained by troweling. float, power—see float, rotary (preferred term). finish coat—see coat, finish. float, rotary—a motor-driven revolving disc that smooths, finish grinding—see grinding, finish. flattens, and compacts the surface of concrete floors and finish screens—see screens, finish. floor toppings. finishing—leveling, smoothing, consolidating, and other- float finish—see finish, float. wise treating surfaces of fresh or recently placed concrete floating—the operation of finishing a fresh concrete or mor- or mortar to produce desired appearance and service. (See tar surface by use of a float, preceding troweling when also float and trowel.) that is to be the final finish. finishing machine—see machine, finishing. flow— fire clay—see clay, fire. 1. time-dependent irrecoverable deformation (see also fire resistance—see resistance, fire. creep and rheology); or fired strength—see strength, fired. 2. a measure of the consistency of freshly mixed con- fired density—see density, fired. crete, mortar, or cement paste expressed in terms of fishtail—a wedge-shaped piece of wood used as part of the the increase in diameter of a molded truncated cone support form between tapered pans in concrete joist con- specimen after jigging a specified number of times. struction. flow, capillary—flow of moisture through a capil- flange, compression—the widened portion of an I, T, or lary pore system, such as in concrete. similar cross-section beam that is shortened or com- flow, plastic—increase in the concrete strain of members pressed by bending under normal loads, such as the hori- subject to constant stress, and decrease in concrete zontal portion of the cross section of a simple span T- stress of members subject to constant strain; an obso- beam. lete term (see creep and stress relaxation). flame photometer—see photometer, flame. flow cone—see cone, flow.

116R-28 ACI COMMITTEE REPORT foundation flow factor—see cone, flow. form, edge—formwork used to limit the horizontal flow line—detectable line on a concrete wall or column usu- spread of fresh concrete on flat surfaces such as pave- ally departing somewhat from horizontal, that shows ments or floors. where the concrete in one placement has flowed horizon- form, paper—a heavy paper mold used for casting con- tally before succeeding placement has been made. crete columns and other structural shapes. flow promoter—see promoter, flow. form, permanent—any form that remains in place after flow table—see table, flow. the concrete has developed its design strength; it may flow trough—see trough, flow. or may not become an integral part of the structure. flowable consistency—see consistency, flowable. form, sliding—see slipform. flowing concrete—see concrete, flowing. form, top—form required on the upper or outer surface of fluid consistency—see consistency, fluid. a sloping slab or thin shell. fluidifier—an admixture employed in grout to decrease the form, vented—a form so constructed as to retain the solid flow factor without changing water content. (See also ad- constituents of concrete and permit the escape of water mixture, water-reducing.) and air. fluosilicate—magnesium or zinc silico-fluoride used to pre- form, wall—a retainer or mold so erected as to give the pare aqueous solutions sometimes applied to concrete as necessary shape, support, and finish to a concrete wall. surface-hardening agents. form anchor— see anchor, form. flush water—see wash (or flush) water. form coating—see coating, form. fly ash—the finely divided residue that results from the form hanger—see hanger, form. combustion of ground or powdered coal and that is trans- form insulation—see insulation, form. ported by flue gases from the combustion zone to the par- form lining—materials used to line the concreting face of ticle removal system. formwork either to impart a smooth or patterned finish to the concrete surface, to absorb moisture from the con- flying forms—see forms, flying. crete, or to apply a set-retarding chemical to the formed foam, preformed—foam produced in a foam generator pri- surface. (See also sheathing.) or to introduction of the foam into a mixer with other in- form oil—see oil, form. gredients to produce cellular concrete. (See also form paper—see paper, form. concrete, cellular.) form pressure—see pressure, form. foamed blast-furnace slag—see blast-furnace slag (2). form release agent—see agent, release. foamed concrete—see concrete, foamed. form scabbing—inadvertent removal of the surface of con- fog curing—see curing, fog. crete because of adhesion to the form. fog room—see moist room. form sealer—coating applied to the surface of a form to re- folded plate—see plate, folded. duce or prevent absorption of water from the concrete. footing—a structural element that transmits loads directly to form spacer—see spacer. (See also spreader.) the soil. form spreader—see spreader. footing, combined—a structural unit or assembly of form tie—see tie, form. units supporting more than one column. forms— footing, continuous—a combined footing of prismatic forms, flying—large prefabricated units of formwork in- or truncated shape, supporting two or more columns in corporating support, and designed to be moved from a row. place to place. footing, sloped—a footing having sloping top or side forms, ganged—prefabricated panels joined to make a faces. much larger unit (up to 30 by 50 ft [9 by 15 m]) for con- footing, stepped—a step-like support consisting of venience in erecting, stripping, and reusing; usually prisms of concrete of progressively diminishing later- braced with wales, strongbacks, or special lifting hard- al dimensions superimposed on each other to distrib- ware. ute the load of a column or wall to the subgrade. forms, moving—large prefabricated units of formwork footing, strip—see footing, continuous. incorporating supports, and designed to be moved hor- force, jacking—in prestressed concrete, the temporary izontally on rollers or similar devices with a minimum force exerted by the device which introduces tension into amount of dismantling between successive uses. the tendons. formwork—total system of support for freshly placed con- form—a temporary structure or mold for the support of con- crete including the mold or sheathing that contacts the crete while it is setting and gaining sufficient strength to concrete as well as supporting members, hardware, and be self-supporting. (See also formwork.) necessary bracing; sometimes called shuttering in the UK form, climbing—a form which is raised vertically for (See also falsework and centering.) succeeding lifts of concrete in a given structure. foundation—the structural elements through which the load form, drop-panel—a retainer or mold so erected as to of a structure is transmitted to the earth. give the necessary shape, support, and finish to a drop foundation, grid—a combined footing formed by inter- panel. secting continuous footings, loaded at the intersection

CEMENT AND CONCRETE TERMINOLOGY 116R-29 foundation

points, and covering much of the total area within the G outer limits of the assembly. foundation, mat—a continuous footing supporting an ar- ganged forms—see forms, ganged. ray of columns in several rows in each direction, hav- ganister—a highly refractory siliceous sedimentary rock ing a slab-like shape with or without depressions or used for furnace linings. openings, covering an area at least 75% of the total area gap-graded aggregate—see aggregate, gap-graded. within the outer limits of the assembly. (See also foun- gap-graded concrete—see concrete, gap-graded. dation, raft.) gas concrete—see concrete, gas. foundation, raft—a continuous slab of concrete, usually re- gauge water—see batched water (preferred term). inforced, laid over soft ground or where heavy loads gehlenite—a mineral of the melilite group, Ca2Al(AlSi)O7. must be supported to form a foundation. (See also foun- (See also akermanite; melilite; merwinite.) dation, mat.) gel—matter in a colloidal state that does not dissolve, but re- foundation, strip—a continuous foundation wherein the mains suspended in a solvent from which it fails to precip- length considerably exceeds the breadth. itate without the intervention of heat or of an electrolyte. foundation bolt—see bolt, anchor (preferred term). (See also gel, cement.) four-way reinforcement—see reinforcement, four-way. gel, cement— the colloidal material that makes up the fracture—a crack or break, as of concrete or masonry; the major portion of the porous mass of which mature hy- configuration of a broken surface; also the action of crack- drated cement paste is composed. ing or breaking. (See also crack.) gel, tobermorite—the binder of concrete cured moist or in frame, rigid—a frame depending on moment in joints for atmospheric-pressure steam; a lime-rich gel-like solid stability. containing 1.5 to 1.0 mols of lime per mol of silica. free fall—descent of freshly mixed concrete into forms with- Gillmore needle—see needle, Gillmore. out dropchutes or other means of confinement; also the girder—a large beam, usually horizontal, that serves as a distance through which such descent occurs; also uncon- main structural member. trolled fall of aggregate. girt—small beam spanning between columns, generally free lime—see lime, free. used in industrial buildings to support outside walls. (See free moisture—see moisture, free. also beam.) free water—see moisture, free. (See also moisture, surface.) glass—an inorganic product of fusion that has cooled too a fresh concrete—see concrete, fresh. rigid condition without crystallizing, sometimes reactive fresno trowel—a thin steel trowel that is rectangular or rect- with alkalies in concrete. angular with rounded corners, usually 4 to 10 in. (100 to glass-fiber reinforced cement—a composite material con- 250 mm) wide and 20 to 36 in. (420 to 900 mm) long, hav- sisting essentially of a matrix of hydraulic cement paste or ing 4 to 16 ft (1 to 5 m) long handle, and used to smooth mortar reinforced with glass fibers; typically precast into surfaces of nonbleeding concrete and shotcrete. units less than 1 in. (25 mm) thick. friction loss—see loss, friction. friction pile—see pile, friction. glass-transition temperature—see temperature, glass- transition. friction, wobble—in prestressed concrete, the friction caused by the unintended deviation of the prestressing go-devil—a ball of rolled-up burlap or paper or a specially sheath or duct from its specified profile. fabricated device put into the pump end of a pipeline and frog—a depression in the bed surface of a masonry unit; forced through the pipe by water pressure in order to clean sometimes called a panel. the pipeline; also a device used with tremie concrete op- fugitive dye—a dye whose color fades in a few days to neu- erations. tral on exposure, usually to ultraviolet rays in sunlight; grab set—see set, flash (preferred term). used to temporarily color membrane-curing compounds gradation—see grading (preferred term). so that coverage of the concrete surface can be observed. grade—the prepared surface on which a concrete slab is Fuller-Thompson ideal grading curve—see Fuller’s cast; the process of preparing a plane surface of granular curve (preferred term). material or soil on which to cast a concrete slab. Fuller’s curve—an empirical curve for gradation of aggre- grade beam—see beam, grade. gates; also known as the Fuller-Thompson ideal gradation grade strip—see strip, grade. curve; the curve is designed by fitting either a parabola or graded standard sand—see sand, standard. an ellipse to a tangent at the point where the aggregate gradient—rate of change in a variable over a distance, as of fraction is one-tenth of the maximum size fraction. (See temperature or moisture. also grading curve.) grading—the distribution of particles of granular material furring—strips of wood or metal fastened to a wall or other among various sizes; usually expressed in terms of cumu- surface to even it, to form an air space, to give appearance lative percentages larger or smaller than each of a series of greater thickness, or for the application of an interior of sizes (sieve openings) or the percentages between cer- finish such as plaster. tain ranges of sizes (sieve openings).

116R-30 ACI COMMITTEE REPORT grouting grading, combined-aggregate—particle-size distribution a mixture of other composition but of similar consistency. of a mixture of fine and coarse aggregate. (See also grout, neat cement and grout, sanded.) grading, continuous—a particle size distribution in which grout, colloidal—grout in which a substantial proportion intermediate size fractions are present, as opposed to gap- of the solid particles have the size range of a colloid. grading. (See also aggregate, gap-graded.) grout, epoxy—a grout that is a mixture of ingredients grading curve—see curve, grading. consisting of an epoxy bonding system, aggregate or granolithic concrete—see concrete, granolithic. fillers, and possibly other materials. granolithic finish—see finish, granolithic. grout, expansive-cement—see concrete (mortar or granulated blast-furnace slag—see blast-furnace slag. grout) and expansive-cement. gravel— grout, field-proportioned—a hydraulic-cement grout 1. granular material predominantly retained on the 4.75 batched at the jobsite using water and predetermined mm (No. 4) sieve and resulting either from natural dis- portions of portland cement, aggregate, and other in- integration and abrasion of rock or processing of gredients. weakly bound conglomerate; and grout, hydraulic-cement—a grout which is a mixture of 2. that portion of an aggregate retained on the 4.75 mm hydraulic cement, aggregate, water and possibly ad- (No. 4) sieve and resulting either from natural disinte- mixtures. gration and abrasion of rock or processing of weakly grout, machine-base—a grout which is used in the space bound conglomerate. (See also aggregate, coarse.) between plates or machinery and the underlying foun- gravel, crushed—the product resulting from the artifi- dation and which is expected to maintain essentially cial crushing of gravel with a specified minimum per- complete contact with the base and to maintain uni- centage of fragments having one or more faces form support. resulting from fracture. (See also aggregate, coarse.) grout, masonry—a mixture of hydraulic cement, aggre- gravel, pea— screened gravel, most of the particles of gate, water and possibly other materials (ASTM C which pass a 9.5 mm (3/8 in.) sieve and are retained on 476), used for filling designated spaces in masonry a 4.75 mm (No. 4) sieve. construction. green concrete—see concrete, green. grout, neat cement—a fluid mixture of hydraulic cement grid foundation—see foundation, grid. and water, with or without other ingredients; also the grinding, finish—the final grinding of clinker into cement, hardened equivalent of such mixture. with calcium sulfate in the form of gypsum or anhydrite grout, preblended—a hydraulic-cement grout which is a generally being added; the final grinding operation re- commercially available mixture of hydraulic cement, quired for a finished concrete surface, for example, bump aggregate, and other ingredients, which requires only cutting of pavement, fin removal from structural con- the addition of water and mixing at the jobsite; some- crete, and terrazzo floor grinding. time termed premixed grout. grinding aids—see aids, grinding. grout, sanded—grout in which fine aggregate is incorpo- grinding medium—see medium, grinding. rated into the mixture. grizzly—a simple, stationary screen or series of equally grout slope—the natural slope of fluid grout injected into spaced parallel bars set at an angle to remove oversized preplaced-aggregate concrete. particles in processing aggregate or other material. grouted-aggregate concrete—see concrete, preplaced-ag- grog—burned refractory material; usually calcined clay or gregate. crushed brick bats. grouted masonry—see masonry, grouted. groove joint—see joint, contraction (preferred term). grouting—the process of filling with grout. (See also grout.) groover—a tool used to form grooves or weakened-plane grouting, advancing-slope—a method of grouting by joints in a concrete slab before hardening to control crack which the front of a mass of grout is caused to move location or provide pattern. horizontally through preplaced aggregate by use of a gross vehicle load—the mass of a vehicle plus the mass of suitable grout injection sequence. any load thereon. grouting, closed-circuit—injection of grout into a hole in- gross volume (of concrete mixers)—in the case of a revolv- tersecting fissures or voids that are to be filled at such ing-drum mixer, the total interior volume of the revolving volume and pressure that grout input to the hole is great- portion of the mixer drum; in the case of an open-top mix- er than the grout take of the surrounding formation, ex- er, the total volume of the trough or pan calculated on the cess grout being returned to the pumping plant for basis that no vertical dimension of the container exceeds recirculation. twice the radius of the circular section below the axis of grouting, containment—see grouting, perimeter. the central shaft. grouting, contraction-joint—injection of grout into con- ground-granulated slag—see blast-furnace slag. traction joints. ground wire—see wire, ground. grouting, control-joint—see grouting, contraction- grout—a mixture of cementitious material and water, with joint. or without aggregate, proportioned to produce a pourable grouting, curtain—injection of grout into a subsurface consistency without segregation of the constituents; also formation in such a way as to create a zone of grouted

CEMENT AND CONCRETE TERMINOLOGY 116R-31 grouting

material transverse to the direction of anticipated water H flow. grouting, high-lift—a technique in masonry wall con- hacking—the roughening of a surface by striking with a struction in which the grouting operation is delayed un- tool. til the wall has been laid up to a full story height. hairline cracks—see cracks, hairline. grouting, low-lift—a technique of masonry wall con- hairpin—the wedge used to tighten some types of form ties; struction in which the wall sections are built to a height a hairpin-shaped anchor set in place while concrete is un- of not more than 5 ft (1.7 m) before the cells of the ma- hardened; a light hairpin-shaped reinforcing bar used for sonry units are filled with grout. shear reinforcement in beams, tie reinforcement in col- grouting, open-circuit—a grouting system with no pro- umns, or prefabricated column shear heads. vision for recirculation of grout to the pump. Hamm tip—flared shotcrete nozzle having a larger diameter grouting, perimeter—injection of grout, usually at rela- at midpoint than at either inlet or outlet; also designated tively low pressure, around the periphery of an area premixing tip. that is subsequently to be grouted at greater pressure; hammer— intended to confine subsequent grout injection within hammer, impact—see hammer, rebound (preferred the perimeter. term). grouting, slush—distribution of grout, with or without hammer, rebound—an apparatus that provides a relative fine aggregate, as required over a rock or concrete sur- indication of the strength or hardness of concrete based face that is subsequently to be covered with concrete, on the rebound distance of a spring-driven mass after usually by brooming it into place to fill surface voids it impacts a rod in contact with the concrete surface. and fissures. hammer, Schmidt—see hammer, rebound (preferred grouting, staged—sequential grouting of a hole in sepa- term). rate steps or stages in lieu of grouting the entire length hammer, Swiss—see hammer, rebound (preferred term). at once. hanger—a device used to suspend one object from another object such as the hardware attached to a building frame gun— to support forms. (See also beam hanger.) 1. shotcrete material delivery equipment, usually con- hanger, form—device used to support formwork from a struc- sisting of double chambers under pressure; equipment tural framework; the dead load of forms, mass of concrete, with a single pressure chamber is used to some extent and construction and impact loads must be supported. (see also gun, cement); or hard-burned dolomite—see dolomite, hard-burned. 2. pressure cylinder used to propel freshly mixed con- hard-burned lime—see lime, hard-burned. crete pneumatically. hardened concrete—see concrete, hardened. gun, cement—a machine for pneumatic placement of hardener— mortar or small aggregate concrete; in the “Dry Gun,” 1. a chemical (including certain fluosilicates or sodium water from a separate hose meets the dry material at silicate) applied to concrete floors to reduce wear and the nozzle of the gun; with the “Wet Gun,” the deliv- dusting; or ery hose conveys the premixed mortar or concrete. 2. in a two-component adhesive or coating, the chemical (See also shotcrete.) component that causes the resin component to cure. gun finish—see finish, gun. Hardy Cross method—see moment distribution. Gunite—a proprietary term for shotcrete. harped tendons—see tendons, deflected (preferred term). gunman—workman on shotcreting crew who operates de- harsh mixture—see mixture, harsh. livery equipment. haunch—a deepened portion of a beam in the vicinity of a gunning—act of applying shotcrete; ejection of material support. from nozzle and impingement on surface to be gunned. haunching— gunning pattern— 1. concrete support to the sides of a drain or sewer pipe 1. conical outline of material discharge stream in shot- above the bedding; or crete operation; or 2. work done in strengthening or improving the outer 2. the sequence of gunning operations to ensure com- strip of a roadway. plete filling of the space, total encasement of reinforc- hawk—a tool used by plasterers to hold and carry plaster ing bars, easy removal of rebound, and thickness of mortar; generally a flat piece of wood or metal approxi- shotcrete layers. mately 10 to 12 in. (0.25 to 0.3 m) square, with a wooden gutter tool—see tool, gutter. handle centered and fixed to the underside. (See also hod  
    #   ## % %( and mortar board.)  +",⋅ - , header—a masonry unit laid flat with its greatest dimension gypsum concrete—see concrete, gypsum. at a right angle to the face of the wall; when the unit is gypsum plaster—plaster made with plaster of paris. (See only the depth of the face wythe it is known as a false plaster and plaster of paris.) header. (See also bonder and wythe [leaf.])

116R-32 ACI COMMITTEE REPORT hydrophobic header, false—see header. hinge, Mesnager—a permanent semiarticulation or flexible healing, autogenous—a natural process of filling and seal- joint in a reinforced concrete arch, wherein the angles of ro- ing cracks in concrete or in mortar when kept damp. tation at the hinge are very small; by crossing steel reinforc- heat-deflection temperature—see temperature, heat-de- ing bars within the opening between the concrete structural flection. segments, the resultant articulation presents very small re- heat of hydration—heat evolved by chemical reactions sistance to rotation, resists either axial thrust or shearing with water, such as that evolved during the setting and forces, and is permanently flexible; the center of rotation hardening of portland cement, or the difference between occurs at the intersection of the reinforcing bars. the heat of solution of dry cement and that of partially hy- hinge, plastic—region where ultimate moment capacity in a drated cement. (See also heat of solution.) member may be developed and maintained with corre- heat of solution—heat evolved or absorbed when a sub- sponding significant inelastic rotation as main tensile stance is dissolved in a solvent. steel elongates beyond yield strain. heat-resistant concrete—see concrete, heat resistant. hinge joint—see joint, hinge. heating rate—the rate expressed in degrees per hour at hod—a V-shaped trough or a tray, supported by a pole han- which the temperature is raised to the desired maximum dle that is borne on the carrier’s shoulder, for carrying temperature. small quantities of brick, tile, mortar, or similar load. (See heavy concrete—see concrete, high-density (preferred also hawk and mortar board.) term). hold-down bolt—see bolt, anchor (preferred term). heavy-edge reinforcement—see reinforcement, heavy- holding period—see period, presteaming (preferred term). edge. hollow-unit masonry—see masonry, hollow-unit. heavy-media separation—see separation, heavy-media. honeycomb—voids left in concrete due to failure of the heavyweight aggregate—see concrete, high-density (pre- mortar to effectively fill the spaces among coarse-aggre- ferred term). gate particles. heavyweight concrete—see concrete, high-density. hook—a bend in the end of a reinforcing bar. helical reinforcement—see reinforcement, helical. hooked bar—see bar, hooked. hematite—a mineral, iron oxide (Fe2O3), used as aggregate Hooke’s law—see law, Hooke’s. in high density concrete and in finely divided form as a hoop reinforcement—see reinforcement, hoop. red pigment in colored concrete. horizontal-axis mixer—see mixer, horizontal-axis. hemihydrate—a hydrate containing one-half molecule of horizontal-shaft mixer—see mixer, horizontal-shaft. water to one molecule of compound; the most commonly horizontal shoring—see shoring, horizontal. known hemihydrate is partially dehydrated gypsum (also hose, delivery—hose through which shotcrete, grout, or ⋅ known as plaster of paris), CaSO4 1/2H2O. (See also bas- pumped concrete or mortar passes; also known as convey- sanite.) ing hose or material hose.  
   
 
 ( hot cement—see cement, hot. Hessian—see burlap (preferred term). hot face—the surface of a refractory section exposed to the high-alumina cement—see cement, calcium-aluminate source of heat. (preferred term). hot-load test—see test, hot-load. high-bond bar—see bar, deformed. Hoyer effect—in pretensioned, prestressed concrete, fric- high-density concrete—see concrete, high-density. tional forces that result from the tendency of the tendons high-discharge mixer—see mixer, inclined-axis (pre- to regain the diameter which they had before they were ferred term). stressed. high-early-strength cement—see cement, high-early- hydrate—a chemical combination of water with another strength. compound or element. high-fineness cement—see cement, high-fineness. hydrate, calcium-silicate—any of the various reaction high-early-strength concrete—see concrete, high-early- products of calcium silicate and water. (See also dicalci- strength. um silicate and tricalcium silicate.) high-lift grouting—see grouting, high-lift. hydrated lime—see lime, hydrated. high-performance concrete—see concrete, high-perfor- hydration—formation of a compound by the combining of mance. water with some other substance; in concrete, the chemi- high-pressure steam curing—see curing, autoclave (pre- cal reaction between hydraulic cement and water. ferred term). hydraulic cement—see cement, hydraulic. high-range water-reducing admixture—see admixture, hydraulic-cement grout—see grout, hydraulic-cement. water-reducing (high-range). hydraulic hydrated lime—see lime, hydraulic hydrated. high-strength concrete—see concrete, high-strength. hydrochloric acid—a mineral acid sometimes used for high-strength reinforcement—see steel, high-strength. cleaning or acid etching concrete or removing efflores- high-strength steel—see steel, high-strength. cence; also known as muriatic acid, which is a 33% HCl high-temperature steam curing—see curing, atmospheric- solution. pressure steam and curing, autoclave. hydrophobic cement—see cement, hydrophobic.

CEMENT AND CONCRETE TERMINOLOGY 116R-33 hydrous hydrous calcium chloride—see calcium chloride, hydrous. internal vibration—see vibration. inverted L-beam—a beam having a cross section in the I shape of an inverted L. (See also L-beam.) inverted T-beam—a beam having a cross section in the ignition loss—see loss on ignition (preferred term). shape of an inverted T. (See also T-beam.) ilmenite—a mineral, iron titanate (FeTiO3), which in pure or I-section—beam cross section consisting of top and bottom impure form is commonly used as aggregate in high-den- flanges connected by a vertical web. sity concrete. isolation joint—see joint, isolation. impact hammer—see hammer, rebound (preferred term). isotropy—the behavior of a medium having the same prop- impending slough—a consistency of a shotcrete mixture erties in all directions. containing the maximum amount of water so that the product will not flow or sag after placement. J inclined-axis mixer—see mixer, inclined-axis. incrustation—a crust or coating, generally hard, formed on jack—a mechanical device used for applying force to pre- the surface of concrete or masonry construction or on ag- stressing tendons, for adjusting elevation of forms or form gregate particles. supports, and for raising objects small distances. indented strand—see strand, indented. jack, flat—a hydraulic jack consisting of light gage metal indented wire—see wire, indented. that is folded and welded to a flat shape that expands index, plasticity—the range in water content through which a under internal pressure. soil remains plastic; numerical difference between the liq- jack shore—telescoping, or otherwise adjustable, single- uid limit and the plastic limit. (See also limits, Atterberg.) post metal shore. index, pozzolanic-activity—an index that measures poz- jacking device—the device used to stress the tendons for zolanic activity based on the strength of cementitious prestressed concrete; also the device for raising a vertical mixtures containing hydraulic cement with and without slipform. the pozzolan; or containing the pozzolan with lime. jacking force—see force, jacking. industrialized building—the integration of planning, de- sign, programming, manufacturing, site operations, jacking stress—see stress, jacking. scheduling, financing, and management into a disciplined jaw crusher—a machine having two inclined jaws, one or method of mechanized production of buildings, some- both being actuated by a reciprocating motion so that the times called systems building. charge is repeatedly nipped between the jaws. inelastic behavior—see deformation, inelastic (preferred jet, air-water—a high-velocity jet of air and water mixed at term). the nozzle, used in clean-up of surfaces of rock or con- inelastic deformation—see deformation, inelastic. crete, such as horizontal construction joints. infrared spectroscopy—see spectroscopy, infrared. jitterbug—a grate tamper for pushing coarse aggregate initial drying shrinkage—see shrinkage, initial drying. slightly below the surface of a slab to facilitate finishing. initial prestress—see prestress, initial. (See also tamper.) initial set—see set, initial. joint—a physical separation in a concrete system, whether initial setting time—see time, initial setting. precast or cast-in-place, including cracks if intentionally initial stresses—see stresses, initial. made to occur at specified locations; also the region initial-tangent modulus—see modulus of elasticity. where structural members intersect, such as a beam-col- insert—anything other than reinforcing steel that is rigidly umn joint. positioned within a concrete form for permanent embed- joint, butt—a plain square joint between two members. ment in the hardened concrete. joint, cold—a joint or discontinuity resulting from a de- in-situ concrete—see concrete, cast-in-place (preferred lay in placement of sufficient duration to preclude in- term). termingling and bonding of the material in two insoluble residue—the portion of a cement or aggregate that successive lifts of concrete, mortar, or the like. is not soluble in dilute hydrochloric acid of stated concen- joint, construction—the surface where two successive tration. placements of concrete meet, across which it may be de- insulating concrete—see concrete, insulating. sirable to achieve bond and through which reinforce- insulation, form—insulating material applied to the outside ment may be continuous. of forms between studs and over the top in sufficient joint, contraction—formed, sawed, or tooled groove in a thickness and air tightness to conserve heat of hydration concrete structure to create a weakened plane to regu- to maintain concrete at required temperatures in cold late the location of cracking resulting from the dimen- weather. sional change of different parts of the structure. (See insulation, roof— low-density concrete used for insulating also joint, isolation; joint, expansion; and joint, con- purposes only and placed over a structural roof system. struction.) intermittent sampling—see sampling, intermittent. joint, control—see joint, contraction (preferred term).

116R-34 ACI COMMITTEE REPORT kiln

joint, cross—the joint at the end of individual form- to cut a joint partly through fresh concrete. (See also boards between subpurlins. jointing.) joint, expansion— jointing—the process of producing joints in a concrete slab. 1. a separation provided between adjoining parts of a (See also jointer [concrete].) structure to allow movement where expansion is joist—a comparatively narrow beam used in closely spaced likely to exceed contraction; or arrangements to support floor or roof slabs (that require 2. a separation between pavement slabs on grade, no reinforcement except that required for temperature and filled with a compressible filler material; or shrinkage stresses); also a horizontal structural member 3. an isolation joint intended to allow independent such as that which supports deck form sheathing. (See movement between adjoining parts. also beam.) joint, flexible—see joint; hinge; joint, Mesnager; jumbo—traveling support for forms, commonly used in tun- and joint, semiflexible. nel work. joint, groove—see joint, contraction (preferred term). joint, hinge—any joint which permits rotation with no K appreciable moment developed in the members at the joint. (See also joint, hinge; joint, Mesnager; and kaolin—a rock, generally white, consisting primarily of clay joint, semiflexible.) minerals of the kaolinite group, composed principally of joint, isolation—a separation between adjoining parts of hydrous aluminum silicate of low iron content, used as a concrete structure, usually a vertical plane, at a de- raw material in the manufacture of white cement. signed location such as to interfere least with perfor- kaolinite—a common clay mineral having the general for- mance of the structure, yet such as to allow relative mula Al2(Si2O5)(OH4), the primary constituent of kaolin. movement in three directions and avoid formation of Keene’s cement—see cement, Keene’s. cracks elsewhere in the concrete and through which all Kelly ball—an apparatus used for indicating the consistency or part of the bonded reinforcement is interrupted. of fresh concrete, consisting of a cylindrical weight 6 in. (See also joint, contraction and joint, expansion.) (150 mm) in diameter, weighing 30 lb (14 kg) with a joint, lift—surface at which two successive lifts meet. hemispherically shaped bottom, a handle consisting of a joint, longitudinal—a joint parallel to the length of a graduated rod, and a stirrup to guide the handle and serve structure or pavement. as a reference for measuring depth of penetration. (See joint, raked—a masonry-wall joint that has the mortar also test, ball.) raked out to a specified depth while it is only slightly Kelly ball test—see test, ball and Kelly ball. hardened. kerb form; kerb tool—see curb form and curb tool (pre- joint, sawed—a joint cut in hardened concrete, generally ferred terms in the U.S.; kerb is used in the UK). not to the full depth of the member, by means of spe- kerf—cut or notch, as a beam, transversely along the under- cial equipment. side to curve it; also a cut or notch in a member, such as a joint, scarf—see connection, scarf. rustication strip, to avoid damage from swelling of the joint, semiflexible—a connection in which the reinforce- wood and permit easier removal. ment is arranged to permit some rotation of the joint. kern area—the area within a geometric shape in which a (See also joint, hinge and Mesnager, joint.) compressive force may be applied without tensile stresses joint, separation—see joint, isolation (preferred term). resulting in any of the extreme fibers of the section. joint, transverse—a joint normal to the longitudinal di- kern distance—the distance from the centroid of a section mension of a structural element, assembly of ele- to the farthest point from the centroid at which a resultant ments, slab, or structure. force can act without inducing a stress of opposite sign at joint, warping— a joint with the sole function of permit- the extreme fiber on the opposite side of the centroid. ting warping of pavement slabs when moisture and key—see keyway. temperature differentials occur between the top and keyed—fastened or fixed in position in a notch or other recess. bottom of the slabs, that is, longitudinal or transverse keyway—a recess or groove in one lift or placement of con- joints with bonded steel or tie bars passing through crete that is filled with concrete of the next lift, giving them. shear strength to the joint. (See also tongue and groove.) joint, weakened-plane—see joint, groove and joint, kick strip—see kicker (preferred term). contraction (preferred term). kicker—a wood block or board attached to a formwork joint filler—see filler, joint. member in a building frame or formwork to make the joint sealant—see sealant, joint. structure more stable; in formwork it acts as a haunch. joint-sealing compound—see compound, joint-sealing. (See also wall, stub.) joint spall—a spall adjacent to a joint. kiln—a furnace or oven for drying, charring, hardening, bak- jointer (concrete)—a metal tool approximately 6 in. (150 ing, calcining, sintering, or burning various materials. mm) long and from 2 to 4-1/2 in. (50 to 100 mm) wide (See also steam-curing room.) and having shallow, medium, or deep bits (cutting edges) kiln, cement—a kiln in which the ground and propor- ranging from 3/16 to 3/4 in. (5 to 20 mm) or deeper used tioned raw mixture is dried, calcined, and burned into

CEMENT AND CONCRETE TERMINOLOGY 116R-35 kiln

clinker at a temperature of 2600 to 3000 F (1420 to layer, bonding—a layer of mortar, usually 1/8 to 1/2 in. (3 1650 C); can be of the rotary, shaft, fluid-bed, or trav- to 13 mm) thick, which is spread on a moist and prepared, eling-grate type; fuel may be coal, oil, or gas. hardened concrete surface before placing fresh concrete. kiln, rotary—a long steel cylinder with a refractory lin- L-beam—a beam having a cross section in the shape of an ing, supported on rollers so that it can rotate about its L; a beam having a ledge on one side only. own axis, and erected with a slight inclination from the L-column—the portion of a precast concrete frame compris- horizontal so that prepared raw materials fed into the ing the column, the haunch, and part of the girder. higher end move to the lower end where fuel is blown leaf—see wythe (leaf). in by air blast. lean concrete—see concrete, lean. kiln, steam—see steam-curing room (preferred term). lean mixture—see concrete, lean. kip—1000 lb force, equals 4448 N. lean mortar—see mortar, lean. ledger—any member with a protrusion or protrusions that knee brace—brace between horizontal and vertical mem- support other structural members. (See also L-beam and bers in a building frame or formwork to make the struc- inverted T-beam.) ture more stable; in formwork it acts as a haunch. length— length, development—the embedment length required to L develop the design strength of a reinforcement at a crit- ical section; formerly called bond length. lacing—horizontal bracing between shoring members. length, embedment—the length of embedded reinforce- lagging—heavy sheathing used as in underground work to ment provided beyond a critical section. withstand earth pressure. (See also sheathing.) length, transfer—the length from the end of the member laitance—a layer of weak material derived from cementi- where the tendon stress is zero, to the point along the tious material and aggregate fines either: 1) carried by tendon where the prestress is fully effective; also bleeding to the surface or to internal cavities of freshly called transmission length. placed concrete; or 2) separated from the concrete and de- length, transmission—see length, transfer. posited on the concrete surface or internal cavities during length change—increase or decrease in length. (See also placement of concrete underwater. volume change and deformation.) lap—the length by which one bar or sheet of fabric reinforce- length change, autogenous—length change caused by au- ment overlaps another. togenous volume change. (See volume change, autoge- lap splice—see splice, lap. nous.) lapping (reinforcing steel)—the overlapping of reinforcing lever arm—in a structural member, the distance from the steel bars, welded-wire fabric, or expanded metal so that center of the tensile reinforcement to the center of action there may be continuity of stress in the reinforcing when of the compression zone; also the perpendicular distance the concrete member is subjected to loading. of a transverse force from a point about which moment is taken. larnite—a mineral, beta dicalcium silicate (Ca2SiO4); occurs naturally at Scawt Hill, Northern Ireland, and artificially in L-head—the top of a shore formed with a braced horizontal slags and as a major constituent of portland cement. member projecting from one side, producing an inverted L-shaped assembly. lateral reinforcement—see reinforcement, lateral. lift—the concrete placed between two consecutive horizon- latex—a water emulsion of a high molecular-weight poly- tal construction joints, usually consisting of several layers mer, used especially in coatings, adhesives, leveling com- or courses. pounds, and patching compounds. lift joint—see joint, lift. lath, expanded-metal—a metal network, often used as re- lift slab—a method of concrete construction in which floor inforcement in concrete or mortar construction, formed and roof slabs are cast on or at ground level and hoisted by suitably stamping or cutting sheet metal and stretch- into position by jacking; also a slab that is a component of ing in to form open meshes, usually of diamond shape. such construction. (See also mesh, diamond.) lifts (or tiers)—the number of frames of scaffolding erected law, Abrams’—a rule stating that, with given concrete one above the other. materials and conditions of test, the ratio of the amount lightweight aggregate—see aggregate, lightweight. of water to the amount of the cement in the mixture deter- lightweight concrete—see concrete, lightweight. mines the strength of the concrete provided the mixture is lime—specifically, calcium oxide (CaO); loosely, a general of a workable consistency. (See also water-cement ratio.) term for the various chemical and physical forms of law, Hooke’s—the law, which holds practically for strains quicklime, hydrated lime, and hydraulic hydrated lime. within the elastic limit, that the strain is proportional to the (See also lime, hydrated; lime, hydraulic hydrated; stress producing it. (See also limit, proportional and and quicklime.) modulus of elasticity.) lime, free—calcium oxide (CaO), as in clinker and ce- layer—see course and lift. ment, which has not combined with SiO2, Al2O3, or

116R-36 ACI COMMITTEE REPORT load

Fe2O3 during the burning process usually because of prestressed structure by changing the location of the ten- underburning, insufficient grinding of the raw mix- don at one or more interior supports without altering its ture, or the presence of traces of inhibitors. position at the end supports and without changing the ba- lime, hard-burned—the product of heating limestone to sic shape of the path between any supports; linear trans- temperatures sufficient to change the calcium carbon- formation does not change the location of the path of the ate to calcium oxide, which can undergo expansion pressure line. when it slowly reacts with water. linear-traverse method—determination of the volumetric lime, hydrated—calcium hydroxide, a dry powder ob- composition of a solid by integrating the distance tra- tained by treating quicklime with water. versed across areas of each component along a line or lime, hydraulic hydrated—the hydrated dry cementi- along regularly spaced lines in one or more planes inter- tious product obtained by calcining a limestone con- secting a sample of the solid; frequently employed to de- taining silica and alumina to a temperature short of termine characteristics of the air-void system in hardened incipient fusion so as to form sufficient free calcium concrete by microscopical examination along a series of oxide to permit hydration and at the same time leaving traverse lines on finely ground sections of the concrete; unhydrated sufficient calcium silicates to give the dry sometimes called the Rosiwal method. (See also point powder its hydraulic properties. count method and point count method [modified].)   

  ( %# (      lining—any sheet, plate, or layer of material attached direct- 4(  #  µ   ly to the inside face of formwork to improve or alter the limestone—a sedimentary rock consisting primarily of cal- surface texture and quality of the finished concrete. (See cium carbonate. also form lining, tunnel lining, and sheathing.) limit— lintel—a horizontal supporting member above an opening, limit, elastic—the limit of stress beyond which the strain such as a window or a door. is not wholly recoverable. liquid limit—see limit, liquid. limit, liquid—water content, expressed as a percentage liquid-volume measurement—measurement of grout on the of the dry weight of the soil at which the soil passes basis of the total volume of solid and liquid constituents. from the plastic to the liquid state under standard test conditions. (See also limits, Atterberg.) lithology—the study of rocks. (See also petrography and limit, plastic—the water content at which a soil will just petrology.) begin to crumble when rolled into a thread approxi- live load—see load, live. mately 1/8 in. (3 mm) in diameter. (See also limits, load— Atterberg.) load, allowable—see load, service dead and load, ser- limit, proportional—the greatest stress that a material is vice live. capable of developing without any deviation from pro- load, axle—the portion of the gross weight of a vehicle portionality of stress to strain. (See also law, transmitted to a structure or a roadway through wheels Hooke’s.) supporting a given axle. limit, shrinkage—the maximum water content at which a load, balanced—load capacity at simultaneous compres- reduction in water content will not cause a decrease in sive failure of concrete and yielding of tension steel. volume of the soil mass. (See also limits, Atterberg.) (See also load balancing.) limit, vibration—the age at which fresh concrete has load, cracking—the load that causes tensile stress in a hardened sufficiently to prevent its becoming mobile member to exceed the tensile strength of the concrete. when subjected to vibration. load, dead—a constant load that in structures is due to the limits, Atterberg—arbitrary water contents (shrinkage lim- mass of the members, the supported structure, and per- it, plastic limit, liquid limit) determined by standard tests manent attachments or accessories. that define the boundaries between the different states of load, design—obsolete term for factored load. consistency of plastic soils. load, dynamic— a load that is variable, that is, not static, limit design—a method of proportioning reinforced-con- such as a moving live load, earthquake, or wind. crete members based on calculation of their strength. (See also strength-design method.) load, factored—load, multiplied by appropriate load fac- limonite—an iron ore composed of a mixture of hydrated tors, used to proportion members by the strength-de- ferric oxides; occasionally used in heavyweight concrete sign method. because of its high density and combined-water content, load, live—any load that is not permanently applied to a which contribute to its effectiveness in radiation shield- structure; transitory load. ing; a mineral occurring commonly as a constituent of load, point—a load whose area of contact with the resist- particles of natural aggregate. (See also oxide, brown.) ing body is negligible in comparison with the area of linear prestressing—prestressing applied to linear mem- the resting body. bers, such as beams and columns. load, safe leg—the load that can safely be directly im- linear transformation—the method of altering the path of posed on the frame leg of a scaffold. (See also load, the prestressing tendon in any statically indeterminate service.)

CEMENT AND CONCRETE TERMINOLOGY 116R-37 load

load, service—all loads, static or transitory, imposed on a longitudinal bar—see reinforcement, longitudinal (pre- structure, or element thereof, during operation of a fa- ferred term). cility. longitudinal crack—see crack, longitudinal. load, service dead—the dead weight supported by a longitudinal joint—see joint, longitudinal. member. longitudinal reinforcement—see reinforcement, longitu- load, service live—the live load specified by the general dinal. building code or other bridge specification, or the actu- Los Angeles abrasion test—see test, Los Angeles abra- al nonpermanent load applied in service. sion. load, shock—impact of material, such as aggregate or loss— concrete, as it is released or dumped during placement. loss, anchorage—see deformation, anchorage or slip. load, static—the mass of a single stationary body or the loss, elastic—in prestressed concrete, the reduction in combined masses of stationary bodies in a structure prestressing load resulting from the elastic shortening (such as the load of a stationary vehicle on a roadway); of the member. or, during construction, the combined mass of forms, loss, friction—the stress loss in a prestressing tendon re- stringers, joists, reinforcing bars, and the actual con- sulting from friction between the tendon and duct or crete to be placed. (See also load, dead.) other device during stressing. load, superimposed—the load, other than its own weight, loss, ignition—see loss on ignition (preferred term). that is resisted by a structural member or system. loss, plastic—see creep. load, ultimate—the maximum load that may be placed on loss, shrinkage—reduction of stress in prestressing steel a structure or structural element before its failure. resulting from shrinkage of concrete. load, wheel—the portion of the gross mass of a loaded ve- loss, slump—the amount by which the slump of freshly hicle transferred to the supporting structure under a mixed concrete changes during a period of time after given wheel of the vehicle. an initial slump test was made on a sample or samples load, working—forces normally imposed on a member in thereof. service (obsolete term). loss of prestress—the reduction in the prestressing force load balancing—a technique used in the design of pre- which results from the combined effects of slip at anchor- stressed-concrete members in which the amount and path age, relaxation of steel stress, frictional loss due to curva- of the prestressing is selected so that the forces imposed ture in the tendons, and the effects of elastic shortening, upon the member or structure by the prestressing counter- creep, and shrinkage of the concrete. act or balance a portion of the dead and live loads for loss on ignition—the percentage loss in mass of a sample ig- which the member or structure must be designed. nited to constant weight at a specified temperature, usual- ly 1650 to 1830 F (900 to 1000 C). load binder—a device used to tighten chains holding loads lot—a defined quantity, usually merchandise. in place on a truck bed. low-alkali cement—see cement, low-alkali. load factor—a factor by which a service load is multiplied low-density concrete—see concrete, low-density and con- to determine a factored load used in the strength-design crete, lightweight. method. low-heat cement—see cement, low heat. load-bearing wall—see wall, load-bearing. low-lift grouting—see grouting, low-lift. load-transfer assembly—the unit (basket or plate) designed low-pressure steam curing—see curing, atmospheric- to support or link dowel bars during concreting operations pressure steam (preferred term). so as to hold them in place while in the desired alignment. low-strength materials—see controlled low-strength ce- loading, bulk—loading of unbagged cement in containers, mentitious material (preferred term). specially designed trucks, railroad cars, or ships. L-shore—a shore with an L-head. (See also L-head.) loading, dynamic—loading from units (particularly ma- lubricant, dowel—a material applied to part of the surface chinery) that, by virtue of their movement or vibration, of a dowel to reduce bond with the concrete and permit impose stresses in excess of those imposed by their dead axial movement. load. loading, ribbon—method of batching concrete in which the M solid ingredients, and sometimes also the water, enter the mixer simultaneously. macadam, cement-bound—a road consisting of crushed loading hopper—a hopper in which concrete or other free- stone, crushed slag, or gravel and either a grout or mortar flowing material is deposited for discharge into buggies or filler; formed by rolling a base of stone, slag, or gravel to other conveyances used for delivery to the forms or to oth- a compacted mass having an even surface, and then roll- er place of processing, use, or storage. ing in the cementitious filler. locking device—a device used to secure a cross brace in machine, finishing—a power-operated machine used to scaffolding to the frame or panel. produce the desired surface texture on a concrete slab. long column—see column, long. machine-base grout—see grout, machine base.

116R-38 ACI COMMITTEE REPORT melilite macroscopic—visible to the naked eye (preferred term). ferred to by indicating the type of mineral aggregate incor- magnetite—a mineral, ferrous ferric oxide (FeO·Fe2O3); porated (for example, lightweight or sand-gravel block). the principal constituent of magnetic black iron ore; den- masonry wall, solid—a wall built of blocks or solid masonry sity approximately 5.2 g/cc and Mohs hardness approxi- units, the mortar completely filling the joints between mately 6; used as an aggregate in high-density concrete. units. manual batcher—see batcher manual. mason’s putty—a pasty substance, composed of water and manufactured sand—see sand. hydrated lime mixed with portland cement and stone dust; map cracking—see cracking, map. used only for jointing ashlar masonry. marble—a metamorphic rock composed essentially of re- mass—the physical property of matter that causes it to have crystallized calcite, dolomite, or both. weight in a gravitational field; the quantity of matter in a marl—calcareous clay, usually containing from 35 to 65% body. calcium carbonate (CaCO3), found in the bottoms of shal- mass concrete—see concrete, mass. low lakes, swamps, or extinct fresh-water basins. mass curing—see curing, mass. mason—an artisan who builds with concrete masonry units, mass density—see density. bricks, stone, and tile; name sometimes given a concrete mat—see bar mat. finisher. mat foundation—see foundation, mat. masonry—construction composed of shaped or molded material hose—see hose, delivery. units, usually small enough to be handled by one person materials, cementitious—cements and pozzolans used in and composed of stone, ceramic brick or tile, concrete, concrete and masonry construction. (See also blast-fur- glass, adobe, or the like. nace slag; cement, hydraulic; masonry; and mortar.) masonry, ashlar—masonry composed of bonded blocks matrix—in the case of mortar, the cement paste in which the of concrete, either rectangular or square, always of fine aggregate particles are embedded; in the case of con- two or more sizes; if the pattern is repeated, it is pat- crete, the mortar in which the coarse aggregate particles terned ashlar; if the pattern is not repeated, it is ran- are embedded. dom ashlar. mats, cotton—cotton-filled quilts fabricated for use as a wa- masonry, bonded hollow-wall—a cavity wall, built of ter-retaining covering in curing concrete surfaces. masonry units, in which the inner and outer walls are maturity factor—see factor, maturity. tied together by bonders. maximum service temperature (refractory concrete)— masonry, exposed—masonry constructed to have no the temperature above which excessive shrinkage occurs surface finish other than paint. in refractory concrete; usually between 150 F (66 C) and masonry, grouted—unit masonry composed of either 200 F (93 C) below the temperature at which the refracto- hollow units wherein the cells are filled with grout or ry concrete softens. multiple wythes where spaces between the wythes are maximum size (of aggregate)—in specifications for and in filled with grout. description of aggregate, the smallest sieve opening masonry, hollow-unit—masonry consisting either entire- through which the entire amount of aggregate is required ly or partially of hollow masonry units laid in mortar. to pass. (See also nominal maximum size [of aggre- masonry, plain— gate].) 1. masonry without reinforcement; or maximum-temperature period—a time interval through- 2. masonry reinforced only for shrinkage or thermal out which the maximum temperature is held constant in change. an autoclave or steam-curing room. masonry, reinforced—unit masonry in which reinforce- mean stress—see stress, mean. ment is embedded in such a manner that the two materi- mechanical analysis—the process of determining particle- als act together in resisting forces. size distribution of an aggregate. (See analysis, sieve.) masonry, solid-unit—masonry consisting wholly of sol- mechanical anchorage—see anchorage, mechanical. id masonry units laid in mortar. mechanical bond—see bond, mechanical. masonry, unit—a structural element consisting of con- mechanical connection—the complete assembly of an end- crete masonry units usually bonded by mortar, grout, bearing sleeve, a coupler, or a coupling sleeve, and possi- or both. bly additional intervening material or other components masonry cement—see cement, masonry. to effect connection of reinforcing bars. (See also bar- masonry filler unit—masonry unit used to fill in between end check; coupler; coupling sleeve; and end-bearing joists or beams to provide a platform for a cast-in-place sleeve.) concrete slab. medium, grinding—a hard, free-moving charge in a ball or masonry grout—see grout, masonry. tube mill to reduce the particle size of introduced materi- masonry lift—the height to which masonry is laid between als by attrition or impact. periods of grouting. megascopic—see macroscopic (preferred term). masonry unit, concrete—either a hollow or solid unit melilite—a group of minerals ranging from the calcium (block) composed of portland-cement concrete; often re- magnesium silicate (akermanite) to the calcium aluminate

CEMENT AND CONCRETE TERMINOLOGY 116R-39 melt

silicate (gehlenite) that occur as crystals in blast-furnace microsilica—see silica fume (preferred term). slag. (See also akermanite; gehlenite; and merwinite.) middle strip—see strip, middle. melt—the molten portion of the raw material mass during mill, ball—horizontal, cylindrical, rotating mill charged the burning of cement clinker, firing of lightweight aggre- with large grinding media. (See also mill, rod.) gates, or expanding of blast-furnace slags. mill, rod—horizontal, cylindrical, rotating mill charged with member, compression—any member in which the primary steel rods for grinding. (See also mill, ball.) stress is longitudinal compression. mill scale—the partially adherent layers of oxidation prod- member, segmental—a structural member made up of indi- ucts (heavy oxides) developed on metallic surfaces during vidual elements prestressed together to act as a monolithic either hot fabrication or heat treatment of metals, as on unit under service loads. hot-rolled steel reinforcing bars. membrane curing—see curing, membrane. mineral aggregate—see aggregate, mineral. membrane theory—a theory of design for thin shells, based 
  
 (       %#    on the premise that a shell cannot resist bending because 74() #    6"" µ  it deflects; the only stresses that exist in any section, there- "   fore, are shear stress and direct compression or tension. mix (n.)—see mixture. merwinite—one of the principal crystalline phases found in mix (v.)—the act or process of mixing; also, a mixture of ma- blast-furnace slags; the chemical formula is terials, such as mortar or concrete. Ca3Mg(SiO4)2, the crystal system is monoclinic, and the mix, dry—a concrete, mortar, or plaster mixture, commonly density is 3.15 g/cc. (See also akermanite; gehlenite; and sold in bags, containing all components except water; also melilite.) a concrete of near zero slump. mesh—the number of openings (including fractions thereof) mix design—see mixture proportioning (preferred term). per unit of length in either a screen or sieve in which the mixer—a machine used for blending the constituents of con- openings are 1/4 in. (6 mm) or less. crete, grout, mortar, cement paste, or other mixture. mesh, diamond—a metallic fabric having rhomboidal open- mixer, batch—a machine that mixes batches of either ings in a geometric pattern. (See also lath, expanded- concrete or mortar. metal.) mixer, central—a stationary concrete mixer from which mesh reinforcement—see fabric, welded-wire and reinforce- the freshly mixed concrete is transported to the work. ment, welded-wire fabric. mixer, colloidal—a mixer designed to produce colloidal mesh roller—a finishing tool consisting of a rolling drum at- grout. tached to a handle, of which the surface of the drum is mixer, continuous—a mixer into which the ingredients made of mesh, sometimes used for rolling over the surface of the mixture are fed without stopping, and from of fresh concrete to embed coarse aggregate. which the mixed product is discharged in a continuous Mesnager hinge—see hinge, Mesnager. stream. meter, air—a device for measuring the air content of con- mixer, high-discharge—see mixer, inclined-axis (pre- crete and mortar. ferred term). method, advancing-slope—a method of placing concrete as mixer, horizontal-axis—a concrete mixer of the revolv- in tunnel linings in which the face of the fresh concrete is ing drum type in which the drum rotates about a hori- not vertical and moves forward as concrete is placed. zontal axis. microconcrete—a mixture of portland cement, water, and mixer, horizontal-shaft—a mixer having a stationary suitably graded sand for simulating concrete in small- cylindrical mixing compartment, with the axis of the scale structural models. cylinder horizontal, and one or more rotating horizon- microcracks—microscopic cracks within concrete. tal shafts to which mixing blades or paddle are at- 
 $    % (  5% tached; also called pugmill.   %   (       mixer, inclined-axis—a truck with a revolving drum that (! % $ #µ rotates about an axis inclined to the bed of the truck 

(   6"" * chassis. µ*      ((#   mixer, nontilting—a horizontal rotating drum mixer that microscope, polarizing—a microscope equipped with ele- charges, mixes, and discharges without tilting. ments permitting observations and determinations to be mixer, open-top—a truck-mounted mixer consisting of a made using polarized light. (See also Nicol prism.) trough or a segment of a cylindrical mixing compart- microscope, scanning electron (SEM)—an electron micro- ment within which paddles or blades rotate about the scope in which the image is formed by a beam operating horizontal axis of the trough. (See also mixer, hori- in synchronism with an electron probe scanning the ob- zontal-shaft and mixer, open-top.) ject; the intensity of the image-forming beam is propor- mixer, paddle—see open-top mixer (preferred term). tional to the scattering or secondary emission of electrons mixer, pan—see mixer, vertical shaft. by the specimen where the probe beam strikes it. mixer, revolving-blade (or paddle)—see mixer, open- microscopic—discernible only with the aid of a microscope. top.

116R-40 ACI COMMITTEE REPORT modulus

mixer, tilting—a revolving-drum mixer that discharges by site for conveying concrete from the ready-mixed con- tilting the drum about a fixed or movable horizontal crete truck to the forms or slab. axis at right angles to the drum axis; the drum axis may moderate sulfate-resisting cement—see cement, moder- be horizontal or inclined while charging and mixing. ate sulfate-resisting. mixer, transit—see mixer, truck. modified cube—a portion of a rectangular beam of hard- mixer, trough—see mixer, open-top (preferred term). ened concrete previously broken in flexure; used in deter- mixer, truck—a concrete mixer suitable for mounting on mining the compressive strength of the concrete. a truck chassis and capable of mixing concrete in tran- modified portland cement—a portland cement having sit. (See also mixer, horizontal-axis; mixer, in- moderate heat of hydration; this term was replaced by clined-axis; mixer, open-top; and agitator.) Type II cement beginning in 1960. (See also cement, mixer, tub—see mixer, open-top (preferred term). modified.) mixer, turbine—see mixer, open-top (preferred term). modular ratio—the ratio of modulus of elasticity of steel Es mixer, vertical-shaft—a cylindrical or annular mixing to that of concrete Ec; usually denoted by the symbol n. compartment having an essentially level floor and module—any in a series of standardized units for use togeth- containing one or more vertical rotating shafts to er in erecting a structure. which blades or paddles are attached; the mixing com- modulus— partment may be stationary or rotate about a vertical modulus, bulk—the ratio of the change in average stress axis. to the change in unit volume. (See also modulus of mixer efficiency—the adequacy of a mixer in rendering a compression.) homogeneous product within a stated period; homogene- modulus, chord—see modulus of elasticity. ity is determinable by testing for relative differences in modulus, elastic—see modulus of elasticity (preferred physical properties or composition of samples extracted term). from different portions of a freshly mixed batch.     
(#$ $   mixing cycle—the time taken for a complete cycle in a batch #  (     #  mixer, that is, the time elapsing between successive rep-   # ( ()   #%% # & etitions of the same operation (for example, successive         %$* 8* µ discharges of the mixer). * ! µ !7 µ !** mixing, dry—blending of the solid materials for mortar or *7! 7!!  concrete before adding the mixing water.  !*   !*&*  ! mixing plant—see batch plant (preferred term).  ! * 7  mixing speed—rotation rate of a mixer drum or of the pad- modulus, initial-tangent—see modulus of elasticity. dles in an open-top, pan, or trough mixer, when mixing a modulus, secant—see modulus of elasticity. batch; expressed in revolutions per minute (rpm), or in modulus, section—a term pertaining to the cross section peripheral feet per minute of a point on the circumference of a flexural member; the section modulus with respect at maximum diameter. to either principal axis is the moment of inertia with re- mixing time—the period during which the constituents of a spect to that axis divided by the distance from that axis batch of concrete are mixed by a mixer; for a stationary to the most remote point of the tension or compression mixer, time is given in minutes from the completion of area of the section, as required; the section modulus is mixer charging until the beginning of discharge; for a used to determine the flexural stress in a beam. truck mixer, time is given in total minutes at a specified modulus, shear—see modulus of rigidity. mixing speed or expressed in terms of total revolutions at modulus, sonic—see modulus of elasticity, dynamic. a specified mixing speed. (See also amount of mixing.) modulus, subgrade—see coefficient of subgrade reac- mixing water—see water, mixing. tion. mixture—the assembled, blended, commingled ingredients modulus, tangent—see modulus of elasticity. of mortar, concrete, or the like; or the proportions for modulus, Young’s—see modulus of elasticity (pre- their assembly. ferred term). mixture, harsh—a concrete mixture that lacks desired     
  (#   workability and consistency due to a deficiency of #%$ ##  !)   (  # %$& mortar or aggregate fines.  # ! . )  $%.%% !9% : mixture, lean—see concrete, lean. %%  ;  :  $ 5%  
<÷ mixture, rich—see rich mixture. *= µ) <$%.%% !<9% : %% ! mixture proportion—the proportions of ingredients that  µ<;  :  (  % # & make the most economical use of available materials to    produce mortar or concrete of the required properties. modulus of deformation— (See also proportion.) 1. a concept of modulus of elasticity expressed as a func- mobile placer—a small belt conveyor, mounted on wheels tion of two time variables; strain in loaded concrete as or truck-mounted, that can be readily moved to the job a function of the age at which the load is initially ap-

CEMENT AND CONCRETE TERMINOLOGY 116R-41 modulus

plied and of the length of time the load is sustained; and modulus of subgrade reaction—see coefficient of sub- 2. the ratio of stress to strain for a material that does not grade reaction. deform in accordance with Hooke’s law when subject- Mohs scale—arbitrary quantitative units, ranging from 1 ed to applied load. (See also modulus of elasticity.) through 10, by means of which the scratch hardness of a modulus of elasticity—the ratio of normal stress to corre- mineral is determined; each unit of hardness is represent- sponding strain for tensile or compressive stress below the ed by a mineral that can scratch any other mineral having proportional limit of the material; also referred to as elas- a lower-ranking number; the minerals are ranked from: tic modulus, Young’s modulus, and Young’s modulus of talc, or 1 (the softest); gypsum, or 2; calcite, or 3; fluorite, elasticity; denoted by the symbol E. (See also modulus of or 4; apatite, or 5; orthoclase, or 6; quartz, or 7; topaz, or rigidity.) 8; corundum, or 9; and diamond, or 10 (the hardest). Note: few materials conform to Hooke’s law throughout the moist—slightly damp but not quite dry to the touch; the entire range of stress-strain relations; deviations there- terms “wet” implies visible free water, “damp” implies from are caused by inelastic behavior. If the deviations are less wetness than “wet,” and “moist” implies not quite significant, the slope of the tangent to the stress-strain dry. (See also damp and wet.) curve at the origin, the slope of the tangent to the stress- moist-air curing—see curing, moist-air. strain curve at any given stress, the slope of the secant moist cabinet—see cabinet, moist. drawn from the origin to any specified point on the stress- moist room—a room in which the atmosphere is maintained at strain curve, or the slope of the chord connecting any two a selected temperature (usually 23.0 ± 2 C or 73.0 ± 3.0 F) specified points on the stress-strain curve, may be consid- and a relative humidity of at least 95%, for the purpose of ered as the modulus; in such cases, the modulus is desig- curing and storing cementitious test specimens; the facilities nated, respectively, as the initial tangent modulus, the must be sufficient to maintain free moisture continuously on tangent modulus, the secant modulus, or the chord modu- the exteriors of test specimens; also known as a fog room. lus, and the stress stated. The modulus is expressed as moisture— force per unit of area (for example, psi or Pa). moisture, absorbed—moisture that has entered the per- modulus of elasticity, dynamic—the modulus of elas- meable voids of a solid and has physical properties not ticity computed from the size, weight, shape, and fun- substantially different from ordinary water at the same damental frequency of vibration of a concrete test temperature and pressure. (See also absorption.) specimen, or from pulse velocity. (See also modulus moisture, free—moisture having essentially the proper- of elasticity, static and velocity, pulse.) ties of pure water in bulk; moisture not absorbed by ag- gregate. (See also moisture, surface.) modulus of elasticity, static—the value of Young’s moisture, surface—free water retained on surfaces of ag- modulus of elasticity obtained by arbitrary criteria gregate particles and considered to be part of the mixing from measured stress-strain relationships derived water in concrete, as distinguished from absorbed mois- from other than dynamic loading. (See also modulus ture. of elasticity.) moisture barrier—see barrier, moisture. modulus of elasticity, sustained—term including elastic moisture content of aggregate—the ratio, expressed as a and inelastic effects in one expression to aid in visual- percentage, of the mass of water in a given granular mass izing net effects of stress-strain up to any given time; to the dry weight of the mass. computed by dividing the unit sustained stress by the moisture content of concrete masonry unit—the amount sum of the elastic and inelastic deformations at that of water contained in the hardened concrete at the time of time. (See also modulus of elasticity.) sampling and expressed as a percentage of its capacity for modulus of resilience—see resilience. total absorption. modulus of rigidity—the ratio of unit shearing stress to the moisture-free—the condition of a material that has been corresponding unit shearing strain; referred to as shear dried in air until there is no further significant change in modulus and modulus of elasticity in shear, denoted by its mass. (See also mass and ovendry.) the symbol G. (See also modulus of elasticity.) moisture movement— modulus of rupture—a measure of the load-carrying capac- 1. the movement of moisture through a porous medium; and ity of a beam and sometimes referred to as rupture modu- 2. in the UK, the effects of such movement on efflorescence lus or rupture strength; it is calculated for apparent tensile and volume change in hardened cement paste, mortar, stress in the extreme fiber of a transverse test specimen concrete, or rock. (See also shrinkage and swelling.) under the load that produces rupture. (See also strength, mold— flexural.) 1. a device containing a cavity into which neat cement, Note: the actual stress in the extreme fiber is less than the ap- mortar, or concrete test specimens are cast; and parent stress since the flexure formula employed in the 2. a form used in the fabrication of precast mortar or con- calculation is valid only for stresses within the proportion- crete units (for example, masonry units). al limit of the material; nevertheless, the nominal rupture mold, plaster— a mold or form made from gypsum plas- strength so obtained is considered the rupture modulus. ter, usually to permit concrete to be formed or cast in

116R-42 ACI COMMITTEE REPORT mushroom

intricate shapes or in conspicuous relief. (See also mortar—a mixture of cement paste and fine aggregate; in mold and form.) fresh concrete, the material occupying the interstices mold oil—see oil, mold. among particles of coarse aggregate; in masonry con- moment—the colloquial expression for the more descriptive struction, joint mortar may contain masonry cement, or term, bending moment. (See also moment, bending.) may contain hydraulic cement with lime (and possibly moment, bending—the bending effect at any section of other admixtures) to afford greater plasticity and work- a structural element; it is equal to the algebraic sum of ability than are attainable with standard portland cement the moments of the vertical and horizontal forces, with mortar. (See also cement, hydraulic and masonry.) respect to the centroidal axis of a member, acting on a mortar, air-blown—see shotcrete (preferred term). freebody of the member. mortar, expansive-cement—see concrete (mortar or moment, negative—a condition of flexure in which top grout), expansive-cement. fibers of a horizontally placed member, or external fi- mortar, epoxy—a mixture of epoxy resin, catalyst, and bers of a vertically placed exterior member, are sub- fine aggregate. (See also resins, epoxy.) jected to tensile stresses. mortar, fat—mortar containing a high percentage of moment, positive—a condition of flexure in which, for a fine-grained solid components; sufficiently sticky to horizontal simply supported member, the deflected adhere to a steel trowel. shape is normally considered to be concave downward mortar, lean—mortar that is harsh and difficult to spread and the top fibers subjected to compression stresses; because of either insufficient cement content or the for other members and other conditions consider pos- presence of coarse sand. itive and negative as relative terms. (See also mo- mortar, plastic—a mortar of plastic consistency. ment, negative.) mortar, resin—see concrete, polymer. Note: for structural design and analysis, moments may be mortar, sprayed—see shotcrete (preferred term). designated as positive or negative with satisfactory re- mortar, stringing—the procedure of spreading enough sults as long as the sign convention adopted is used mortar on the bed joint to ensure laying several mason- consistently. ry units. moment, secondary—in statically indeterminate struc- mortar board—a platform or tray for holding freshly mixed tures, the additional moments caused by deformation mortar. (See also hawk and hod.) of the structure due to the applied forces; in statically mortar-flow—see flow 2. indeterminate prestressed-concrete structures, the ad- mosaic—inlaid exposed surface designs of aggregates or ditional moments caused by the use of a nonconcor- other material. dant prestressing tendon. moving forms—see forms, moving. moment, ultimate—obsolete term; see strength, flexural. mud balls—lumps of clay or silt (“mud”). moment distribution—a method of structural analysis for mudjacking—see slabjacking (preferred term). continuous beams and rigid frames whereby successive mud pumping—see pumping (of pavements). converging corrections are made to an assumed set of mud sill—a timber or timber assembly bedded into the earth moments until the desired precision is obtained; also at grade to support framed construction. known as the Hardy Cross method. mud slab—a 2 to 6 in. (50 to 150 mm) layer of concrete be- monolith—a body of plain or reinforced concrete cast or neath a structural concrete floor or footing over soft, wet erected as a single integral mass or structure. soil; also called mud mat. monolithic concrete—see concrete, monolithic. multielement prestressing—prestressing accomplished by monolithic surface treatment—see dry-shake. stressing an assembly of several individual structural ele- monolithic terrazzo—the application of a 5/8 in. (15 mm) ments as a means of producing one integrated structural terrazzo topping directly to a specially prepared concrete member. substrate, eliminating an underbed. multistage stressing—prestressing performed in stages as monolithic topping—see topping, monolithic. the construction progresses. monomer—an organic molecule of relatively low molecu- multiwall-bag—a flexible container for transporting a ce- lar weight that creates a solid polymer by reacting with it- mentitious material and usually consisting of four plies of self or other compounds of low molecular weight or both. kraft paper previously treated to ensure resistance to monomolecular—composed of single molecules; specifi- moisture. cally, films that are one molecule thick; denotes a thick- muriatic acid—see hydrochloric acid (preferred term). ness equal to one molecule, for example, certain chemical mushroom system of flat-slab construction—a four-way compounds develop a monomolecular film over bleeding reinforced-concrete girderless floor slab in which the col- water at the surface of freshly placed concrete or mortar umn reinforcing bars are bent down into the slab around the as a means of reducing the rate of evaporation. (See also column head in radial directions and additional reinforcing evaporation retardant.) bars are bent into rings laid upon the radials, thus forming montmorillonite—a swelling clay mineral of the smectite a spider web to provide additional reinforcement at the group; main constituent of bentonite. (See also smectite.) column head and to support the slab steel; mushroom de-

CEMENT AND CONCRETE TERMINOLOGY 116R-43 nailable

signs of the true flat-slab type do not involve drop panels nonair-entrained concrete—see concrete, nonair-en- around the capitals of the columns. trained. nonbearing wall—see wall, nonbearing. N noncombustible—any material that neither ignites nor sup- ports combustion in air when exposed to fire. nailable concrete—see concrete, nailable. nonconcordant tendons—see tendons, nonconcordant. nailer—a strip of wood or other fitting attached to or set in nonevaporable water—see water, nonevaporable. concrete, or attached to steel, to facilitate making nailed nonferrous—relating to metals other than iron; not contain- connections. ing or including iron. natural air-drying—the process of drying cured concrete nonprestressed reinforcement—see reinforcement, non- masonry units without any special equipment (for exam- prestressed. ple, the drying that occurs in a covered storage area). nonrecoverable creep—see creep, nonrecoverable. natural cement—see cement, natural. nonreversible deformation—see creep, nonrecoverable natural pozzolan—see pozzolan, natural. (preferred term). natural sand—see sand, natural. nonsimultaneous prestressing—see prestressing, nonsi- neat cement grout—see grout, neat-cement. multaneous. neat cement paste—see cement paste, neat. nonslip concrete—see concrete, nonslip. neat line—a line defining the proposed or specified limits of nonstaining cement—see cement, nonstaining. an excavation or structure. nonstructural reinforcement—see reinforcement, tem- neat plaster—see plaster, neat. perature. necking—the localized and permanent reduction of cross- nontilting mixer—see mixer, nontilting. sectional area of a test specimen of metal; due to stretch- normal cement—see cement, normal. ing produced by applied tensile load. normal consistency—see consistency, normal. needle, Gillmore—a device used in determining time of set- normal portland cement—see cement, normal. ting of hydraulic cement. normal stress—see stress, normal. needle, Vicat—a weighted needle for determining time of normalweight aggregate—see aggregate, normalweight. setting of hydraulic cements. normalweight concrete—see concrete, normalweight. negative catalyst—see catalyst, negative. normalweight refractory concrete—see concrete, nor- negative moment—see moment, negative. malweight refractory. negative reinforcement—see reinforcement, negative. no-slump concrete—see concrete, no-slump. negative-slump concrete—see concrete, negative-slump. nozzle—a metal or rubber tip attached to the discharge end net cross-sectional area (of masonry)—the gross cross- of a heavy thick-walled rubber hose from which a contin- sectional area of a section of masonry minus the area of uous stream of shotcrete is ejected at high velocity. cavities, cells, or cored spaces. nozzle liner—a replaceable rubber lining, fitted into the noz- zle tip, to prevent abrasion of the interior surface of the net mixing water—see water, mixing. nozzle. neutral axis—see axis, neutral. nozzle operator—the operator who manipulates the nozzle neutral refractory—see refractory, neutral. and controls placement of the shotcrete; in the case of dry- Nicol prism—a system of two optically clear crystals of cal- mix shotcrete, the operator also controls the water content cite (“Iceland spar”) used in producing plane-polarized of the shotcrete. light. nozzle velocity—the rate at which shotcrete is ejected from nip—the seizing of stone between either the jaws or the rolls the nozzle, usually stated in ft per s or m per s. of a crusher. no-fines concrete—see concrete, no-fines. O nominal flexural strength—see strength, nominal flexural. nominal maximum size (of aggregate)—in specifications for obsidian—a natural volcanic glass of relatively low water and in descriptions of aggregate, the smallest sieve opening content; usually of rhyolite composition. (See also perlite.) through which the entire amount of the aggregate is permit- offset—an abrupt change in alignment or dimension, either ted to pass. (See also maximum size [of aggregate].) horizontally or vertically; a horizontal ledge occurring nominal mixture—the proportions of the constituents of a along a change in wall thickness of the wall above. proposed concrete mixture. offset bend—an intentional distortion from the normal nominal shear strength—see strength, nominal shear. straightness of a steel reinforcing bar to move the center nominal size—see nominal maximum size (of aggregate). line of a segment of the bar to a position parallel to the nominal strength—see strength, nominal. original position of the center line; a mechanical opera- nonagitating unit—a truck-mounted container for trans- tion commonly applied to vertical bars that reinforce con- porting central-mixed concrete, not equipped to provide crete columns. agitation (slow mixing) during delivery. offset yield strength—see strength, offset yield.

116R-44 ACI COMMITTEE REPORT panel oil, form—oil applied to the interior surfaces of forms to pro- owner—the corporation, association, partnerships, individual, mote easy release from the concrete when the forms are re- or public body or authority with whom the contractor enters moved. (See also agent, release and bond breaker.) into an agreement and for whom the work is provided. oil, mold—an oil that is applied to the interior surface of a oxide, brown—a brown mineral pigment having an iron ox- clean mold, before casting concrete or mortar therein, to ide content between 28 and 95%. (See also limonite.) facilitate removal of the mold after the concrete or mortar has hardened. (See also bond breaker; oil, form; and P agent, release.) oil-well cement—see cement, oil-well. pack, dry—concrete or mortar mixtures deposited and con- one-way system—see system, one-way. solidated by dry packing. 

   #  (  %  %   # pack, warehouse—see set, warehouse. pack set—see cement, sticky and set, warehouse. " , ⋅ - , opaline chert—chert composed entirely or mainly of opal. packaged concrete, mortar, grout—mixtures of dry ingre- dients in packages, requiring only the addition of water to open-circuit crushing—a crushing system in which materi- produce concrete, mortar, or grout. al passes through the crusher without recycling of over- packer—a device inserted into a hole in which grout is to be size particles. injected which acts to prevent return of the grout around open-circuit grouting—see grouting, open-circuit. the injection pipe; usually an expandable device actuated open-graded aggregate—see aggregate, open-graded. mechanically, hydraulically, or pneumatically. open-top mixer—see mixer, open-top. packerhead process—see process, packerhead. ordinary portland cement—see cement, ordinary port- packing, dry—placing of zero-slump or near zero-slump land. concrete, mortar, or grout by ramming into a confined orthotropic—a contraction of the terms “orthogonal aniso- space. tropic” as in the phrase “orthogonal anisotropic plate”; a paddle mixer—see mixer, open-top (preferred term). hypothetical plate consisting of beams and a slab acting paint, cement—a paint consisting generally of white port- together with different flexural rigidities in the longitudi- land cement and water, pigments, hydrated lime, water re- nal and transverse directions, as in a composite beam pellents, or hygroscopic salts. bridge. paint, cold-water—a paint in which the binder or vehicle ovals—marble chips that have been tumbled until a smooth portion is composed of latex, casein, glue, or some similar oval shape has resulted. material dissolved or dispersed in water. oven-dry—the condition resulting from having been dried Palladiana—see Berliner. to essentially constant mass, in an oven, at a temperature pan— that has been fixed, usually between 221 and 239 F (105 1. a prefabricated form unit used in concrete joist floor and 115 C). construction; and oven dry—the process of drying in an oven at a temperature 2. a container that receives particles passing the finest usually between 221 and 239 F (105 and 115 C) until the sieve during mechanical analysis of granular materials. mass of the test specimen becomes essentially constant. pan mixer—see mixer, vertical shaft (preferred term). overdesign—to require adherence to structural design re- panel— quirements higher than service demands, as a means of 1. a section of form sheathing, constructed from boards, compensating for statistical variation or for anticipated plywood, metal sheets, etc., that can be erected and deficiencies or both. stripped as a unit; and overlay—a layer of concrete or mortar, seldom thinner than 1 2. a concrete member, usually precast, rectangular in in. (25 mm), placed on and usually bonded onto the worn shape, and relatively thin with respect to other dimen- or cracked surface of a concrete slab to either restore or im- sions. prove the function of the previous surface; also polymeric panel, drop—the thickened structural portion of a flat concrete usually less than 0.4 in. (10 mm) thick. slab in the area surrounding column, column capital, or oversanded—containing more sand than would be neces- bracket, to reduce the intensity of stresses. sary to produce adequate workability and a satisfactory panel, exterior—in a flat slab, a panel having at least one condition for finishing. edge that is not in common with another panel. overstretching—stressing of tendons to a value higher than panel, ribbed—a panel composed of a thin slab reinforced designed for the initial stress to: (a) overcome frictional by a system of ribs in one or two directions, usually or- losses; (b) temporarily overstress the steel to reduce steel thogonal. creep that occurs after anchorage, and (c) counteract loss panel, sandwich—a prefabricated panel that is a layered of prestressing force that is caused by subsequent pre- composite, formed by attaching two thin facings to a stressing of other tendons. thicker core, for example, a precast-concrete panel overvibration—excessive use of vibrators during place- consisting of two layers of concrete separated by a ment of freshly mixed concrete, causing segregation, nonstructural insulating core. stratification, and excessive bleeding. panel, solid—a solid slab, usually of constant thickness.

CEMENT AND CONCRETE TERMINOLOGY 116R-45 panel panel strip—see strip, panel. paving train—an assemblage of equipment designed to paper form—see form, paper. place and finish a concrete pavement. parallel-wire unit—a post-tensioning tendon composed of a pea gravel—see gravel, pea. number of wires or strands that are approximately parallel. pedestal—an upright compression member whose height parapet—the part of a wall that extends above the roof level; does not exceed three times its average least dimension, a low wall along the top of a dam. such as a short pier or plinth used as the base for a column. parge—to coat with plaster, particularly foundation walls pedestal pile—see pile, pedestal. and rough masonry. (See also back plastering.) peeling—a process in which thin flakes of mortar are broken partial prestressing—see prestressing, partial. away from a concrete surface, such as by deterioration or by partial release—see release, partial. adherence of surface mortar to forms as forms are removed. 
 

 # ##  # & pencil rod—see rod, pencil.     *µ    # #  %% penetration—an opening through which pipe, conduit, or  % other item passes through a wall or floor. particle shape—the form of a particle. (See also cubical penetration probe—see probe, penetration. piece [of aggregate]; elongated piece [of aggregate]; penetration resistance—see resistance, penetration.    
  %  '     #  ( and flat piece [of aggregate].)   (      % %  particle-size distribution—see grading. µ !  % ((   parting agent—see agent, release. # # '%'  # $$ %& pass—layer of shotcrete placed in one movement over the %( % ( area of operation. percentage of reinforcement—the ratio of cross-sectional paste—see cement paste, neat. area of reinforcing steel to the effective cross-sectional paste, cement—binder of concrete and mortar consisting es- area of a member, expressed as a percentage. sentially of cement, water, hydration products and any ad- periclase—a crystalline mineral, magnesia, MgO, the equiv- mixtures together with very finely divided materials alent of which may be present in portland-cement clinker, included in the aggregates. (See also cement paste, neat.) portland cement, and other materials, such as open-hearth paste content—proportional volume of cement paste in con- slags and certain basic refractories. crete, mortar, or the like, expressed as volume percent of perimeter grouting—see grouting, perimeter. the entire mixture. (See also cement paste, neat.) period— paste volume—see paste content. period, precuring—see period, presteaming (preferred pat—a specimen of neat cement paste, approximately 3 in. term). (76 mm) in diameter and 1/2 in. (13 mm) in thickness at period, presteaming—in the manufacture of concrete the center and tapering to a thin edge, on a flat glass plate products, the time between molding of a concrete for indicating setting time. product and start of the temperature-rise period. path of prestressing force—the locus of points defining the period, soaking—in high-pressure and low-pressure resultant effective prestress force in a concrete member. steam curing, the time during which the live steam pattern cracking—see cracks, craze and cracking, map. supply to the kiln or autoclave is shut off and the con- pattern cracks—see cracks, craze and cracking, map. crete products are exposed to the residual heat and patterned ashlar—see masonry, ashlar. moisture. pavement (concrete)—a layer of concrete on such areas as period, temperature-rise—the time interval during roads, sidewalks, canals, playgrounds, and those used for which the temperature of a concrete product rises at a storage or parking. (See also pavement, rigid.) controlled rate to the desired maximum in autoclave or pavement, flexible—a pavement structure that maintains atmospheric-pressure steam curing. intimate contact with and distributes loads to the sub- period at maximum temperature—see maximum-tem- grade and depends on aggregate interlock, particle fric- perature period. tion, and cohesion for stability; cementing agents, perlite—a volcanic glass having a perlitic structure, usually where used, are generally bituminous materials as con- having a higher water content than obsidian; when ex- trasted to hydraulic cement in the case of rigid pave- panded by heating, used as an insulating material and as a ment. (See also pavement, rigid.) lightweight aggregate in concretes, mortars, and plasters. pavement, rigid—pavement that will provide high bend- perlitic structure—a structure produced in a homogeneous ing resistance and distribute loads to the foundation material by contraction during cooling and consisting of a over a comparatively large area. system of irregular convolute and spheroidal cracks; gen- paver, concrete— erally confined to natural glass. 1. a concrete mixer, usually mounted on crawler tracks, permanent form—see form, permanent. that mixes and places concrete pavement on the sub- permanent set—see set, permanent. grade. permeability to water, coefficient of—the rate of discharge 2. precast-concrete paving brick. of water under laminar flow conditions through a unit

116R-46 ACI COMMITTEE REPORT plastic

cross-sectional area of a porous medium under a unit hy- pile, pedestal—a cast-in-place concrete pile constructed so draulic gradient and standard temperature conditions, that concrete is forced out into a widened bulb or pedes- usually 20 C. tal shape at the foot of the pipe that forms the pile. pessimum—worst; the opposite of optimum. pile, pipe— a steel cylinder, usually between 10 and 24 petrography—the branch of petrology dealing with descrip- in. (250 and 600 mm) in diameter, generally driven tion and systematic classification of rocks aside from their with open ends to firm bearing and then excavated and geologic relations, mainly by laboratory methods, largely filled with concrete. chemical and microscopical; also, loosely, petrology or li- pile, precast—a reinforced pile manufactured in a cast- thology; also the techniques and knowledge of petrography ing plant or at the site but not in its final position. (See applied to mortar, concrete, and the like. also pile, cast-in-place.) petrology—the science of rocks, treating their origin, struc- pile, raking—see pile, batter (preferred term). ture, composition, etc., from aspects and in all relations. pile, sheet—a pile in the form of a plank driven in close (See also petrography.) contact or interlocking with others to provide a tight phenolic resin—see resin, phenolic. wall to resist the lateral pressure of water, adjacent earth, or other materials; may be tongued and grooved phi (φ) factor—see factor, strength-reduction (preferred if made of timber or concrete and interlocking if made term). of metal. Philleo factor—see factor, Philleo. pipe, vent —a small-diameter pipe used in concrete con- photometer, flame—an instrument used to determine ele- struction to permit escape of air in a structure being ments (especially sodium and potassium in portland ce- concreted or grouted. ment) by the color intensity of their unique flame spectra pile, wing—a bearing pile, usually of concrete, widened resulting from introducing a solution of a compound of in the upper portion to form part of a sheet pile wall. the element into a flame. (Also known as flame spectro- pile bent—see bent, pile. photometer.) pile cap—see cap, pile. pier—isolated foundation member of either plain or reinforced pipe column—see column, pipe. concrete. pipe pile—see pile, pipe. pier, drilled—a concrete pier with or without a casing, cast- pitting—development of relatively small cavities in a sur- in-place in a hole previously bored in soil or rock. (See face; in concrete, localized disintegration, such as a pop- also pile, cast-in-place.) out; in steel, localized corrosion evident as minute pigment—a coloring matter, usually in the form of an insol- cavities on the surface. uble fine powder. placeability—see workability. pilaster—column built with a wall, usually projecting be- placement—the process of placing and consolidating concrete; yond the wall. a quantity of concrete placed and finished during a continu- pilaster face—see face, pilaster. ous operation; inappropriately referred to as pouring. pilaster side—see side, pilaster. placing—the deposition, distribution, and consolidation of pile—a timber, concrete, or steel structural element, driven, freshly mixed concrete in the place where it is to harden; jetted, or otherwise embedded on end in the ground for inappropriately referred to as pouring. the purpose of supporting a load or compacting the soil. plain bar—see bar, plain. (See also pile, composite.) plain concrete—see concrete, plain. pile, batter—a pile installed at an angle to the vertical; a plain masonry —see masonry, plain. raking pile or raker pile. plane of weakness—the plane along which a body under stress will tend to fracture; may exist by design, by accident, or be- pile, bored—see pier, drilled. cause of the nature of the structure and its loading. pile, caisson—a cast-in-place pile made by driving a plaster—a cementitious material or combination of cemen- tube, excavating it, and filling the cavity with con- titious material and fine aggregate that, when mixed with crete. a suitable amount of water, forms a plastic mass or paste pile, cast-in-place—a concrete pile concreted either with that when applied to a surface, adheres to it and subse- or without a casing in its permanent location, as distin- quently hardens, preserving in a rigid state the form or guished from a precast pile. (See also pier, drilled and texture imposed during the period of plasticity; also the pile, precast.) placed and hardened mixture. (See also stucco.) pile, composite—a pile made up of different materials, plaster, neat—plaster devoid of sand. usually concrete and wood, or steel fastened together plaster mold—see mold, plaster. end to end, to form a single pile. 


+",⋅* - ,! %() #  pile, concrete—see pile, cast-in-place and pile, precast. ( #  #$% )  $   (($ & pile, drilled—see pier, drilled. ! )   )  #$   )   )    pile, friction—a load-bearing pile that receives its prin- 5% #."   
 cipal vertical support from skin friction between the plastic—possessing plasticity, or possessing adequate plas- surface of the buried pile and the surrounding soil. ticity. (See also plasticity.)

CEMENT AND CONCRETE TERMINOLOGY 116R-47 plastic plastic cement—see cement, plastic. tersecting a sample of the solid. (See also linear-traverse plastic centroid—centroid of the resistance to load comput- method.) ed for the assumptions that the concrete is stressed uni- point count method (modified)—the point count method formly to 85% of its design strength, and the steel is supplemented by a determination of the frequency with stressed uniformly to its specified yield point. which areas of each component of a solid are intersected plastic consistency—see consistency, plastic. by regularly spaced lines in one or more planes intersect- plastic cracking—see cracking, plastic. ing a sample of the solid. plastic deformation—see deformation, inelastic. point load—see load, point. plastic flow—obsolete term for creep and stress relation. point of contraflexure—see point of inflection (preferred (See also creep; flow, plastic; and stress relaxation.) term). plastic hinge—see hinge, plastic. point of inflection—the point on the length of a structural plastic limit—see limit, plastic. member subjected to flexure where the curvature changes plastic loss—see creep. from concave to convex or conversely and at which the plastic mortar—see mortar, plastic. bending moment is zero; also called “point of contraflexure.” plastic or bond fire clay—a fire clay of sufficient natural Poisson’s ratio—see ratio, Poisson’s. plasticity to bond nonplastic material; a fire clay used as a polarizing microscope—see microscope, polarizing. plasticizing agent in mortar. pole shore—see shore, post. plastic shrinkage—see shrinkage, plastic. polish or final grind—the final operation in which fine plastic shrinkage cracks—see cracking, plastic. abrasives are used to hone a surface to its desired smooth- plasticity—a complex property of a material involving a ness and appearance. combination of qualities of mobility and magnitude of polyester—one of a large group of synthetic resins, mainly yield value; the property of freshly mixed cement paste, produced by reaction of dibasic acids with dihydroxy al- concrete, or mortar that determines its resistance to defor- cohols; commonly prepared for application by mixing mation or ease of molding. with a vinyl-group monomer and free-radical catalysts at plasticity index—see index, plasticity. ambient temperatures and used as binders for resin mor- plasticize—to produce plasticity or to render plastic. tars and concretes, fiber laminates (mainly glass), adhe- plasticizer—a material that increases the plasticity of a fresh sives, and the like. (See also concrete, polymer.) cement paste, mortar, or concrete. polyethylene—a thermoplastic high-molecular-weight or- plate— ganic compound used in formulating protective coatings 1. in formwork for concrete: a flat, horizontal member or, in sheet form, as a protective cover for concrete surfac- either at the top or bottom, or both, of studs or posts; a es during the curing period, or to provide a temporary en- mud sill if on the ground (see also mud sill); and closure for construction operations. 2. in structural design: a member, the depth of which is polymer—the product of polymerization; more commonly a substantially less than its length and width. (See also rubber or resin consisting of large molecules formed by plate, flat and load-transfer assembly.) polymerization. plate, deformed—a flat piece of metal, thicker than 1/4 polymer concrete—see concrete, polymer. in. (6 mm), having horizontal deformations or corru- polymer-cement concrete—see concrete, polymer-cement. gations; used in construction to form a vertical joint polymerization—the reaction in which two or more molecules and provide a mechanical interlock between adjacent of the same substance combine to form a compound con- sections. taining the same elements and in the same proportions but plate, flat—a flat slab without column capitals or drop of higher molecular weight. panels. (See also slab, flat.) polystyrene resin—see resin, polystyrene. plate, folded— polysulfide coating—see coating, polysulfide. 1. a framing assembly composed of sloping slabs in a polyurethane—reaction product of an isocyanate with any hipped or gabled arrangement; and of a wide variety of other compounds containing an active 2. prismatic shell with open polygonal section. hydrogen group; used to formulate tough, abrasion-resis- plum—a large random-shaped stone dropped into freshly tant coatings. placed mass concrete to economize on the amount of the polyvinyl acetate—colorless, permanently thermoplastic other concrete ingredients. (See also concrete, cyclope- resin; usually supplied as an emulsion or water-dispers- an.) ible powder characterized by flexibility, stability towards plumb—vertical or to make vertical. light, transparency to ultraviolet rays, high dielectric pneumatic feed—see feed, pneumatic. strength, toughness, and hardness; the higher the degree pneumatically applied mortar—see shotcrete. of polymerization, the higher the softening temperature; point count method—method for determination of the vol- may be used in paints for concrete. umetric composition of a solid by observation of the fre- polyvinyl chloride—a synthetic resin prepared by the poly- quency with which areas of each component coincide merization of vinyl chloride, used in the manufacture of with a regular system of points in one or more planes in- nonmetallic waterstops for concrete.

116R-48 ACI COMMITTEE REPORT prestress ponding—the creation and maintaining of a shallow pond of pozzolan, natural—a raw or calcined natural material water on the surface of a concrete slab to assist curing; ac- that has pozzolanic properties (for example, volcanic cidental or incidental occurrence of a shallow pond or tuffs or pumicites, opaline cherts and shales, clays, and ponds on a nominally flat surface of concrete; a condition diatomaceous earths). in which a horizontal slab deforms downward between pozzolanic—of or pertaining to a pozzolan. supports. pozzolanic-activity index—see index, pozzolanic-activity. popcorn concrete—see concrete, popcorn. pozzolanic reaction—see pozzolan. popout—the breaking away of small portions of a concrete preblended grout—see grout, preblended. surface due to localized internal pressure that leaves a shal- precast—a concrete member that is cast and cured in other low, typically conical, depression; small popouts leave than its final position; the process of placing and finishing holes up to 0.4 in (10 mm) in diameter; medium popouts precast concrete. (See also cast-in-place.) leave holes 0.4 to 2 in. (10 to 50 mm) in diameter; and large precast concrete—see concrete, precast. popouts leave holes greater than 2 in. (50 mm) in diameter. precast pile—see pile, precast. porosity—the ratio, usually expressed as a percentage of the precompressed zone—see zone, precompressed. volume of voids in a material to the total volume of the precuring period—see period, presteaming (preferred material including the voids. term). portland blast-furnace slag cement—see cement, port- prefire—to raise the temperature of refractory concrete un- land blast-furnace slag. der controlled conditions before placing it in service. portland cement—see cement, portland. preformed foam—see foam, preformed. portland-cement clinker—see clinker, portland-cement. premature stiffening—see set, false and set, flash. portland-cement concrete—see concrete. prepacked concrete—see concrete, preplaced-aggregate. portland-pozzolan cement—see cement, portland-poz- preplaced-aggregate concrete—see concrete, preplaced- zolan. aggregate and concrete, colloidal. pre-post-tensioning—a method of fabricating prestressed portlandite—the mineral, calcium hydroxide (Ca(OH)2); occurs naturally in Ireland; equivalent to a product of hy- concrete in which some of the tendons are pretensioned dration of portland cement. and a portion of the tendons are post-tensioned. porous fill—see drainage fill. preservation—the process of maintaining a structure in its present condition and arresting further deterioration. (See positive displacement—wet-mix shotcrete delivery equip- also rehabilitation; repair; and restoration.) ment in which the material is pushed through the material preset period—see period, presteaming (preferred term). hose in a solid mass by a piston or auger. preshrunk concrete (mortar, grout)—see concrete (mor- positive moment—see moment, positive. tar, grout), preshrunk. positive reinforcement—see reinforcement, positive. pressed edge—see edge, pressed. post—vertical formwork member used as a support; also pressure— known as shore, prop, or jack. pressure, form—lateral pressure acting on vertical or in- post shore—see shore, post. clined formed surfaces, resulting from the fluid-like post-tensioning—a method of prestressing reinforced con- behavior of the unhardened concrete confined by the crete in which tendons are tensioned after the concrete forms. has hardened. pressure, lateral—see pressure, form. post-tensioning, bonded—post-tensioned construction in pressure line—locus of force points within a structure re- which the annular spaces around the tendons are grouted sulting from combined prestressing force and externally after stressing, thereby bonding the tendon to the concrete applied load. section. presteaming period—see period, presteaming. pot life—time interval after preparation during which a liq- prestress—to place a hardened concrete member or an as- uid or plastic mixture is to be used. sembly of units in a state of compression before applica- pouring (of concrete)—see placement and placing. tion of service loads; the stress developed by prestressing, power float—see float, rotary (preferred term). such as by pretensioning or post-tensioning. (See also Powers’ spacing factor—see factor, Powers’ spacing concrete, prestressed; steel, prestressing; pretension- (preferred term). ing; and post-tensioning.) pozzolan—a siliceous or siliceous and aluminous material prestress, effective—the prestressing force at a specific that in itself possesses little or no cementitious value but location in a prestressed-concrete member under the that will, in finely divided form and in the presence of effects of service dead load or total service load after moisture, chemically react with calcium hydroxide at or- losses of prestress have occurred. dinary temperatures to form compounds having cementi- prestress, final—see stress, final. tious properties; there are both natural and artificial prestress, initial—the prestressing stress (or force) ap- pozzolans. plied to the concrete at the time of stressing. pozzolan, artificial—materials such as fly ash and silica prestress, transverse—prestress that is applied at right fume. (See also fly ash, and silica fume.) angles to the longitudinal axis of a member or slab.

CEMENT AND CONCRETE TERMINOLOGY 116R-49 prestressed

prestressed concrete—see concrete, prestressed. process, dry-cast; process, packerhead; and tamp prestressing, nonsimultaneous—the post-tensioning of process.) tendons individually rather than simultaneously. process, wet—in the manufacture of cement, the process prestressing, partial—prestressing to a stress level such in which the raw materials are ground, blended, mixed, that, under design loads, tensile stresses exist in the pre- and pumped while mixed with water; the wet process is compressed tensile zone of the prestressed member. chosen where raw materials are extremely wet and prestressing steel—see steel, prestressing. sticky which would make drying before crushing and pretensioning—a method of prestressing reinforced con- grinding difficult. (See also process, dry.) crete in which the tendons are tensioned before the con- promoter—see catalyst (preferred term). crete has hardened. promoter, flow—substance added to coating to enhance pretensioning bed (or bench)—the casting bed on which brushability, flow, and leveling. pretensioned members are manufactured and which re- proof stress—see stress, proof. sists the pretensioning force prior to release. prop—see post and shore. primary crusher—see crusher, primary. proportional limit—see limit, proportional. primary nuclear vessel—interior container in a nuclear reac- proportion—to select proportions of ingredients to make tor designed for sustained loads and for working conditions. the most economical use of available materials to produce principal planes—see stress, principal. mortar or concrete of the required properties. (See also principal stress—see stress, principal. mixture.) probabilistic design—see design, probabilistic. protected paste volume—the portion of hardened cement probe, penetration—a device for obtaining a measure of the paste that is protected from the effects of freezing by resistance of concrete to penetration; customarily deter- proximity to an entrained air void. (See also factor, Phil- mined by the distance that a steel pin is driven into the leo and factor, spacing.) concrete from a special gun by a precisely measured ex- protection period—the required time during which the con- plosive charge. crete is maintained at or above a specific temperature to process— prevent freezing of the concrete or ensure the necessary process, centrifugal—a process for producing concrete strength of development. products, such as pipe, that uses an outer form that is ro- proving ring—see ring, proving. tated about a horizontal axis and into which concrete is psychrometer, sling— a psychrometer containing indepen- fed by a conveyor; also called spinning process. (See dently matched dry- and wet-bulb thermometers, suitably also concrete, centrifugally cast; process, dry-cast; mounted for manually swinging through the ambient air, to packerhead; process, tamp; and process, wet-cast.) simultaneously indicate dry- and wet-bulb temperatures. process, dry—in the manufacture of cement, the process pugmill—see mixer, horizontal-shaft (preferred term). in which the raw materials are ground, conveyed, pulse velocity—see velocity, pulse. blended, and stored in a dry condition. (See also pro- pulverized-fuel ash (pfa)—see fly ash (preferred term in cess, wet.) the U.S.; pulverized-fuel ash is used in the UK). process, dry-cast—a process for producing concrete pumice—a highly porous and vesicular lava usually of rela- products, such as pipe, using low-frequency high-am- tively high silica content composed largely of glass drawn plitude vibration to consolidate dry-mix concrete in into approximately parallel or loosely entwined fibers, the form. (See also centrifugal process; process, which themselves contain sealed vesicles. packerhead; tamp process; process, wet-cast.) pumicite—naturally occurring finely divided pumice and process, dry-tamp—see packing, dry. glass shards. process, packerhead—a process for producing concrete pump, concrete—an apparatus that forces concrete to the pipe that uses a rotating device that forms the interior placing position through a pipeline or hose. surface of the pipe as concrete is fed into the form pumped concrete—see concrete, pumped. from above. (See also centrifugal process; process, pumping (of pavements)—the ejection of water, or water dry-cast; tamp process; process, wet-cast.) and solid materials, such as clay or silt, along transverse process, tamp—a process for producing concrete prod- or longitudinal joints and cracks, and along pavement ucts, such as pipe, that uses direct mechanical action to edges caused by downward slab movement activated by consolidate the concrete by the action of tampers that the passage of loads over the pavement after the accumu- rise automatically as the form is rotated and filled with lation of free water on or in the base course, subgrade, or concrete from above. (See also process, centrifugal; subbase. process, dry-cast; process, packerhead; and pro- punching shear—failure of a base or slab when a heavily cess, wet-cast.) loaded column punches a hole through it. process, wet-cast—a process for producing concrete punching shear stress—shear stress calculated by diving items, such as pipe, that uses concrete having a mea- the load on the slab that is transferred to the column by the surable slump, generally placed from above, and con- product of the perimeter and the thickness of the base or solidated by vibration. (See also centrifugal process; cap or by the product of the perimeter taken at 1/2 the slab

116R-50 ACI COMMITTEE REPORT recycled

thickness away from the column and the thickness of the ratio, aggregate-cement—the ratio of cement to total ag- base or cap. gregate, either by mass or volume. punning—an obsolete term designating a light form of ram- ratio, Poisson’s—the absolute value of the ratio of trans- ming. (See also ramming and tamping.) verse (lateral) strain to the corresponding axial (longitudi- purlin—in roofs, a horizontal member supporting the com- nal) strain resulting from uniformly distributed axial mon rafters. (See also beam.) stress below the proportional limit of the material; the val- putty—a plaster composed of quicklime or hydrated lime ue will average approximately 0.2 for concrete and 0.25 and water with or without plaster of paris or sand. for most metals. pyrite—a mineral, iron disulfide (FeS2), that, if it occurs in raw mix—blend of raw materials, ground to desired fine- aggregate used in concrete, can cause popouts and dark ness, correctly proportioned, and blended ready for burn- brown or orange-colored staining. ing; such as that used in the manufacture of cement pycnometer—a vessel for determination of specific gravity clinker. of liquids or solids. Rayleigh wave—an ultrasonic surface wave in which the pyrometric cone—see cone, pyrometric. particle motion is elliptical and effective penetration is pyrometric-cone equivalent (PCE)—the number of that approximately one wavelength. cone whose tip would touch the supporting plaque simul- reaction— taneously with that of a cone of the refractory material be- reaction, alkali-aggregate—chemical reaction in either ing investigated when tested in accordance with a mortar or concrete between alkalies (sodium and po- specified procedure such as ASTM C 24. tassium) from portland cement or other sources and certain constituents of some aggregates; under certain Q conditions, deleterious expansion of concrete or mor- tar may result. quality assurance—actions taken by an owner or represen- reaction, alkali-carbonate rock—the reaction between tative to provide and document assurance that what is be- the alkalies (sodium and potassium) in portland ce- ing done and what is being provided are in accordance ment and certain carbonate rocks, particularly calcitic with the applicable standards of good practice and fol- dolomite and dolomitic limestones, present in some lowing the contract documents for the work. aggregates; the products of the reaction may cause ab- quality control—actions taken by a producer or contractor normal expansion and cracking of concrete in service. to provide and document control over what is being done reaction, alkali-silica—the reaction between the alkalies and what is being provided so that the applicable stan- (sodium and potassium) in portland cement and certain dards of good practice and the contract documents for the siliceous rocks or minerals, such as opaline chert, work are followed. strained quartz, and acidic volcanic glass, present in quicklime—calcium oxide (CaO). some aggregates; the products of the reaction may quick set—see stiffening, early (preferred term). cause abnormal expansion and cracking of concrete in service. R reaction, endothermic—a chemical reaction that occurs with the absorption of heat. R-value—see resistance, thermal. reaction, exothermic—a chemical reaction that occurs raft foundation—see foundation, raft. with the evolution of heat. rail-steel reinforcement—see reinforcement, rail-steel. reaction, pozzolanic—see pozzolan. rake classifier—machine for separating coarse and fine par- reaction, subgrade—see contact pressure and coeffi- ticles of granular material temporarily suspended in wa- cient of subgrade reaction. ter; the coarse particles settle to the bottom of a vessel and reactive aggregate—see aggregate, reactive. are scraped up an incline by a set of blades, the fine par- reactive silica material—several types of materials that re- ticles remaining in suspension to be carried over the edge act at high temperatures with portland cement or lime dur- of the classifier. ing autoclaving, includes pulverized silica, natural raker—a sloping brace for a shore head. pozzolan, and fly ash. raked joint—see joint, raked. reactivity (of aggregate), alkali—susceptibility of aggre- raker pile—see pile, batter (preferred term). gate to alkali-aggregate reaction. raking pile—see pile, batter (preferred term). ready-mixed concrete—see concrete, ready-mixed. ramming—a form of heavy tamping of concrete, grout, or rebar—colloquial term for reinforcing bar. (See also rein- the like by means of a blunt tool forcibly applied. (See forcement.) also pack, dry; punning; and tamping.) rebound—aggregate and cement, or wet shotcrete, that random ashlar—see masonry, ashlar (preferred term). bounces away from the surface against which shotcrete is ranger—see wale (preferred term). being projected. ratio, A/F—the molar or mass ratio of aluminum oxide rebound hammer—see hammer, rebound. (Al2O3) to iron oxide (Fe2O3), as in portland cement. recycled concrete—see concrete, recycled.

CEMENT AND CONCRETE TERMINOLOGY 116R-51 refractories refractories—materials, usually nonmetallic, used to with- reinforcement, distribution-bar—small diameter bars, stand high temperatures. usually at right angles to the main reinforcement, in- refractoriness—in refractories, the property of being resis- tended to spread a concentrated load on a slab and to tant to softening or deformation at high temperatures. prevent cracking. refractory—resistant to high temperatures. reinforcement, dowel-bar—see dowel. refractory, castable—a packaged, dry mixture of hy- reinforcement, edge-bar—tension steel sometimes used draulic cement, generally calcium-aluminate cement, to strengthen otherwise inadequate edges in a slab and specially selected and proportioned refractory ag- without resorting to edge thickening. gregates that, when mixed with water, will produce re- reinforcement, expanded-metal fabric—see lath, ex- fractory concrete or mortar. panded-metal. refractory, neutral—a refractory that is resistant to reinforcement, four-way—a system of reinforcement in chemical attack by either acidic or basic substances. flat-slab construction comprising bands of bars paral- refractory aggregate—see aggregate, refractory. lel to two adjacent edges and also to both diagonals of refractory concrete—see concrete, refractory. a rectangular slab. refractory-insulating concrete—see concrete, refractory- reinforcement, heavy-edge—wire-fabric reinforcement insulating. for highway pavement slabs having one to four edge reglet—a groove in a wall to receive flashing. wires heavier than the other longitudinal wires. regulated-set cement—see cement, regulated-set. reinforcement, helical—steel reinforcement of hot- rehabilitation—the process of repairing or modifying a rolled bar or cold-drawn wire fabricated into a helix structure to a desired useful condition. (See also preser- (more commonly known as spiral reinforcement). vation; repair; and restoration.) reinforced concrete—see concrete, reinforced. reinforcement, high-strength—see steel, high-strength. reinforced masonry—see masonry, reinforced. reinforcement, hoop—a one-piece closed tie or continu- reinforcement—bars, wires, strands, or other slender mem- ously wound tie not less than No. 3 in size, the ends of bers that are embedded in concrete in such a manner that which have a standard 135 degree bend with a ten-bar they and the concrete act together in resisting forces. diameter extension, that encloses the longitudinal rein- reinforcement, auxiliary—in a prestressed member, forcement. any reinforcement in addition to that participating in reinforcement, lateral—transverse reinforcement, usu- the prestressing function. ally applied to ties, hoops, and spirals in columns or reinforcement, axle-steel—either plain or deformed re- column-like members. inforcing bars rolled from axle steel. reinforcement, longitudinal—reinforcement parallel to reinforcement bar—see reinforcement. the length of a concrete member or pavement. reinforcement, cold-drawn wire—steel wire made reinforcement, mesh—see fabric, welded-wire and re- from rods that have been hot rolled from billets cold- inforcement, welded-wire fabric. drawn through a die; for concrete reinforcement of a reinforcement, negative—steel reinforcement for nega- diameter not less than 0.080 in. (2 mm) nor greater tive moment. than 0.625 in. (16 mm). reinforcement, nonprestressed—reinforcing steel, not reinforcement, cold-worked steel—steel bars or wires subjected to either pretensioning or post-tensioning. that have been rolled, twisted, or drawn at normal am- reinforcement, nonstructural—see reinforcement, bient temperatures. temperature. reinforcement, compression—reinforcement designed reinforcement, positive—reinforcement for positive to carry compressive stresses. (See also stress.) moment. reinforcement, corner—metal reinforcement for plaster at reentrant corners to provide continuity between two reinforcement, rail-steel—reinforcing bars hot-rolled intersecting planes; or concrete reinforcement used at from standard T-section rails. wall intersections or near corners of square or rectan- reinforcement, shear—reinforcement designed to resist gular openings in walls, slabs, or beams. shear or diagonal tension stresses. (See also dowel.) reinforcement, crack-control—reinforcement in con- reinforcement, shrinkage—reinforcement designed to crete construction designed to minimize opening of resist shrinkage stresses in concrete. cracks, often effective in limiting them to uniformly reinforcement, spiral—continuously wound reinforce- distributed small cracks. ment in the form of a cylindrical helix. (See also re- reinforcement, curtain—a mat of orthogonal reinforcing inforcement, helical.) steel in a member such as a wall; known as a double cur- reinforcement, temperature—reinforcement designed tain (of reinforcement) when a mat is at each face. to carry stresses resulting from temperature changes; reinforcement, deformed—metal bars, wire, or fabric also the minimum reinforcement for areas of members with a manufactured pattern of surface ridges that pro- that are not subjected to primary stresses or necessarily vide a locking anchorage with surrounding concrete. to temperature stresses.

116R-52 ACI COMMITTEE REPORT restoration

reinforcement, tension—reinforcement designed to resetting (of forms)—setting of forms separately for each carry tensile stresses such as those in the bottom of a successive lift of a wall to avoid offsets at construction simple beam. joints. reinforcement, transverse—reinforcement at right an- reshoring—the construction operation in which the original gles to the longitudinal reinforcement. shoring or posting is removed and replaced in such a man- reinforcement, twin-twisted bar—two bars of the same ner as to avoid deflection of the shored element or damage nominal diameter twisted together. to partially cured concrete. reinforcement, two-way—reinforcement arranged in residual deformation—see creep, nonrecoverable. bands of bars at right angles to each other. resilience—the work done per unit volume of a material in reinforcement, web—reinforcement placed in a con- producing strain. crete member to resist shear and diagonal tension. resin—a natural or synthetic, solid or semisolid, organic ma- terial of indefinite and often high molecular weight hav- reinforcement, welded—reinforcement joined together ing a tendency to flow under stress, usually has a by welding. softening or melting range, and usually fractures con- reinforcement, welded-wire fabric—welded-wire fab- choidally. ric in either sheets or rolls, used to reinforce concrete. resin, acrylic—one of a group of thermoplastic resins reinforcement, woven-wire—see fabric, welded-wire formed by polymerizing the esters or amides of acrylic (preferred term). acid used to make polymer-modified concrete and reinforcement displacement—movement of reinforcing polymer concretes; also used in concrete construction steel from its specified position in the forms. as a bonding agent, surface sealer, or an integral con- reinforcement ratio—ratio of the effective area of the crete component. reinforcement to the effective area of the concrete at any resin, phenolic—a class of synthetic, oil-soluble resins section of a structural member. (See also percentage of (plastics) produced as condensation products of phe- reinforcement.) nol, substituted phenols and formaldehyde, or some relative humidity—the ratio of the quantity of water vapor similar aldehyde that may be used in paints for con- actually present to the amount present in a saturated atmo- crete. sphere at a given temperature; expressed as a percentage. resin, polystyrene—synthetic resins, varying from color- release agent—see agent, release. less to yellow, formed by the polymerization of styrene release, partial—release into a prestressed-concrete mem- on heating with or without catalysts, that may be used ber of a portion of the total prestress initially held wholly in paints for concrete, or for making sculptured molds, in the prestressed reinforcement. or as insulation. remoldability—the readiness with which freshly mixed resin concrete—see concrete, polymer (preferred term). concrete responds to a remolding effort such as jigging or resin mortar—see concrete, polymer. vibration, causing it to reshape its mass around reinforce- resins, epoxy—a class of organic chemical bonding systems ment and to conform to the shape of the form. (See also used in the preparation of special coatings or adhesives flow.) for concrete or as binders in epoxy-resin mortars and con- cretes. remolding test—see test, remoldability. resistance refractory aggregate—see aggregate, refractory. render—to apply a coat of mortar by a trowel or float. resistance, abrasion—ability of a surface to resist being repair—to replace or correct deteriorated, damaged, or worn away by rubbing and friction. faulty materials, components, or elements of a structure. resistance, fire—the property of a material or assembly (See also preservation; rehabilitation; and restoration.) to withstand fire or give protection from it; as applied repeatability—variability among replicate test results ob- to elements of buildings, it is characterized by the abil- tained on the same material within a single laboratory by ity to confine a fire or, when exposed to fire, to contin- one operator; a quantity that will be exceeded in only ue to perform a given structural function, or both. about 5% of the repetitions by the difference, taken in ab- resistance, penetration—the resistance, usually ex- solute value, of two randomly selected test results ob- pressed in lb/in.2 (psi) or megapascals (MPa), of either tained in the same laboratory on a given material; in use mortar or cement paste to penetration by a plunger or of the term, variable factors should be specified. needle under standard conditions, such as to determine repost—see reshoring. time of setting. reproducibility—variability among replicate test results resistance, skid—a measure of the frictional characteris- obtained on the same material in different laboratories; a tics of a surface. quantity that will be exceeded in only approximately 5% resistance, sulfate—ability of concrete or mortar to with- of the repetitions by the difference, taken in absolute val- stand sulfate attack. (See also sulfate attack.) ue, of two single test results made on the same material in resistance, thermal—the reciprocal of thermal conduc- two different, randomly selected laboratories; in use of tance expressed by the symbol R. the term, variable factors should be specified. restoration—the process of re-establishing the materials, required strength—see strength, required. form, and appearance of a structure to those of a particular

CEMENT AND CONCRETE TERMINOLOGY 116R-53 restraint

era of the structure. (See also preservation; rehabilita- ring, proving—a device for calibrating load indicators of tion; and repair.) testing machines, consisting of a calibrated elastic ring restraint (of concrete)—restriction of free movement of and a mechanism or device for indicating the magnitude fresh or hardened concrete following completion of plac- of deformation under load. ing in formwork or molds or within an otherwise confined rock pocket—a porous, mortar-deficient portion of hard- space; restraint can be internal or external and may act in ened concrete consisting primarily of coarse aggregate one or more directions. and open voids; caused by leakage of mortar from the retardation—reduction in the rate of either hardening, setting, form, separation (segregation) during placement, or insuf- or both, that is, an increase in the time required to reach time ficient consolidation. (See also honeycomb.) of initial and final setting or to develop early strength of rod—sharp-edged cutting screed used to trim shotcrete to fresh concrete, mortar, or grout. (See also retarder.) forms or ground wires. (See also screed.) retarder—an admixture that delays the setting of cement rod, dowel—see dowel (preferred term). paste and mixtures, such as mortar or concrete, containing rod, pencil—plain metal rod of about 1/4 in. (6 mm) cement. (See also admixture, retarding.) diameter. retarder, surface—a retarder applied to the contact surface rod, tamping—a straight steel rod of circular cross-sec- of a form or to the surface of newly placed concrete to de- tion and having one or both ends rounded to a hemi- lay setting of the cement, to facilitate construction joint spherical tip. cleanup, or to facilitate production of exposed-aggregate rod, tie—see tie, form and tieback. finish. rodability—the susceptibility of fresh concrete or mortar to retarding admixture—see admixture, retarding. consolidation by means of a tamping rod. retemper—to add water and remix concrete or mortar to re- rod buster (colloquial)—one who installs reinforcement for store workability to a condition in which the mixture is concrete. placeable or usable. (See also temper.) rodding—consolidation of concrete by means of a tamping reveal (n.)—the vertical surface forming the side of an open- rod. (See also rod; rodability; and tamping.) ing in a wall, as for a window or door; depth of exposure rodding, dry—in measurement of the mass per unit volume of aggregate in an exposed aggregate finish. (See also ex- of coarse aggregates, the process of consolidating dry ma- posed-aggregate finish.) terial in a calibrated container by rodding under standard- revibration—one or more applications of vibration to fresh ized conditions. concrete after completion of placing and initial consolida- rod mill—see mill, rod. tion but preceding initial setting of the concrete. roller-compacted concrete—see concrete, roller-com- revolving-blade (or paddle) mixer—see mixer, open-top. pacted. roller compaction—a process for compacting concrete us- rheology—the science dealing with flow of materials, in- ing a roller, often a vibratory roller. cluding studies of deformation of hardened concrete, the rolling—the use of heavy metal or stone rollers on terrazzo handling and placing of freshly mixed concrete, and the topping to extract excess matrix. behavior of slurries, pastes, and the like. Roman cement—see cement, Roman. rib—one of a number of parallel structural members backing roof, barrel-vault—a thin concrete roof in the form of a part sheathing; the portion of a T-beam which projects below of a cylinder. the slab; in deformed reinforcing bars, the deformations or roof insulation—see insulation, roof. the longitudinal parting ridge. room, fog—see moist room (preferred term). ribbed panel—see panel, ribbed. Rosiwal method—see linear-traverse method. ribbed slab—see panel, ribbed. rotary float (also called power float)—see float, rotary. ribbon—a narrow strip of wood or other material used in rotary kiln—see kiln, rotary. formwork. rough grind—the initial operation in which coarse abrasives ribbon loading—see loading, ribbon. are used to reduce the projecting stone chips in hardened rich concrete—see concrete, rich. terrazzo down to a level surface. rich mixture—a concrete mixture containing a high propor- rout—to deepen and widen a crack to prepare it for patching tion of cement. or sealing. rider cap—see cap, pile. rub brick—see brick, rubbing (preferred term). rigid frame—see frame, rigid. rubbing brick—see brick, rubbing. rigid pavement—see pavement, rigid. rubbed finish—see finish, rubbed. rigidity, flexural—a measure of stiffness of a member, indi- rubber set—see set, false (preferred term). cated by the product of modulus of elasticity and moment rubble—rough stones of irregular shape and size, broken of inertia divided by the length of the member. from larger masses by geological processes or by quarry- ring, air—perforated manifold in nozzle of wet-mix shot- ing; concrete reduced to irregular fragments, as by demo- crete equipment through which high pressure air is intro- lition or natural catastrophe. duced into the material flow. rubble concrete—see concrete, rubble.

116R-54 ACI COMMITTEE REPORT sand runway—decking over the area of concrete placement, usually      $   ( #.  #  ( #& of movable panels and supports, on which buggies of con- ( $    " 

  crete travel to points of placement. Note: the definitions are alternatives to be applied under rupture modulus—see modulus of rupture. differing circumstances. Definition 1 is applied to an rupture strength—see modulus of rupture. entire aggregate either in a natural condition or after rustic or washed finish—see finish, rustic or washed. processing. Definition 2 is applied to a portion of an rustication—a groove in a concrete surface. aggregate. Requirements for properties and grading rustication strip—see strip, rustication. should be stated in the specifications. Fine aggregate produced by crushing rock, gravel, or slag is commonly S known as manufactured sand. sand, graded standard—see sand, standard. sack—see bag (of cement) (preferred term). sand, manufactured—see sand. sack rub—a finish for formed concrete surfaces, designed sand, natural—sand resulting from natural disintegra- to produce even texture and fill pits and air holes; after tion and abrasion of rock. (See also sand and aggre- dampening the surface, mortar is rubbed over the surface, gate, fine.) then, before the surface dries, a mixture of dry cement sand, sharp—coarse sand consisting of particles of angular and sand is rubbed over it with either a wad of burlap or shape. a sponge-rubber float to remove surplus mortar and fill sand, standard—silica sand, composed almost entirely voids. (See also surface air voids and finish, rubbed.) of naturally rounded grains of nearly pure quartz, used safe leg load—see load, safe leg. for preparing mortars in the testing of hydraulic ce- ments. sagging—see sloughing (preferred term). Note: standard sand is produced in two gradings. salamander—a portable source of heat, customarily oil- * 
      burning, used to heat an enclosure around or over newly   µ   $   placed concrete to prevent the concrete from freezing. 7 µ    * µ*  sample—either a group of units or portion of material taken,  respectively, from a larger collection of units or a larger    
     & quantity of material, that serves to provide information $)  7 µ    * that can be used as a basis for action on the larger collec- µ*   tion or quantity or on the production process; the term is sand, stone—fine aggregate resulting from the mechani- also used in the sense of a sample of observations. cal crushing and processing of rock. (See also aggre- sample, composite—sample obtained by blending two or gate, fine and sand.) more individual samples of a material. sandblast—a system of cutting or abrading a surface such as sampling, continuous—sampling without interruptions concrete by a stream of sand ejected from a nozzle at high throughout an operation or for a predetermined time. speed by compressed air; often used for cleanup of hori- sampling, intermittent—sampling successively for limited zontal construction joints or for exposure of aggregate in periods of time throughout an operation or for a predeter- architectural concrete. mined period of time; the duration of sampling periods sand box (or sand jack)—a tight box filled with clean, dry, and the intervals are not necessarily regular and are not sand on which rests a tight-fitting timber plunger that sup- specified. ports the bottom of posts used in centering; removal of a sampling plan— plug from a hole near the bottom of the box permits the 1. a procedure that specifies the number of units of prod- sand to run out when it is necessary to lower the centering. uct from a lot that is to be inspected to establish ac- sand-coarse aggregate ratio—ratio of fine-to-coarse aggre- ceptability of the lot; and gate in a batch of concrete, by mass or by volume. 2. a prearranged program stipulating locations and pro- sand equivalent—a measure of the relative proportions of cedures for securing samples of a material for testing detrimental fine dust, claylike material or both in soils or purposes, for example, as concrete in construction or fine aggregate. aggregates in a quarry, pit, or stockpile. sand jack—see sand box. sand— sand-lightweight concrete—see concrete, sand-light- *  %       weight.         sand-lime brick—see brick, calcium-silicate (preferred       µ  term).   %   ( %   sand plate—a flat steel plate or strip welded to the legs of  $  (#.# (#( & bar supports for use on compacted soil. $    !  sand pocket—a zone in concrete or mortar containing fine     (    aggregate with little or no cement.        µ sand streak—a streak of exposed fine aggregate in the sur-    %   ( % & face of formed concrete, caused by bleeding.

CEMENT AND CONCRETE TERMINOLOGY 116R-55 sanded sanded grout—see grout, sanded. volves loss of coarse aggregate particles as well as mortar sandstone—a cemented or otherwise indurated sedimentary generally to a depth greater than 20 mm. rock composed predominantly of sand grains. scalper—a sieve for removing oversize particles. sandwich panel—see panel, sandwich. scalping—the removal, by sieving, of particles larger than a Santorin earth—a volcanic tuff originating on the Grecian specified size. island of Santorin and used as a pozzolan. scanning electron microscope (SEM)—see microscope, saponification—the alkaline hydrolysis of fats forming a soap; scanning electron (SEM). more generally, the hydrolysis of an ester by an alkali with scarf connection—see connection, scarf. the formation of an alcohol and a salt of the acid portion. scarf joint—see scarf connection (preferred term). saturated surface-dry—condition of an aggregate particle schist—a finely layered metamorphic rock that splits easily or other porous solid when the permeable voids are filled and in which the grain is coarse enough to permit identi- with water and no water is on the exposed surfaces. fication of the principal minerals. saturated surface-dry (SSD) particle density—the mass of Schmidt hammer—see hammer, rebound. the saturated surface-dry aggregate divided by its dis- scoria—vesicular volcanic ejecta of larger size, usually of placement volume in water or in concrete. basic composition and characterized by dark color; the saturation— material is relatively heavy and partly glassy, partly crys- talline; the vesicles do not generally interconnect. (See 1. in general: the condition of coexistence in stable equi- also aggregate, lightweight.) librium of either a vapor and a liquid or a vapor and scour—erosion of a concrete surface, exposing the aggregate. solid phase of the same substance at the same temper- scratch coat—see coat, scratch. ature; and screed— 2. as applied to aggregate or concrete: the condition such 1. to strike off concrete lying beyond the desired plane or that no more liquid can be held or placed within it. shape; and saturation, critical—a condition describing the degree 2. a tool for striking off the concrete surface, sometimes of filling by freezable water of a pore space in cement referred to as a strikeoff. paste or aggregate that affects the response of the ma- screed, cutting—sharp-edged tool used to trim shotcrete to terial to freezing; usually taken to be 91.7% because of the finished outline. (See also rod.) the 9% increase in volume of water undergoing the screed guide—firmly established grade strips or side forms change of state to ice. for unformed concrete that guide the strikeoff in produc- saturation, vacuum—a process for increasing the ing the desired plane or shape. amount of filling of the pores in a porous material, screed rails—see screed guide. such as lightweight aggregate, with a fluid, such as screed wire—see wire, ground. water, by subjecting the porous material to reduced screeding—the operation of forming a surface by the use of pressure while immersed in the fluid. screed guides and a strikeoff. (See also strikeoff.) saw cut—a cut in hardened concrete made using abrasive screen—production equipment for separating granular mate- blades or discs. rial according to size, using woven-wire cloth or other sim- sawdust concrete—see concrete, sawdust. ilar device with regularly spaced apertures of uniform size. sawed joint—see joint, sawed. screens, finish—vibrating screens (preferably horizontal) op- scab—a short piece of wood fastened to two formwork erated at a batching plant so that excessive amounts of sig- members to secure a butt joint. nificant undersize material are removed and delivered scaffolding—a temporary structure for the support of deck directly to the appropriate batcher bin without intermediate forms, cartways, or workers, or a combination of these, storage. such as an elevated platform for supporting workers, screw, adjustment—a leveling device or jack composed of tools, and materials; adjustable metal scaffolding is fre- a threaded screw and an adjusting handle; used for the quently adapted for shoring in concrete work. vertical adjustment of shoring and formwork. scale—the oxide formed on the surface of metal during heat- sealant—see sealant, joint. ing. (See also scaling.) sealant, joint—compressible material used to exclude water scaling—local flaking or peeling away of the near-surface and solid foreign materials from joints. portion of hardened concrete or mortar; also peeling or sealer—a liquid that is applied to the surface of hardened flaking of a layer from metal. (See also mill scale, peel- concrete to either prevent or decrease the penetration of ing, and spalling.) liquid or gaseous media, for example water, aggressive Note: light scaling of concrete does not expose coarse aggre- solutions, and carbon dioxide, during service exposer, gate; medium scaling involves loss of surface mortar to 5 that is absorbed by the concrete, is colorless, and leaves to 10 mm in depth and exposure of coarse aggregate; se- little or nothing visible on the surface. (See also coating vere scaling involves loss of surface mortar to 5 to 10 mm and compound, curing.) in depth with some loss of mortar surrounding aggregate sealing compound—see sealer. particles 10 to 20 mm in depth; very severe scaling in- seating—see deformation, anchorage.

116R-56 ACI COMMITTEE REPORT set secant modulus—see modulus of elasticity. separator, air—an apparatus that separates various size secondary crusher—see crusher, secondary. fractions of ground materials pneumatically; fine particles secondary moment—see moment, secondary. are discharged as product; oversized are returned to the secondary nuclear vessel—exterior container or safety mill as tailing. container in a nuclear reactor subjected to design load sequence-stressing loss—in post-tensioning, the elastic loss only once in its lifetime, if at all. in a stressed tendon resulting from the shortening of the section, transformed—a hypothetical section of one material member when additional tendons are stressed. arranged so as to have the same elastic properties as a sec- service dead load—see load, service dead. tion of two or more materials. service live load—see load, service live. section modulus—see modulus, section. service load— see load, service. segmental member—see member, segmental. set (n.)—the condition reached by a cement paste, mortar, or segregation—the differential concentration of the compo- concrete when it has lost plasticity to an arbitrary degree, nents of mixed concrete, aggregate, or the like, resulting usually measured in terms of resistance to penetration or in nonuniform proportions in the mass. (See also bleed- deformation; initial set refers to first stiffening; final set ing and separation.) refers to attainment of significant rigidity; also, strain re- maining after removal of stress. (See also set, perma- seismometer—instrument to detect linear (vertical, hori- nent.) zontal) or rotational displacement, velocity, or accelera- tion. set, false—the rapid development of rigidity in a freshly mixed portland cement paste, mortar, or concrete with- self-desiccation—the removal of free water by chemical re- out the evolution of much heat, in which rigidity can be action so as to leave insufficient water to cover the solid dispelled and plasticity regained by further mixing surfaces and cause a decrease in the relative humidity of without addition of water; premature stiffening, hesita- the system; applied to an effect occurring in sealed con- tion set, early stiffening, and rubber set are terms refer- cretes, mortars, and pastes. ring to the same phenomenon, but false set is the self-furring—metal lath or welded-wire fabric formed in preferred designation. (See also set, flash.) the manufacturing process to include means by which the set, final—a degree of stiffening of a mixture of cement material is held away from the supporting surface, thus and water greater than initial set, generally stated as an creating a space for “keying” of the insulating concrete, empirical value indicating the time in hours and min- plaster, or stucco. utes required for a cement paste to stiffen sufficiently self-furring nail—nails with flat heads and a washer or a to resist, to an established degree, the penetration of a spacer on the shank; for fastening reinforcing wire mesh weighted test needle; also applicable to concrete and and spacing it from the nailing member. mortar mixtures with use of suitable test procedures. self-stressing cement—see cement, expansive. (See also set, initial.) self-stressing concrete (mortar or grout)—see concrete set, flash—the rapid development of rigidity in a freshly (mortar or grout), self-stressing. mixed portland cement paste, mortar, or concrete, selvage—a finished edge of woven-wire screen cloth pro- characteristically with the evolution of considerable duced in the weaving process of the finer meshes. heat, in which rigidity cannot be dispelled nor can the semiautomatic batcher—see batcher. plasticity be regained by further mixing without the semiflexible joint—see joint, semiflexible. addition of water; also referred to as quick set or grab sensor—a device designed to respond to a physical stimulus set. (See also set, false.) (as temperature, illumination, and motion) and transmit a set, grab—see set, flash (preferred term). resulting signal for interpretation, measurement, or for set, hesitation—see set, false (preferred term). operating a control. set, initial—a degree of stiffening of a mixture of cement separation—the tendency, as concrete is caused to pass and water less than final set, generally stated as an em- from the unconfined ends of chutes or conveyor belts or pirical value indicating the time in hours and minutes similar arrangements, for coarse aggregate to separate required for cement paste to stiffen sufficiently to re- from the concrete and accumulate at one side; the tenden- sist to an established degree, the penetration of a cy, as processed aggregate leaves the ends of conveyor weighted test needle; also applicable to concrete or belts, chutes, or similar devices with confining sides, for mortar with use of suitable test procedures. (See also the larger aggregate to separate from the mass and accu- set, final.) mulate at one side; or the tendency for the solids to sepa- set, pack—see cement, sticky and set, warehouse. rate from the water by gravitational settlement. (See also set, permanent—inelastic elongation or shortening. bleeding and segregation.) set, rubber—see set, false (preferred term). separation joint—see joint, isolation (preferred term). set, stockhouse—see cement, sticky and set, ware- separation, heavy-media—a method in which a liquid or house. suspension of given specific gravity is used to separate set, warehouse— particles into a portion lighter than (those that float) and 1. the partial hydration of cement stored for a time and a portion heavier than (those that sink) the medium. exposed to atmospheric moisture; and

CEMENT AND CONCRETE TERMINOLOGY 116R-57 set-accelerating

2. mechanical compaction occurring during storage. shelly structure—see perlitic structure (preferred term). (See also cement, sticky.) shielding concrete—see concrete, shielding. set-accelerating admixture—see accelerator. shim—a strip of metal, wood, or other material employed to set-control addition—material, composed essentially of set base plates or structural members at the proper level calcium sulfate in any hydration state from CaSO4 to for placement of grout, or to maintain the elongation in ⋅ CaSO4 2H2O, interground with the clinker during manu- some types of post-tensioning anchorages. facture of cement to modify the setting time of the cement. shiplap—a type of joint in lumber or precast concrete made set-retarding admixture—see admixture, retarding and by using pieces having a portion of the width cut away on retarder. both edges, but on opposite sides, so as to make a flush setting time—time of setting (preferred term). joint with similar pieces. setting time, final—the time required for a freshly mixed shock, thermal—the subjection of newly hardened concrete cement paste, mortar, or concrete to achieve final set. to a rapid change in temperature that may be expected to (See also time, initial setting.) have a potentially deleterious effect. setting time, initial—the time required for a freshly shock load—see load, shock. mixed cement paste, mortar, or concrete to achieve shooting—placing of shotcrete. (See also gunning.) initial set. (See also time, final setting.) shoot wire—a wire running across the width of the sieve cloth, settlement—sinking of solid particles in grout, mortar, or as woven; also known as fill, filler, weft, or woof wire. fresh concrete, after placement and before initial set. (See shore—a temporary support for formwork and fresh con- also bleeding.) crete or for recently built structures that have not devel- settlement shrinkage—see shrinkage, settlement. oped full design strength; also called prop, tom, post, and settling—the lowering in elevation of sections of pavement strut. (See also L-head and T-head.) or structures due to their mass, the loads imposed on them, shore, pole—see shore, post. or shrinkage or displacement of the support. shore, post—individual vertical member used to support settling velocity—see velocity, settling. loads; also known as pole shore. shale—a laminated and fissile sedimentary rock, the constit- 1. adjustable timber single-post shore—individual uent particles of which are principally in clay and silt siz- timber used with a fabricated clamp to obtain ad- es; the laminations are bedding planes of the rock. justment; not normally manufactured as a complete shale, expanded (clay or slate)—lightweight vesicular ag- unit; gregate obtained by firing suitable raw materials in a kiln 2. fabricated single-post shore: Type I—single all- or on a sintering grate under controlled conditions. metal post with a fine-adjustment screw or device sharp sand—see sand, sharp. in combination with pin-and-hole adjustment or she bolt—see bolt, she. clamp; Type II: single or double wooden post mem- shear—an internal force tangential to the plane on which it bers adjustable by a metal clamp or screw and usu- acts. ally manufactured as a complete unit; and shearhead—assembled unit in the top of the columns of flat 3. timber single-post shore—timber used as a struc- slab or flat plate construction for transmitting loads from tural member for shoring support. slab to column. shore head—wood or metal horizontal member placed on and shear modulus—see modulus of rigidity. fastened to a vertical shoring member. (See also raker.) shear reinforcement—see reinforcement, shear. shoring—props or posts of timber or other material in com- shear strength—see strength, shear. pression used for the temporary support of excavations, shear stress—see stress, shear. formwork, or unsafe structures; the process of erecting shearwall—a wall portion of a structural frame intended to shores. resist lateral forces, such as earthquake, wind, and blast, shoring, horizontal—metal or wood load-carrying strut, acting in the plane of the wall. beam, or trussed section used to carry a shoring load from sheath—an enclosure in which post-tensioning tendons are one bearing point, column, frame, post, or wall to another; encased to prevent bonding during concrete placement. may be adjustable. (See also duct.) shoring layout—a drawing prepared before erection show- sheathing—the material forming the contact face of forms; ing arrangements of equipment for shoring. also called lagging or sheeting. short column—see column, short. sheet pile—see pile, sheet. shorten—to decrease in length. (See also contraction; elon- sheeting—see sheathing (preferred term). gation; and shrinkage.) shelf angles—structural angles with holes or slots in one leg shortening, elastic—in prestressed concrete, the shortening for bolting to the structure to support brick work, stone, or of a member that occurs immediately on the application terra cotta. of forces induced by prestressing. shelf life—the length of time packaged materials can be shotcrete—mortar or concrete pneumatically projected at stored under specified conditions and remain usable. high velocity onto a surface; also known as air-blown shell construction—see construction, shell. mortar, pneumatically applied mortar or concrete,

116R-58 ACI COMMITTEE REPORT size

sprayed mortar, and gunned concrete. (See also feed, sieve fraction—that portion of a sample that passes through pneumatic; positive displacement; shotcrete, dry-mix; a standard sieve of specified size and is retained by some and shotcrete, wet-mix.) finer sieve of specified size. shotcrete, dry-mix—shotcrete in which most of the mix- sieve number—a number used to designate the size of a ing water is added at the nozzle. sieve, usually the approximate number of openings per shotcrete, wet-mix—shotcrete in which the ingredi- linear inch; applied to sieves with openings smaller than ents, including water, are mixed before introduction 6.3 mm (1/4 in.). (See also mesh.) into the delivery hose; accelerator, if used, is normal- sieve size—nominal size of openings between cross wires of ly added at the nozzle. a testing sieve. shoulder—an unintentional offset in a formed concrete sur- significant (statistically significant)—values of a test sta- face usually caused by bulging or movement of formwork. tistic that lie outside of predetermined limits of test preci- shrink-mixed concrete—see concrete, shrink-mixed. sion and so taken to indicate a difference between shrinkage—decrease in either length or volume. populations. Note: may be restricted to the effects of moisture content or silica—silicon dioxide (SiO2). chemical changes. silica flour—very finely divided silica, a siliceous binder shrinkage, carbonation—shrinkage resulting from car- component that reacts with lime under autoclave curing bonation. conditions; prepared by grinding silica, such as quartz, to shrinkage, drying—shrinkage resulting from loss of a fine powder; also known as silica powder. moisture. silica fume—very fine noncrystalline silica produced in shrinkage, initial drying—the difference between the electric arc furnaces as a byproduct of the production of length of a specimen (molded and cured under stated elemental silicon or alloys containing silicon. (See also conditions) and its length when first dried to constant silica fume.) length, expressed as a percentage of the moist length. silica powder—see silica flour (preferred term). shrinkage, plastic—shrinkage that takes place before silicate—salt of a silicic acid. (See alite; belite; blast-fur- cement paste, mortar, grout, or concrete sets. nace slag; bredigite; celite; brick, calcium-silicate; hy- drate, calcium-silicate; concrete, siliceous-aggregate; shrinkage, settlement—a reduction in volume of con- clay; dicalcium silicate; clay, fire; fluosilicate; lime, hy- crete before the final set of cementitious mixtures, draulic hydrated; kaolin; larnite; melilite; smectite; caused by settling of the solids and displacement of Stratling’s compound; tobermorite; tricalcium sili- fluids. (See also shrinkage, plastic, and volume cate; vermiculite; and xonotlite.) change, autogenous.) siliceous-aggregate concrete—see concrete, siliceous-ag- shrinkage-compensating—a characteristic of grout, mor- gregate. tar, or concrete made using expansive cement in which silicon carbide—an artificial product (SiC), granules of volume increases after setting, and if properly elastically which may be embedded in concrete surfaces to increase restrained, induces compressive stresses that are intended resistance to wear or as a means of reducing skidding or to approximately offset the tendency of drying shrinkage slipping on stair treads or pavements; also used as an to induce tensile stresses. (See also cement, expansive.) abrasive in saws and drills for cutting concrete and ma- shrinkage-compensating cement—see cement, expansive. sonry, and as abrasive grit in a range of particle sizes. shrinkage-compensating concrete—see concrete, shrink- silicone—a resin, characterized by water-repellent proper- age-compensating. ties, in which the main polymer chain consists of alternat- shrinkage crack—see crack, shrinkage. ing silicon and oxygen atoms with carbon-containing side shrinkage cracking—see cracking, shrinkage. groups; silicones may be used in caulking or coating com- shrinkage limit—see limit, shrinkage. pounds or as admixtures for concrete. shrinkage loss—see loss, shrinkage. sill—see mud sill. shrinkage reinforcement—see reinforcement, shrinkage. 
 %  % (    ( shuttering—see formwork. #.)    µ  ! SI (Système International)—the modern metric system.    %#  #    (  µ (See ASTM E 380.)   side, pilaster—the form for the side surface of a pilaster per- simple beam—see beam, simple. pendicular to the wall. single-sized aggregate—see aggregate, single-sized. sieve—a metallic plate or sheet, a woven-wire cloth, or other single-stage curing—see curing, single-stage. similar device with regularly spaced apertures of uniform sinter—a ceramic material or mixture fired to less than com- size, mounted in a suitable frame or holder for use in sep- plete fusion, resulting in a coherent mass; also the process arating granular material according to size. involved. sieve analysis—see analysis, sieve. sintering—the formation of a porous mass of material by the sieve correction—correction of a sieve analysis to adjust for agglomeration of fine particles during particle fusion. deviation of sieve performance from that of standard cal- sintering grate—a grate on which material is sintered. ibrated sieves. size, nominal—see nominal maximum size (of aggregate).

CEMENT AND CONCRETE TERMINOLOGY 116R-59 skew skew back—sloping surface against which the end of an lay concrete evenly for highway paving or on slopes and arch rests, such as a concrete thrust block supporting inverts of canals, tunnels, and siphons; or may move ver- thrust of an arch bridge. (See also strip, chamfer.) tically to form walls, bins, or silos. skid resistance—see resistance, skid. sloped footing—see footing, sloped. slab—a molded layer of plain or reinforced concrete, flat, sloughing—subsidence of shotcrete, plaster, or the like, due horizontal (or nearly so), usually of uniform but some- generally to excessive water in the mixture; also called times of variable thickness, either on the ground or sup- sagging. ported by beams, columns, walls, or other framework. slugging—pulsating and intermittent flow of shotcrete (See also slab, flat and plate, flat.) material due to improper use of delivery equipment and slab, flat—a concrete slab reinforced in two or more di- materials. rections and having drop panels, column capitals or slump—a measure of consistency of freshly mixed concrete, both. (See also plate, flat.) mortar, or stucco equal to the subsidence measured to the slab, ribbed—see panel, ribbed. nearest 1/4 in. (6 mm) of the molded specimen immedi- slab bolster—see bolster, slab. ately after removal of the slump cone. slabjacking—the process of either raising concrete pave- slump cone—see cone, slump. ment slabs or filling voids under them, or both, by inject- slump loss—see loss, slump. ing a material (cementitious, noncementitious, or slump test—see test, slump. asphaltic) under pressure. slurry—a mixture of water and any finely divided insoluble slab-on-grade—a slab, continuously supported by ground, material, such as portland cement, slag, or clay in suspen- whose total loading when uniformly distributed would sion. impart a pressure to the grade or soil that is less than 50% slush grouting—see grouting, slush. of the allowable bearing capacity thereof; the slab may be smectite—a group of clay minerals, including montmorillo- of uniform or variable thickness, and it may include stiff- nite, characterized by a sheet-like internal atomic struc- ening elements such as ribs or beams; the slab may be ture; consisting of extremely finely-divided hydrous plain, reinforced, or prestressed concrete; reinforcement aluminum or magnesium silicates that swell on wetting, or prestressing steel may be provided to accommodate the shrink on drying, and are subject to ion exchange. effects of shrinkage and temperature or structural loading. snap tie—a proprietary concrete wall-form tie, the end of (Also referred to as slab-on-ground; slab-on-grade is the which can be twisted or snapped off after the forms have preferred term.) been removed. slab spacer—see spacer, slab. soaking period—see period, soaking. slab strip—see strip, middle (preferred term). soffit—the underside of a part or member of a structure, such slag—see blast-furnace slag. as a beam, stairway, or arch. slag cement—see cement, slag. soft particle—an aggregate particle possessing less than an slate—a fine-grained metamorphic rock possessing a well- established degree of hardness or strength as determined developed fissility (slaty cleavage), usually not parallel to by a specific testing procedure. the bedding planes of the rock. soil—a generic term for unconsolidated natural surface ma- sleeve—a pipe or tube passing through formwork for a wall terial above bedrock. or slab through which pipe, wires, or conduit can be soil, fine-grained—soil in which the smaller grain sizes passed after the forms have been stripped. predominate, such as fine sand, silt, and clay. sleeve, expansion—a tubular metal covering for a dowel bar soil, coarse-grained—soil in which the larger grain sizes, to allow its free longitudinal movement at a joint. such as sand and gravel, predominate. slender beam—see beam, slender. soil cement—a mixture of soil and measured amounts of slender column—see column, slender. portland cement and water, compacted to a high density. slenderness ratio—the effective unsupported length of a soil pressure—see contact pressure. uniform column divided by the least radius of gyration of soil stabilization—chemical or mechanical treatment de- the cross-sectional area. signed to either increase or maintain the stability of a mass slick line—end section of a pipeline used in placing concrete of soil or otherwise to improve its engineering properties. by pump which is immersed in the placed concrete and soldier—a vertical wale used to strengthen or align form- moved as the work progresses. work or excavations. sliding form—see slipform (preferred term). solid masonry unit—a unit whose net cross-sectional area sling psychrometer—see psychrometer, sling. in every plane parallel to the bearing surface is 75% or slip—movement occurring between steel reinforcement and more of its gross cross-sectional area measured in the concrete in stressed reinforced concrete, indicating an- same plane. chorage breakdown. solid masonry wall—see masonry wall, solid. slip, anchorage—see deformation, anchorage or slip. solid panel—see panel, solid. slipform—a form that is pulled or raised as concrete is solid-unit masonry—see masonry, solid-unit. placed; may move in a generally horizontal direction to solid volume—see volume, absolute.

116R-60 ACI COMMITTEE REPORT splice solubility—the amount of one material that will dissolve in or other appliance so as to form a thin, coarse-textured, another, generally expressed as mass percent, as volume continuous coating; as a preliminary treatment before ren- percent, or parts per 100 parts of solvent by mass or vol- dering, it assists bond of the undercoat to the background, ume at a specified temperature. improves resistance to rain penetration, and evens out the solution—a liquid consisting of at least two substances, one suction of variable backgrounds. (See also coat, dash- of which is a liquid solvent in which the other or others, bond and parge.) that may be either solid or liquid, are dissolved. specific gravity, absolute—ratio of the mass (referred to as solvent—a liquid in which another substance may be dis- vacuum) of a given volume of a solid or liquid at a stated solved. temperature to the mass (referred to as vacuum) of an sonic modulus—see modulus of elasticity, dynamic. equal volume of gas-free distilled water at a stated tem- sounding well—a vertical conduit in the mass of coarse ag- perature. gregate for preplaced-aggregate concrete, provided with specific gravity, apparent—the ratio of the mass of a continuous or closely spaced openings to permit entrance volume of the impermeable portion of a material at a of grout; the grout level is determined by means of a float stated temperature to the mass of an equal volume of on a measured line. distilled water at a stated temperature; soundness—the freedom of a solid from cracks, flaws, fis- specific gravity, bulk—the ratio of the mass of a volume sures, or variations from an accepted standard; in the case of a material (including the permeable and imperme- of a cement, freedom from excessive volume change after able voids in the material, but not including the voids setting; in the case of aggregate, the ability to withstand between particles of the material) at a stated tempera- the aggressive action to which concrete containing it ture to the mass of an equal volume of distilled water might be exposed, particularly that due to weather. at a stated temperature; and space, capillary—void space in concrete resembling micro- specific gravity, bulk (saturated-surface-dry)—the ra- scopic channels small enough to draw liquid water tio of the mass of a volume of a material (including the through them by the molecular attraction of the water ad- mass of water within the voids, but not including the sorbed on their inner surfaces. voids between particles) at a stated temperature to the spacer—device that maintains reinforcement in proper po- mass of an equal volume of distilled water at a stated sition; also a device for keeping wall forms apart at a giv- temperature. (See also density.) en distance before and during concreting. (See also specific gravity factor—the ratio of the mass of aggregates spreader.) (including moisture), as introduced into the mixer, to the spacer, slab—bar support and spacer for slab reinforcement; effective volume displaced by the aggregates. similar to slab bolster but without corrugations in top wire; specific heat—the amount of heat required per unit mass to no longer in general use. (See also bolster, slab.) cause a unit rise of temperature, over a small range of spacing factor—see factor, spacing. temperature. spading—consolidation of mortar or concrete by repeated specific surface—see surface, specific. insertion and withdrawal of a flat, spadelike tool. specification (in ASTM)—an explicit set of requirements to spall—a fragment, usually in the shape of a flake, detached be satisfied by a material, product, system, or service. from a larger mass by a blow, by the action of weather, by specimen—a piece or portion of a sample used to make a test. pressure, or by expansion within the larger mass; a small spectrophotometer—instrument for measuring the intensi- spall involves a roughly circular depression not greater ty of radiant energy of desired frequencies absorbed by at- than 20 mm in depth and 150 mm in any dimension; a oms or molecules; substances are analyzed by converting large spall may be roughly circular or oval or in some cas- the absorbed energy to electrical signals proportional to es elongate and is more than 20 mm in depth and 150 mm the intensity of radiation. (See also spectroscopy, infra- in greatest dimension. red and photometer, flame.) spalling—the development of spalls. spectroscopy, infrared—the use of a spectrophotometer for span—distance between the support reactions of members determination of infrared absorption spectra (2.5 to 18 µm carrying transverse loads. wave lengths) of materials; used for detection, determina- span-depth ratio—the numerical ratio of total span-to- tion, and identification especially of organic materials. member depth. spectroscopy, X-ray emission—see X-ray fluorescence. span, effective—the lesser of the two following distances: speed, agitating—the rate of rotation of the drum of a truck a) the distance between supports; or b) the clear distance mixer or agitator when used for agitating mixed concrete. between supports plus the effective depth of the beam or spinning—the essential factor of the process of producing slab. spun concrete. (See also concrete, spun.) span length—see span, effective. spiral reinforcement—see reinforcement, spiral. spandrel—that part of a wall between the head of a window spirally reinforced column—see column, spirally reinforced. and the sill of the window above it. splice—connection of one reinforcing bar to another by lap- spandrel beam—see beam, spandrel. ping, welding, mechanical couplers, or other means; con- spatterdash—a rich mixture of portland cement and coarse nection of welded-wire fabric by lapping; connection of sand; it is thrown onto a background by a trowel, scoop, piles by mechanical couplers.

CEMENT AND CONCRETE TERMINOLOGY 116R-61 splice

splice, contact—a means of connecting reinforcing bars the top of the tube and spills out of wall openings to make in which the bars are lapped and in direct contact. (See a conical pile surrounding the tube. also splice, lap.) staged grouting—see grouting, staged. splice, lap—a connection of reinforcing steel made by stain—discoloration by foreign matter. lapping the ends of bars. stalactite—a downward-pointing deposit formed as an ac- splice, welded-butt—a reinforcing bar splice made by cretion of mineral matter produced by evaporation of welding the butted ends. dripping water from the surface of rock or of concrete, split-batch charging—method of charging a mixer in which commonly shaped like an icicle. (See also stalagmite.) the solid ingredients do not enter the mixer together; ce- stalagmite—an upward-pointing deposit formed as an ac- ment, and sometimes different sizes of aggregate, may be cretion of mineral matter produced by evaporation of added separately. dripping water, projecting from the surface of rock or of split block—see split-face block. concrete, commonly roughly conical in shape. (See also split-face block—a concrete masonry unit with one or more stalactite.) faces purposely fractured to provide architectural effects standard curing—see curing, standard. in masonry wall construction. standard deviation—the root mean square deviation of in- splitting tensile strength—see strength, splitting tensile. dividual values from their average. splitting tensile test (diametral compression test)—a test standard fire test—the test prescribed by ASTM E 119. for tensile strength in which a cylindrical specimen is standard hook—a hook at the end of a reinforcing bar made loaded to failure in diametral compression applied along in accordance with a standard. the entire length. standard hooked bar—see bar, standard hooked. spray drying—a method of evaporating the liquid from a so- standard matched—tongue-and-groove lumber with the lution or dispersion by spraying it into a heated gas. tongue and groove offset rather than centered as in center spray lime—see lime, spray. matched lumber. (See also center matched.) standard sand—see sand, standard. sprayed concrete—see shotcrete (preferred term). standard time-temperature curve—the graphic time table sprayed mineral fiber—a blend of mineral fibers and inor- for application of temperature to a material or member for ganic binders to which water is added during the spraying the ASTM E 119 fire test. operation. static load—see load, static. sprayed mortar—see shotcrete. static modulus of elasticity—see modulus of elasticity, spread footing—a generally rectangular prism of concrete, static. larger in lateral dimensions than the column or wall it sup- stationary hopper—a container used to receive and tempo- ports, to distribute the load of a column or wall to the sub- rarily store freshly mixed concrete. grade. steam box—enclosure for steam-curing concrete products. spreader— (See also steam-curing room.) 1. a piece of lumber, usually about 1 by 2 in. (25 by 50 steam curing—see curing, steam. mm), cut to the thickness of a wall or other formed el- steam-curing cycle—the time interval between the start of ement and inserted in the form to hold it temporarily the temperature rise period and the end of the soaking pe- at the correct dimension against tension of form ties; riod or the cooling-off period; also a schedule indicating wires are usually attached to spreaders so they can be the duration of and the temperature range of the periods pulled up out of the forms as the pressure of concrete that make up the cycle. permits their removal; and steam-curing room—a chamber for steam curing of con- 2. a device consisting of reciprocating paddles, a revolv- crete products at atmospheric pressure. ing screw, or other mechanism for distributing con- steam kiln—see steam-curing room (preferred term). crete to required uniform thickness in a paving slab. stearic acid—a white crystalline fatty acid, obtained by sa- spreader, concrete—a machine, usually carried on side ponifying tallow or other hard fats containing stearin. forms or on rails parallel thereto, designed to spread (See also butyl stearate.) concrete from heaps already dumped in front of it, or steel— to receive and spread concrete in a uniform layer. steel, axle—steel from carbon-steel axles for railroad spreader, form—see spreader. cars. spud vibrator—see vibrator, spud. steel, billet—steel, either produced directly from ingots spun concrete—see concrete, centrifugally cast (preferred or continuously cast, made from properly identified term). heats of open-hearth, basic oxygen, or electric-furnace stabilizer—a substance that makes either a solution or sus- steel, or lots of acid Bessemer steel, and conforming to pension more stable, usually by keeping particles from specified limits of chemical composition. precipitating. steel, high-strength—steel with a high yield point; in the stacking tube—a slender, free-standing tubular structure case of reinforcing bars, 60,000 psi (414 MPa) and used to store granular materials; the material is loaded into greater. (See also steel, prestressing.)

116R-62 ACI COMMITTEE REPORT strength

steel, prestressing—high-strength steel used to prestress be measured conveniently in percent, in inches per inch, concrete; commonly seven-wire strands, single wires, in millimeters per millimeters, but preferably in mil- bars, rods, or groups of wires or strands. (See also pre- lionths. stress; concrete, prestressed; pretensioning, and strain, unit—deformation of a material expressed as the ra- post-tensioning.) tio of linear unit deformation to the distance within which steel sheet—cold-formed sheet or strip steel shaped as a that deformation occurs. structural member for the purpose of carrying the live and strand—a prestressing tendon composed of a number of dead loads in lightweight concrete roof construction. wires twisted above the center wire or core. steel temperature—see reinforcement, temperature. strand, indented—strand having machine-made surface in- steel trowel—see trowel. dentations intended to improve bond. stem bars—see bars, stem. strand grip—a device used to anchor strands. stepped footing—see footing, stepped. strand wrapping—application of high tensile strand, sticky cement—see cement, sticky. wound under tension by machines, around circular con- stiffback—see strongback (preferred term). crete or shotcrete walls, domes, or other tension-resisting stiffening, early—the early development of an abnormal re- structural components. duction in the working characteristics of a hydraulic-ce- stratification—the separation of overwet or overvibrated ment paste, mortar, or concrete, which may be further concrete into horizontal layers with increasingly lighter described as false set, quick set, or flash set. material toward the top; water, laitance, mortar, and stiffening, premature—see set, false and set, flash (pre- coarse aggregate tend to occupy successively lower posi- ferred term). tions in that order; a layered structure in concrete result- stiffness—resistance to deformation. ing from placing of successive batches that differ in stiffness factor—see factor, stiffness. appearance; occurrence in aggregate stockpiles of layers stirrup—reinforcement used to resist shear and diagonal of differing grading or composition; a layered structure in tension stresses in a structural member; typically a steel a rock foundation. bar bent into a U or box shape and installed perpendicular Stratling’s compound—dicalcium aluminate monosilicate- to or at an angle to the longitudinal reinforcement, and 8-hydrate, a compound that has been found in reacted properly anchored; lateral reinforcement formed of indi- lime-pozzolan and cement-pozzolan mixtures. vidual units, open or closed, or of continuously wound re- strength—a generic term for the ability of a material to resist inforcement. strain or rupture induced by external forces. (See also stockhouse set—see cement, sticky and set, warehouse. strength, compressive; strength, fatigue; strength, stoichiometric— flexural; strength, shear; strength, splitting tensile; 1. characterized by or being a proportion of substances or strength, tensile; strength, ultimate; and strength, energy in a specific chemical reaction in which there yield.) is no excess of any reactant or product; and 2. proportioning based on atomic or molecular weight. strength, bond—resistance to the separation of mortar stone, cast—concrete or mortar cast into blocks or small and concrete from reinforcing and other materials with slabs in special molds so as to resemble natural building which it is in contact; a collective expression for forces stone. such as adhesion, friction due to shrinkage, and longi- tudinal shear in the concrete engaged by the bar defor- stone, crushed—the product resulting from the artificial mations that resist separation. crushing of rocks, boulders, or large cobblestones, sub- stantially all faces of which possess well-defined edges strength, cold—the compressive or flexural strength of resulting from the crushing operation. (See also aggre- refractory concrete determined before drying or firing. gate, coarse.) strength, compressive—the measured maximum resis- stone sand—see sand, stone. tance of a concrete or mortar specimen to axial com- storage hopper—see stationary hopper. pressive loading; expressed as force per unit cross- straightedge— sectional area; or the specified resistance used in de- 1. a rigid, straight piece of either wood or metal used to sign calculations. strikeoff or screed a concrete surface to proper grade, strength, cube—the load per unit area at which a stan- or to check the planeness of a finished grade (see also dard cube fails when tested in a specified manner. rod; screed; and strikeoff); and strength, cylinder—see strength, compressive and 2. a highway tool for truing surfaces instead of a bull strength, splitting tensile. float. strength, design—nominal strength of a member multi- straight-line theory—an assumption in reinforced concrete plied by a strength-reduction (φ) factor. (See also analysis according to which the strains and stresses in a strength, nominal and factor, phi.) member under flexure are assumed to vary in proportion strength, dried—the compressive or flexural strength of to the distance from the neutral axis. refractory concrete determined within three hours after strain—the change in length, per unit of length, in a linear first drying in an oven at 220 to 230 F (105 to 110 C) dimension of a body; a dimensionless quantity that may for a specified time.

CEMENT AND CONCRETE TERMINOLOGY 116R-63 strength

strength, early—strength of concrete or mortar usually as strength, transverse—see strength, flexural and modu- developed at various times during the first 72 h after lus of rupture. placement. strength, ultimate—an obsolete term; see strength, strength, fatigue— the greatest stress that can be sus- nominal. tained for a given number of stress cycles without fail- strength, yield—the engineering stress at which a material ure. exhibits a specific limiting deviation from the propor- strength, fired—the compressive or flexural strength of tionality of stress to strain. refractory concrete determined upon cooling after first strength-design method—a design method that requires firing to a specified temperature for a specified time. service loads to be increased by specified load factors and strength, flexural—the property of a material or a struc- computed nominal strengths to be reduced by the speci- tural member that indicates its ability to resist failure in fied phi (φ) factors. bending; in concrete flexural members, the stress at strength-reduction factor—see factor, strength-reduction. which a section reaches its maximum usable bending stress—intensity of internal force (that is, force per unit area) capacity; for under-reinforced concrete flexural mem- exerted by either of two adjacent parts of a body on the oth- bers, the stress at which the compressive strain in the er across an imagined plane of separation; when the forces concrete reaches 0.003; for over-reinforced concrete are parallel to the plane, the stress is called shear stress; flexural members, the stress at which the compressive when the forces are normal to the plane, the stress is called stress reaches 85% of the cylinder strength of the con- normal stress; when the normal stress is directed toward crete; for unreinforced-concrete members, the stress at the part on which it acts, it is called compressive stress; which the concrete tensile strength reaches the modu- when the normal stress is directed away from the part on lus of rupture. (See also modulus of rupture.) which it acts, it is called tensile stress. strength, nominal—strength of a member or cross sec- stress, allowable—maximum permissible stress used in tion calculated in accordance with provisions and as- the design of members of a structure and based on a sumptions of the strength design method before factor of safety against rupture or yielding of any type. application of any strength-reduction (Φ) factor. stress, anchorage bond—the bar forces divided by the strength, nominal flexural—the flexural strength of a product of the bar perimeter or perimeters and the em- member or cross section calculated in accordance with bedment length. provisions and assumptions of the strength-design stress, bond—the force of adhesion per unit area of con- method before application of any strength-reduction tact between two bonded surfaces, such as concrete (Φ) factor. and reinforcing steel, or any other material, such as foun- strength, nominal shear—the shear strength of a mem- dation rock; shear stress at the surface of a reinforcing ber or cross section calculated in accordance with pro- bar, preventing relative movement between the bar and visions and assumptions of the strength-design method the surrounding concrete when the bar carries tensile before application of any strength-reduction (Φ) factor. force. strength, offset yield—the stress at which the strain ex- stress, compressive—see stress. ceeds, by a specified amount, an extension of the ini- stress, effective—see prestress, effective. tially proportional part of the stress-strain curve; stress, final—in prestressed concrete, the stress that ex- expressed either as a percentage of the original gage ists after substantially all losses have occurred. length in conjunction with the strength value (yield stress, jacking—the maximum stress occurring in a pre- strength at... percent offset =...psi) or as force per unit stressed tendon during stressing. area ([psi] or [MPa].) stress, mean—the average of the maximum and mini- strength, required—strength of a member or cross sec- mum stress in one cycle of fluctuating loading (as in a tion required to resist factored loads or related internal fatigue test); tensile stress is considered positive and moments and forces in such combinations as are stipu- compressive stress, negative. lated in the applicable code or specification. stress, normal— the stress component that is perpendic- strength, shear—the maximum shearing stress a flexural ular to the plane on which the force is applied; desig- member can support at a specific location as controlled nated tensile if the force is directed away from the by the combined effects of shear forces and bending plane and compressive if the force is directed toward moment. the plane. (See also stress.) strength, splitting tensile—tensile strength of concrete stress, principal—maximum and minimum stresses at determined by a splitting tensile test. any point acting at right angles to the mutually perpen- strength, tensile—maximum unit stress that a material is dicular planes of zero shearing stress, which are desig- capable of resisting under axial tensile loading; based on nated as the principal planes. the cross-sectional area of the specimen before loading. stress, proof—stress applied to materials sufficient to strength, transfer—the concrete strength required before produce a specified permanent strain; a specific stress stress is transferred from the stressing mechanism to to which some types of tendons are subjected in the the concrete. manufacturing process as a means of reducing the de-

116R-64 ACI COMMITTEE REPORT subaqueous

formation of anchorage, reducing the relaxation of rounded or flat chamfer or to form a rustication; also steel, or ensuring that the tendon is sufficiently strong. called cant strip, fillet, dummy joint, and skew back. stress, shear—the stress component acting tangentially strip, grade—usually a thin strip of wood tacked to the to a plane. inside surface of forms at the elevation to which the stress, temperature—stress in a structure or a member top of the concrete lift is to rise, either at a construction due to changes or differentials in temperature in the joint or the top of the structure. structure or member. strip, kick—see kicker. stress, temporary—a stress that may be produced in a strip, middle—in flat-slab framing, the slab portion that precast-concrete member or in a component of a pre- occupies the middle half of the span between columns. cast-concrete member during fabrication or erection, (See also column strip.) or in cast-in-place concrete structures due to construc- strip, panel—a strip extending across the length or width tion or test loadings. of a flat slab for structural design and construction or stress, tensile—see stress. for architectural purposes. stress, thermal—see stress, temperature. strip, rustication—a strip of wood or other material at- stress, torsional—the shear stress on a transverse cross tached to a form surface to produce a groove or rusti- section resulting from a twisting action. cation in the concrete. stress, ultimate shear—see strength, shear. strip, slab—see strip, middle (preferred term). stress, working—maximum permissible design stress strip, wrecking—small piece or panel fitted into a form- using working-stress design methods. work assembly in such a way that it can be easily re- stress corrosion—corrosion of a metal either initiated or ac- moved ahead of main panels or forms, making it easier celerated by stress. to strip those major form components. stress-corrosion cracking—see cracking, stress-corrosion. strip footing—see footing, continuous. stress relaxation—the time-dependent decrease in stress in strip foundation—see foundation, strip. a material held at constant strain. (See also flow, plastic stripper—a liquid compound formulated to remove coatings and creep.) by either chemical or solvent action, or both. stress-strain diagram—a diagram in which corresponding stripping—the removal of formwork or a mold. (See also values of stress and strain are plotted against each other; demold.) values of stress are usually plotted as ordinates (vertically) strips, divider—in terrazzo work, nonferrous metal or plas- and values of strain as abscissas (horizontally). tic strips of different thicknesses, usually embedded from stresses, initial—the stresses occurring in prestressed-con- 5/8 to 1-1/4 in. (10 to 40 mm), used to form panels in the crete members before any losses occur. topping. stressing end—in prestressed concrete, the end of the ten- strongback—a frame attached to the back of a form or pre- don at which the load is applied when tendons are cast structural member to stiffen or reinforce the form or stressed from one end only. member during concrete placing operations or handling stretcher—a masonry unit laid with its length horizontal operations. and parallel with the face of a wall or other masonry structural adhesive—a bonding agent used for transferring member. (See also header.) required loads between adherents exposed to service en- strike—see striking. vironments typical for the structure involved. strikeoff—to remove concrete in excess of that which is re- structural concrete—see concrete, structural. quired to fill the form evenly or bring the surface to structural end-point—the acceptance criterion of ASTM E grade; performed with a straightedged piece of wood or 119, which states that the specimen shall sustain the ap- metal by means of a forward sawing movement or by a plied load without collapse. power operated tool appropriate for this purpose; also the name applied to the tool. (See also screed and screed- structural lightweight concrete—see concrete, structural ing.) lightweight. striking—the releasing or lowering of centering or other structural sandwich construction—see construction, temporary support. structural sandwich. stringer—a secondary flexural member that is parallel to strut—see shore. the longitudinal axis of a bridge or other structure. (See stub wall—see wall, stub. also beam.) stucco—a cement plaster used for coating exterior walls and stringing mortar—see mortar, stringing. other exterior surfaces of buildings. (See also plaster.) strip—to remove formwork or a mold; also a long thin piece stud— of wood, metal, or other material. (See also demold and 1. member of appropriate size and spacing to support stripping.) sheathing of concrete forms; and strip, cant—see strip, chamfer (preferred term). 2. a headed steel device used to anchor steel plates or strip, chamfer—either a triangular or curved insert shapes to concrete members. placed in an inside form corner to produce either a subaqueous concrete—see concrete, underwater.

CEMENT AND CONCRETE TERMINOLOGY 116R-65 subbase subbase—a layer in a pavement system between the sub- surface texture—degree of roughness or irregularity of the grade and the base course, or between the subgrade and a exterior surfaces of aggregate particles and also of hard- portland-cement concrete pavement. ened concrete. subgrade—the soil prepared and compacted to support a surface vibrator—see vibrator, surface. structure or a pavement system. surface voids—see voids, surface. subgrade modulus—see coefficient of subgrade reaction. surface water—see moisture, surface (preferred term). subgrade reaction—see contact pressure and coefficient surfactant—a shortened form of the term “surface-active of subgrade reaction. agent.” subpurlin—a light structural section used as a secondary surkhi—a pozzolan consisting of burned clay powder prin- structural member; in lightweight concrete roof construc- cipally produced in India. tion, used to support the form boards over which the light- sustained modulus of elasticity—see modulus of elastici- weight concrete is placed. ty, sustained. subsample—a sample taken from another sample. sway brace—a diagonal brace used to resist wind or other   
 
 #   ( ) #     %   lateral forces. (See also bracing; cross bracing; and X- 6"" µ   brace.) substructure —all of that part of a structure below grade. swelling—increase in either length or volume. (See also sulfate attack—either a chemical reaction, physical reac- contraction; expansion; volume change; and volume tion, or both between sulfates usually in soil or ground change, autogenous.) water and concrete or mortar; the chemical reaction is pri- swift—a reel or turntable on which prestressing tendons are marily with calcium aluminate hydrates in the cement- placed to facilitate handling and placing. paste matrix, often causing deterioration. swirl finish—see finish, swirl. sulfate resistance—see resistance, sulfate. Swiss hammer—see hammer, rebound (preferred term). sulfate-resistant cement—see cement, sulfate-resistant. syneresis—the contraction of a gel, usually evidenced by the sulfoaluminate cement—see cement, expansive, Type K. separation from the gel of small amounts of liquid; a pro- superimposed load—see load, superimposed. cess possibly significant in the bleeding and cracking of superplasticizer—see admixture, water-reducing (high- fresh hydraulic-cement mixtures. range) (preferred term). syngenite—potassium calcium sulfate hydrate, a compound superstructure—all of that part of a structure above grade. sometimes produced during hydration of portland ce- supersulfated cement—see cement, supersulfated. ment, found in deteriorating portland-cement concrete surface— and said to form in portland cement during storage by re- surface, brushed—a sandy texture obtained by brushing action of potassium sulfate and gypsum. the surface of freshly placed or slightly hardened con- system— crete with a stiff brush for architectural effect or, in system, one-way—the arrangement of steel reinforce- pavements, to increase skid resistance. (See also fin- ment within a slab that presumably bends in only one ish, broom.) direction. surface, specific—the surface area of particles or of air system, two-way—a system of reinforcement; bars, rods, voids contained in a unit mass or unit volume of a ma- or wires placed at right angles to each other in a slab terial; in the case of air voids in hardened concrete, the and intended to resist stresses due to bending of the surface area of the air-void volume expressed as slab in two directions. square inches per cubic inch or square millimeters per Système International—see SI. cubic millimeter. systems building—see industrialized building. surface active—having the ability to modify surface energy and to facilitate wetting, penetrating, emulsifying, dispers- T ing, solubilizing, foaming, frothing, etc., of other substances. surface-active agent—agent, surface-active. T & G—see tongue and groove. surface air voids—small regular or irregular cavities, usual- table, flow—a flat, circular jigging device used in making ly not exceeding 15 mm in diameter, resulting from en- flow tests for consistency of cement paste, mortar, or con- trapment of air bubbles in the surface of formed concrete crete. (See also flow, [2]). during placement and consolidation. (See also sack rub.) talc—a mineral with a greasy or soapy feel, very soft, having surface area—see surface, specific. the composition Mg3Si4O10(OH)2. (See also cement, surface bonding (of masonry)—bonding of dry-laid mason- masonry and Mohs scale.) ry by parging with a thin layer of fiber-reinforced mortar. tamp process—see process, tamp. surface moisture—see moisture, surface. tamper— surface retarder—see retarder, surface. 1. an implement used to consolidate concrete or mortar in surface tension—an internal molecular force that exists in molds or forms; and the surface film of all liquids and tends to prevent the liq- 2. a hand-operated device for consolidating floor topping uid from flowing. or other unformed concrete by impact from the

116R-66 ACI COMMITTEE REPORT tetracalcium

dropped device in preparation for strikeoff and finish- tendons, deflected—tendons that have a trajectory that is ing; contact surface often consists of a screen or a grid curved or bent with respect to the gravity axis of the of bars to force coarse aggregates below the surface to concrete member. prevent interference with floating or troweling. (See tendons, draped—see tendons, deflected. also jitterbug.) tendons, harped—see tendons, deflected. tamping—the operation of consolidating freshly placed tendons, nonconcordant—in statically indeterminate concrete by repeated blows or penetrations with a tamper. structures, tendons, the center of gravity of which is (See also consolidation and rodding.) not coincident with the pressure line due to prestress- tamping rod—see rod, tamping. ing alone. (See also cap cables.) tangent modulus—see modulus of elasticity. tendon profile—the path or trajectory of the prestressing T-beam—a beam composed of a stem and a flange in the tendon. form of a T. tensile strength—see strength, tensile. telltale—any device designed to indicate movement of tensile strength, splitting—tensile strength of concrete de- formwork or of a point on the longitudinal surface of a termined by a splitting tensile test. pile under load. tensile stress—see stress. temperature— tension, diagonal—the principal tensile stress resulting temperature, glass-transition—the midpoint of the from the combination of normal and shear stresses acting temperature range over which an amorphous material upon a structural element. (such as glass or a high polymer) changes from (or to) tension reinforcement—see reinforcement, tension. a brittle, vitreous state to (or from) a plastic state. terrazzo concrete—see concrete, terrazzo. temperature, heat-deflection—the temperature at which tesserae—small pieces of glass or marble tile used in mosaics. a plastic material has an arbitrary deflection when sub- test—a trial, examination, observation, or evaluation used as jected to an arbitrary load and test condition; this is an a means of measuring either a physical or a chemical indication of the glass-transition temperature. characteristic of a material, or a physical characteristic of temperature, steel—see reinforcement, temperature. either a structural element or a structure. temperature cracking—see cracking, temperature. test, air-permeability—a procedure for measuring the temperature reinforcement—see reinforcement, tem- fineness of powdered materials such as portland cement. perature. test, Atterberg—a method for determining the plasticity temperature rise—the increase of temperature caused by of soils. either absorption of heat or internal generation of heat, for test, ball—a test to determine the consistency of freshly example, hydration of cement in concrete. mixed concrete by measuring the depth of penetration temperature-rise period—see period, temperature-rise. of a cylindrical metal weight with a hemispherical bot- temperature stress—see stress, temperature. tom. (See also kelly ball.) temper—to add water to concrete or mortar as necessary to test, Blaine—a method for determining the fineness of ce- bring the mixture initially to the desired workability (see ment or other fine material on the basis of the permeabil- also retempering.) ity to air of a sample prepared under specified conditions. template—a thin plate or board frame used as a guide in po- test, compression—test made on a test specimen of mor- sitioning or spacing form parts, reinforcement, or an- tar or concrete to detemrine the compressive strength; chors; also a full-size mold, pattern, or frame, shaped to in the U.S., unless otherwise specified, compression serve as a guide in forming or testing contour or shape. tests of mortars are made on 2 in. (50 mm) cubes and temporary stress—see stress, temporary. compression tests of concrete are made on cylinders 6 tendon—a steel element, such as wire, cable, bar, rod, in. (152 mm) in diameter and 12 in. (305 mm) high. strand, or a bundle of such elements, primarily used in test, hot-load—a test for determining the resistance to de- tension to impart compressive stress to concrete. formation or shear of a refractory material when sub- tendon, bonded—a prestressing tendon that is bonded to jected to a specified compressive load at a specified the concrete either directly or through grouting. temperature for a specified time. tendon, eccentric—a prestressing tendon that follows a test, Los Angeles abrasion—test for abrasion resistance trajectory not coincident with the gravity axis of the of concrete aggregates. concrete member. test, remolding—a test to measure remoldability. tendon, unbonded—a tendon that is permanently pre- test, slump—the procedure for measuring slump. vented from bonding to the concrete after stressing. testing machine—a device for applying test conditions and tendons, concentric— tendons following a line coinci- accurately measuring results. dent with the gravity axis of the prestressed-concrete tetracalcium aluminoferrite—a compound in the calcium member. aluminoferrite series, having the composition ⋅ ⋅ tendons, concordant—tendons, in statically indetermi- 4CaO Al2O3 Fe2O3, abbreviated C4AF, that is usually as- nate structures, that are coincident with the pressure sumed to be the aluminoferrite present when compound line produced by the tendons; such tendons do not pro- calculations are made from the results of chemical analysis duce secondary moments. of portland cement. (See also brownmillerite.)

CEMENT AND CONCRETE TERMINOLOGY 116R-67 texture texture—the pattern or configuration apparent in an exposed tilt-up—a construction technique for casting concrete ele- surface, as in concrete and mortar, including roughness, ments in a horizontal position at the jobsite and then tilt- streaking, striation, or departure from flatness. ing them to their final position in a structure. texturing—the process of producing a special texture on ei- time-dependent deformation—see deformation, time-de- ther unhardened or hardened concrete. pendent. T-head—in precast framing, a segment of girder crossing time, final setting—the time required for a freshly mixed the top of an interior column; also the top of a shore cement paste, mortar, or concrete to achieve final set. (See formed with a braced horizontal member projecting on also time, initial setting.) two sides forming a T-shaped assembly. time, initial setting—the time required for a freshly mixed thermal conductance—see conductance, thermal. cement paste, mortar, or concrete to achieve initial set. thermal conductivity—see conductivity, thermal. (See also time, final setting.) thermal contraction—contraction caused by decrease in time of haul—in production of ready-mixed concrete, the temperature. period from first contact between mixing water and ce- thermal diffusivity—see diffusivity, thermal. ment until completion of discharge of the freshly mixed thermal expansion—expansion caused by increase in tem- concrete. perature. time of set—see time of setting. thermal movement—change of dimension of concrete or time of setting — masonry resulting from change of temperatures. (See also 1. the time required for a freshly mixed cement paste, contraction and expansion.) mortar, or concrete to achieve initial set (see set, ini- thermal resistance—see resistance, thermal. tial) or; thermal shock—see shock, thermal. 2. the time required for a freshly mixed cement paste, thermal stress—see stress, temperature. mortar, or concrete to achieve final set (see set, final). tobermorite—a mineral found in Northern Ireland and else- thermal volume change—see volume change, thermal. where, having the approximate formula thermocouple—two conductors of different metals joined Ca Si O (OH) ⋅4H O, identified approximately with the together at both ends, producing a loop in which an elec- 5 6 16 2 2 artificial product tobermorite (G) of Brunauer, a hydrated tric current will flow when there is a difference in temper- calcium silicate having a CaO:SiO ratio in the range 1.39 ature between the two junctions. 2 to 1.75 and forming minute layered crystals that constitute thermoplastic—becoming soft when heated and hard when the principal cementing medium in portland-cement con- cooled. crete; a mineral with 5 mols of lime to 6 mols of silica, usu- thermosetting—becoming rigid by chemical reaction and ally occurring in plate-like crystals, which is easily not remeltable. synthesized at steam pressures of about 100 psi and higher; thin-shell precast—precast concrete characterized by thin the binder in several properly autoclaved products. slabs and web sections. (See also construction, shell.) tobermorite gel—see gel, tobermorite. thixotropy—the property of a material that enables it to toenail— stiffen in a short period while at rest, but to acquire a low- 1. an obliquely driven nail; and er viscosity when mechanically agitated, the process be- 2. to drive a nail at an angle. ing reversible; a material having this property is termed tolerance— thixotropic or shear thinning. (See also rheology.) 1. the permitted variation from a given dimension or threaded anchorage—see anchorage, threaded. quantity; tie— 2. the range of variation permitted in maintaining a spec- 1. loop of reinforcing bars encircling the longitudinal ified dimension; and steel in columns; and 3. a permitted variation from location or alignment. 2. a tensile unit adapted to holding concrete forms secure tom—see shore (preferred term). against the lateral pressure of unhardened concrete. tongue and groove—a joint in which a protruding rib on the tie, form—a mechanical connection in tension used to pre- edge of one side fits into a groove in the edge of the other vent concrete forms from spreading due to the fluid pres- side; abbreviated “T & G.” (See also keyway.) sure of fresh concrete. tool, arrissing—a tool similar to a float, but having a form tie bar—see bar, tie. suitable for rounding an edge of freshly placed concrete. tie bar, deformed—see bar, tie. tool, gutter—a tool used to give the desired shape and finish tie rod—see tie, form and tieback. to concrete gutters. tieback—a rod fastened to a deadman, a rigid foundation, or tooling—the act of compacting and contouring a material in either a rock or soil anchor to prevent lateral movement of a joint. formwork, sheet pile walls, retaining walls, bulkheads, etc. top form—see form, top. tied column—see column, tied. topping— tiers—see lifts (preferred term). 1. a layer of concrete or mortar placed to form a floor sur- tilting mixer—see mixer, tilting. face on a concrete base;

116R-68 ACI COMMITTEE REPORT two-stage

2. a structural, cast-in-place surface for precast floor and provide full, firm, and uniform support for the lower 210 roof systems; and degrees of the pipe. 3. the mixture of marble chips and matrix that, when trial batch—see batch, trial. properly processed, produces a terrazzo surface. triaxial compression test—a test in which a specimen is topping, dry—see dry-shake (preferred term). subjected to a confining hydrostatic pressure and then topping, monolithic—on flatwork, a higher quality, more loaded axially to failure. serviceable topping course placed promptly after the base triaxial test—a test in which a specimen is subjected simul- course has lost all slump and bleed water. taneously to lateral and axial loads. torque viscometer—see viscometer, torque. tricalcium aluminate—a compound having the composi- torsional stress—see stress, torsional. ⋅ tion 3CaO Al2O3, abbreviated C3A. toughness—the property of matter that resists fracture by tricalcium silicate—a compound having the composition impact or shock. ⋅ 3CaO SiO2, abbreviated C3S, an impure form of which tower—a composite structure of frames, braces, and acces- (alite) is a main constituent of portland cement. (See also sories. alite.) trajectory of prestressing force—see path of prestressing trough, flow—a sloping trough used to convey concrete by force. gravity flow from either a truck mixer or a receiving hop- transfer—the act of transferring the stress in prestressing per to the point of placement. (See also chute.) tendons from the jacks or pretensioning bed to the con- trough mixer—see mixer, open-top. crete member. trowel—a flat, broad-blade steel hand tool used in the final transfer bond—see bond, transfer. stages of finishing operations to impart a relatively transfer length—see length, transfer (preferred term). smooth surface to concrete floors and other unformed transfer strength—see strength, transfer. concrete surfaces; also a flat triangular-blade tool used for transformed section—see section, transformed. applying mortar to masonry. (See also fresno trowel.) transit-mixed concrete—see concrete, transit-mixed. trowel finish—see finish, trowel. transit-mixer—see mixer, truck. troweling—smoothing and compacting the unformed sur- translucent concrete—see concrete, translucent. face of fresh concrete by strokes of a trowel. transmission length—see length, transfer. troweling machine—a motor driven device that operates or- transverse cracks—see cracks, transverse. biting steel trowels on radial arms from a vertical shaft. transverse joint—see joint, transverse. truck, agitating—a vehicle in which freshly mixed concrete transverse prestress—see prestress, transverse. can be conveyed from the site of mixing to the site of transverse reinforcement—see reinforcement, trans- placement; while being agitated, the truck body can either verse. be stationary and contain an agitator, or it can be a drum transverse strength—see strength, flexural and modulus rotated continuously so as to agitate the contents; desig- of rupture. nated “agitating lorry” in the UK. traprock—any of various fine-grained, dense, dark colored truck-mixed concrete—see concrete, transit-mixed. igneous rocks, typically basalt or diabase; also called q- truck mixer—see mixer, truck. “trap.” T-shore—a shore with a T-head. trass—a natural pozzolan of volcanic origin found in Ger- tub mixer—see mixer, open-top (preferred term). many, namely, trachytic tuffs that are intensely altered by geologic processes. tube-and-coupler shoring—a load-carrying assembly of traveler—an inverted-U-shaped structure usually mounted tubing or pipe which serves as posts, braces, ties, a base on tracks that permit it to move from one location to an- supporting the posts, and special couplers that connect the other to facilitate the construction of an arch, bridge, or uprights and join the various members. building. tunnel lining—a structural system of concrete, steel, or other travertine—dense to irregularly porous, commonly strati- materials to provide support for a tunnel for exterior loads, fied or banded calcium carbonate, either aragonite or cal- to reduce water seepage, or to increase flow capacity. cite, formed by deposition from hot spring waters. turbidimeter—a device for measuring the particle-size dis- tremie—a pipe or tube through which concrete is deposited tribution of a finely divided material by taking successive under water, having at its upper end a hopper for filling measurements of the turbidity of a suspension in a fluid. and a bail for moving the assemblage. turbidimeter fineness—the fineness of a material such as tremie seal—the depth to which the discharge end of the portland cement, usually expressed as total surface area in tremie pipe is kept embedded in the fresh concrete that is square centimeters per gram, as determined with a turbi- being placed; a layer of tremie concrete placed in a cof- dimeter. (See also Wagner fineness.) ferdam for the purpose of preventing the intrusion of wa- turbine mixer—see mixer, open-top (preferred term). ter when the cofferdam is dewatered. twin-twisted bar reinforcement—see reinforcement, trench form (for cast-in-place concrete pipe)—the verti- twin-twisted bar. cal sides and semicircular bottom of the trench shaped to two-stage curing—see curing, two-stage.

CEMENT AND CONCRETE TERMINOLOGY 116R-69 two-way two-way reinforced footing—a footing having reinforce- unit water content—the quantity of water per unit volume of ment in two directions generally perpendicular to each freshly mixed concrete, often expressed as lb or gal./yd3; other. the quantity of water on which the water-cement ratio is two-way reinforcement—see reinforcement, two-way. based, not including water absorbed by the aggregate. two-way system—see system, two-way. unit weight—deprecated term; see density. Type I cement—see cement, normal (preferred term). unit weight, fired—see density, fired. Type II cement—see cement, modified (preferred term). unsound—not firmly made, placed, or fixed; subject to de- Type III cement—see cement, high-early strength (pre- terioration or disintegration during service exposure. ferred term). Type IV cement—see cement, low-heat (preferred term). V Type V cement—see cement, sulfate-resistant (preferred term). vacuum concrete—see concrete, vacuum. vacuum dewatering—see concrete, vacuum. vacuum saturation—see saturation, vacuum. U valve bag—paper bag for cement or other material, either U-value—overall coefficient of heat transmission; a stan- glued or sewn, made of four or five plies of kraft paper and dard measure of the rate at which heat will flow through a completely closed except for a self-sealing paper valve unit area of a material of known thickness. through which the contents are introduced and released. ultimate-design resisting moment—the moment at which a vapor barrier—see barrier, vapor. reinforced-concrete section reaches its usable flexural vapor pressure—a component of atmospheric pressure; strength, commonly accepted for under-reinforced con- caused by the presence of vapor; expressed in inches, cen- crete flexural members to be the bending moment at timeters, or millimeters of height of a column of mercury; which the concrete compressive strain equals 0.003; an or, in SI, in pascals. obsolete term. variation—see coefficient of variation and standard de- ultimate load—see load, ultimate. viation. vebe apparatus—an apparatus for measuring workability of ultimate moment—an obsolete term; see strength, nomi- very low-slump or no-slump concrete, including a vibrat- nal flexural. ing table, a sample container, and other ancillary items, ultimate shear strength—an obsolete term; see strength, that permits measurement of the time (vebetime) required nominal shear. to be consolidated in a mold. ultimate strength—an obsolete term; see strength, nominal. vehicle—liquid carrier or binder of solids. ultimate-strength design—see strength-design method. velocity, pulse—the velocity at which compressional waves ultrasonic—pertaining to mechanical vibrations having a are propagated through a medium. frequency greater than approximately 20,000 Hz. velocity, settling— the terminal rate of fall of a particle unbonded member—a prestressed concrete member post- through a fluid as induced by gravity or other external tensioned with tendons that are not bonded to the concrete force; the rate at which frictional drag balances the accel- between the end anchorages after stressing. erating force (or the external force). unbonded post-tensioning—post-tensioning in which the veneer—a masonry facing that is attached to the backup, but tendons are not grouted after stressing. not so bonded as to act with it under load. unbonded tendon—see tendon, unbonded. Venetian—a type of terrazzo topping that incorporates large unbraced length of column—distance between lateral chips of stone. supports. vent pipe—see pipe, vent. underbed—the base mortar, usually horizontal, into which vented form—see form, vented. strips are embedded and on which terrazzo topping is vermiculite—a micaceous mineral; also a group name for applied. certain platy minerals, hydrous silicates of aluminum, undersanded—concrete containing an insufficient propor- magnesium, and iron, characterized by marked exfolia- tion of fine aggregate to produce optimum properties in tion on heating; also a constituent of clays. the fresh mixture, especially workability and finishing vermiculite concrete—see concrete, vermiculite. characteristics. vertical-shaft mixer—see mixer, vertical-shaft. undersize—particles of aggregate passing a designated vibrated concrete—see concrete, vibrated. sieve. vibration—energetic agitation of freshly mixed concrete underwater concrete—see concrete, underwater. during placement by mechanical devices, either pneumat- unhardened concrete—see concrete, fresh (preferred ic or electric, that create vibratory impulses of moderately term). high frequency to assist in consolidating the concrete in unreinforced concrete—see concrete, plain. the form or mold. unit masonry—see masonry, unit. 1. external vibration employs vibrating devices attached unit strain—see strain, unit. at strategic positions on the forms and is particularly

116R-70 ACI COMMITTEE REPORT water

applicable to manufacture of precast items and for vi- able and impermeable voids, but excluding space be- bration of tunnel-lining forms; in manufacture of con- tween particles; in the case of fluids, their volume. crete products, external vibration or impact may be volume, dry-rodded—the bulk volume occupied by a dry applied to a casting table; aggregate compacted by rodding under standardized 2. internal vibration employs one or more vibrating ele- conditions; used in measuring density of aggregate. ments that can be inserted into the fresh concrete at se- volume batching—measuring the constituents of mortar lected locations, and is more generally applicable to or concrete by volume. in-place construction; and volume change—an increase or decrease in volume due to 3. surface vibration employs a portable horizontal plat- any cause. (See also deformation and deformation, form on which a vibrating element is mounted. time-dependent.) vibration limit—see limit, vibration. volume change, autogenous—change in volume pro- vibrator—an oscillating machine used to agitate fresh con- duced by continued hydration of cement, exclusive of crete so as to eliminate gross voids, including entrapped effects of applied load and change in either thermal air but not entrained air, and to produce intimate contact condition or moisture content. with form surfaces and embedded materials. (See also vi- volume change, thermal—the increase or decrease in bration.) volume caused by changes in temperature. (See ther- vibrator, external—see vibrator. mal contraction and thermal expansion.) vibrator, spud—a vibrator, having a vibrating casing or a vibrating head, used to consolidate freshly placed con- W crete by insertion into the mass. waffle—see dome. vibrator, surface—a vibrator used for consolidating con- Wagner fineness—the fineness of portland cement, ex- crete by application to the surface of a mass of freshly pressed as total surface area in square centimeters per mixed concrete; four principal types exist: vibrating gram, determined by the Wagner turbidimeter apparatus screeds, pan vibrators, plate or grid vibratory tampers, and procedure. and vibratory roller screeds. wale—a long formwork member (usually double) used to Vicat apparatus—a penetration device used in the testing gather loads from several studs (or similar members) to of hydraulic cements and similar materials. allow wider spacing of the restraining ties; when used Vicat needle—see needle, Vicat. with prefabricated panel forms, this member is used to viscometer—instrument for determining viscosity of slur- maintain alignment; also called waler or ranger. ries, mortars, or concretes. waler—see wale. viscometer, torque—an apparatus used for measuring the wall—a vertical element used primarily to enclose or sepa- consistency of slurries in which the energy required to ro- rate spaces. tate a device suspended in a rotating cup is proportional wall, enclosure—a non-load-bearing wall intended only to viscosity. to enclose space. viscosity—the property of a material that resists change in wall, load-bearing—a wall designed and built to carry the shape or arrangement of its elements during flow, and superimposed vertical or in-plane and shear loads, or the measure thereof. both. (See also wall, nonbearing.) visual concrete—see concrete, architectural and con- wall, nonbearing—a wall that supports no vertical load crete, exposed. other than its own weight and no in-plane shear loads. void— (See also load-bearing wall.)  

 # #  # # wall, stub—low wall, usually 4 to 8 in. (100 to 200 mm) ( )   !     # #  & high, placed monolithically with a concrete floor or #*  >  %  ! other members to provide for control and attachment       #$) * µ * of wall forms; called kicker in the UK.       #   wall form—see form, wall. void, water—void along the underside of an aggregate warehouse pack—see set, warehouse and cement, sticky. particle or reinforcing steel which formed during the warehouse set—see set, warehouse. bleeding period; initially filled with bleed water. warping—a deviation of a slab or wall surface from its orig- void-cement ratio—volumetric ratio of air plus net mixing inal shape, usually caused by either temperature or mois- water to cement in a concrete or mortar mixture. ture differentials or both within the slab or wall. (See also voids, surface—cavities visible on the surface of a solid. curling.) (See also bug holes.) warping joint—see joint, warping. volatile material—material that is subject to release as a gas wash (or flush) water—see water, wash (or flush). or vapor; liquid that evaporates readily. water— volume— water, absorbed—see moisture, absorbed. volume, absolute—in the case of solids, the displacement water, adsorbed—water held on surfaces of a material volume of particles themselves, including their perme- by electrochemical forces and having physical proper-

CEMENT AND CONCRETE TERMINOLOGY 116R-71 water

ties substantially different from those of absorbed wa- watertight—impermeable to water except when under hy- ter or chemically combined water at the same drostatic pressure sufficient to produce structural discon- temperature and pressure. (See also adsorption.) tinuity by rupture. water, evaporable—water in set cement paste present in water void—see void, water. capillaries or held by surface forces; measured as that w/c—see water-cement ratio. removable by drying under specified conditions. (See w/cm—see water-cementitious material ratio. also water, nonevaporable.) weakened-plane joint—see joint, groove and joint, con- water, flush—see water, wash (or flush). traction (preferred term). water, free—see moisture, free. wearing course—a topping or surface treatment to increase water, gage—see batched water. the resistance of a concrete pavement or slab to abrasion. water, mixing—the water in freshly mixed sand-cement weathering—changes in color, texture, strength, chemical grout, mortar, or concrete, exclusive of any previously composition or other properties of a natural or artificial absorbed by the aggregate (for example, water consid- material due to the action of the weather. ered in the computation of the net water-cement ratio). web bar—see reinforcement, web (preferred term). (See also batched water and moisture, surface.) web reinforcement—see reinforcement, web. water, nonevaporable—the water that is chemically wedge—a piece of wood or metal tapering to a thin edge; combined during cement hydration; not removable by used to adjust elevation or tighten formwork. specified drying. (See also water, evaporable.) wedge anchorage—see anchorage, wedge. water, wash (or flush)—water carried on a truck mixer in weigh batching—measuring the constituent materials for a special tank for flushing the interior of the mixer after mortar or concrete by mass. discharge of the concrete. weight, dry-batch—the mass of the materials, excluding water blast—a system of cutting or abrading a surface such water, used to make a batch of concrete. as concrete by a stream of water ejected from a nozzle at weight, dry-rodded—deprecated term; see density, dry- high velocity. rodded. water-cement ratio—the ratio of the mass of water, exclu- welded-butt splice—see splice, welded-butt. sive only of that absorbed by the aggregates, to the mass welded reinforcement—see reinforcement, welded. of portland cement in concrete, mortar, or grout, stated as welded-wire fabric—see fabric, welded-wire. a decimal and abbreviated as w/c. (See also water-cemen- welded-wire fabric reinforcement—see reinforcement, titious material ratio.) welded-wire fabric. water-cementitious material ratio—the ratio of the mass well-graded aggregate—see aggregate, well-graded. of water, exclusive only of that absorbed by the aggre- wet—covered with visible free moisture; not dry. (See also gate, to the mass of cementitious material (hydraulic) in damp and moist.) concrete, mortar, or grout, stated as a decimal and abbre- wet-cast process—see process, wet-cast. viated as w/cm. (See also water-cement ratio.) wet process—see process, wet. water gain—see bleeding. wet screening—screening to remove fresh concrete aggre- water pocket—see void, water. gate particles larger than a certain size. waterproof—impervious to water in either liquid or vapor wet-mix shotcrete—see shotcrete, wet-mix. state. (See also dampproof.) (Note: Because nothing can wet sieving—use of water to ficilitate sieving of a granular be completely impervious to water under infinite pressure material on standard sieves. over infinite time, this term should not be used.) wettest stable consistency—see consistency, wettest stable. waterproofed cement—see water repellent. wetting agent—see agent, wetting. waterproofing—see dampproofing (preferred term). wheel, feed—material distributor or regulator in certain waterproofing compound—see compound, waterproofing. types of shotcrete equipment. water-reducing admixture—see admixture, water-re- wheel load—see load, wheel. ducing. white cement—see cement, white. water-reducing admixture (high-range)—see admixture, width, effective flange—width of slab adjoining a beam water-reducing (high-range). stem where the slab is assumed to function as the flange water-repellent—property of a surface that resists wetting element of a T-beam section. (by matter in either liquid or vapor state) but permits pas- wing pile—see pile, wing. sage of water when hydrostatic pressure occurs. (See also wire— watertight.) wire, alignment—see wire, ground. water-resistant—see water-repellent (preferred term). wire, cold-drawn—wire made from rods that are hot- water ring—a device in the nozzle body of dry-mix shotcrete rolled from billets and then cold-drawn through dies. equipment through which water is added to the materials. (See also reinforcement, cold-drawn wire.) waterstop—a thin sheet of metal, rubber, plastic, or other wire, crimped—wire deformed into a curve that approx- material inserted across a joint to obstruct the seepage of imates a sine curve as a means of increasing the capac- water through the joint. ity of the wire to bond to concrete; also welded wire

116R-72 ACI COMMITTEE REPORT zone

fabric crimped to provide an integral chair. (See also (150 to 350 C) under saturated steam pressure; a constitu- reinforcement, deformed and wire, indented.) ent of sand-lime masonry units. wire, ground—small-gage high-strength steel wire used X-ray diffraction—the diffraction of X-rays by substances to establish line and grade as in shotcrete work; also having a regular arrangement of atoms; a phenomenon called alignment wire and screed wire. used to identify substances having such structure. wire, indented—wire having machine-made surface in- X-ray emission spectroscopy—see X-ray fluorescence. dentations intended to improve bond; depending on X-ray fluorescence—characteristic secondary radiation the type of wire, used for either concrete reinforce- emitted by an element as a result of excitation by X-rays, ment or pretensioning tendons. used to yield chemical analysis of a sample. wire mesh—see fabric, welded-wire. wire wrapping—application of high tensile wire, wound Y under tension by machines, around circular concrete or yellowing—development of yellow color or cast in white or shotcrete walls, domes, or other tension-resisting struc- clear coatings as a consequence of aging. tural components. yield—the volume of freshly mixed concrete produced from wobble coefficient—a coefficient used in determining the a known quantity of ingredients; the total mass of ingre- friction loss occurring in post-tensioning, which is assumed dients divided by the density mass of the freshly mixed to account for the secondary curvature of the tendons. concrete; also the number of units produced per bag of ce- wobble friction—see friction, wobble. ment or per batch of concrete. wood block—see block, wood. yield point—the first engineering stress in a test in which workability—that property of freshly mixed concrete or stresses and strains are determined for a material that ex- mortar that determines the ease with which it can be hibits the phenomenon of discontinuous yielding, of which mixed, placed, consolidated, and finished to a homoge- an increase in strain occurs without an increase in stress. nous condition. yield strength—see strength, yield. working load—see load, working. yoke—a tie or clamping device around column forms or over working stress—see stress, working. the top of wall or footing forms to keep them from spreading working-stress design—see design, working-stress. because of the lateral pressure of fresh concrete; also part of woven-wire fabric—see fabric, woven-wire. a structural assembly for slipforming which keeps the forms woven-wire reinforcement—see fabric, welded-wire (pre- from spreading and transfers form loads to the jacks. ferred term). Young’s modulus—see modulus of elasticity (preferred term). wrapping—see strand wrapping and wire wrapping. wrecking strip—see strip, wrecking. Z wythe (leaf)—each continuous vertical section of a wall that is one masonry unit or grouted space in thickness. zero-slump concrete—see concrete, zero slump. zone, anchorage—in post-tensioning, the region adjacent to X the anchorage subjected to secondary stresses resulting from the distribution of the prestressing force; in preten- X-brace—paired set of crossing sway braces. (See also sioning, the region in which the transfer bond stresses are brace, cross bracing, and sway brace.) developed. xonotlite—calcium silicate monohydrate (Ca6Si6O17(OH)2), zone, precompressed—the area of a flexural member that is a natural mineral that is readily synthesized at 302 to 662 F compressed by the prestressing tendons.

CEMENT AND CONCRETE TERMINOLOGY 116R-73