ReportNo. FIIWA/RD-81/I53 CUMR-T-81-007 C3 , !LOANCOPY ONLY
TREMIECONCRETE FOR BRIDGE PIERS AND OTHERMASSIVE UNDERWATER PLACEMENTS
Washington, D.C, 20590
Documentis availableto the publicthrough *4' SeaGrant CollegeProgram the NationalTechnical Information Service, University of California Springfield, Virginia 221 61 U voila, CA 92093 FOREWORD
This report describes a laboratory and field investigation of concrete that is placed underwater by tremie. It will be of interest to bridge engineers and to other engineers concerned with hydraulic structures placed in rivers and along the coast. Technically, it presents recommended guidelines and specifi- cations to cover all aspects of a field construction project, such as mixture design, placement procedures, flow patterns, and temperature development.
The report presents the results of the study partially funded by the Federal Highway Administration, Office of Research, Washing- ton, D.C., under Contract DOT-FH-11-9402. This final report covers the entire study, which was initially sponsored and funded by NOAA, National Sea Grant College Program, Department of Commerce, under a grant to the California Sea Grant College Program, f04-7-158-44121, and by the California State Resource Agency, Project Number R/E-14. Sufficient copies of the report are being distributed to provide a minumum of one copy to each FHWA regional office, one copy to each FHWA division office, and one copy to each State highway agency. Direct distribution is being made to the division offices. Additional copies of the report for the public are available from the National Technical Information Service ANTIS!, Department of Commerce, 5285 Port Royal Road, Springfield, Virginia 22161.
Charles F. Sc ey Director, Office of Research Federal Highway Administration
NOT ICE
This document is disseminated under the sponsorship of the Department of Transportation in the interest of information exchange. The United States Government assumes no liability for its contents or use thereof. The contents of this report reflect the views of the contractor, who is responsible for the accuracy of the data presented herein. The contents do not necessarily reflect the official policy t>f the Department of Transportation. This report does not constitute a standard, specification, or regulation.
The United States Government does not endorse products or manufacturers. Trade or manufacturers' names appear herein only because they are considered essential to the object of this document. Technical ReportOoctteentotion Page
2. Government Accession Ho. 3. Recipient's Carolog Ho. 1. Report Ho.
FHWA/RD-81/153 S, Report Date d. Tiri ~ and Subtitlo September 1981 TREMIECONCRETE FORBRIDGE PIERS AND OTHER MASSIVE d. Per OneingOrgOnieatiOn Cede UNDERWATERPLACEMENTS fi. PerformingOrgonisotion Repor ~ Ho. Ben C. Gerwick, Jr., Terence C. Holland, and T-CSGCP-004 G. Juri. Komendant 10. Work Unit Ho. T R AlS! 9. PerformingOrganisation Home and Address FCP 34HO-004 Department of Civil Engineering ll. Controctar Grant Ho. University of California DOT-FH-11-9402 Berkeley, Calif. 94720 13. Typeof Reportand P ~ riodCovered SponsoringAgency Home ond Address Offices of Research and Development Final Re ort Federal Highway Administration SponsoringAgency Cods U~ S. Department of Transportation N/0720 Washington, D. C. 20590 SupplementaryHotes
FHWAcontract manaer: T. J. Pasko HRS-22 lb."h'"o" Thisstudy reviewed the placement of mass concrete under water using a tremie.Areas investigated included a! Mixturedesign of tremieconcrete including theuse of pozzolanicreplacement of portions of thecement; b! Flowpatterns and flowrelated characteristics of tremie-placedconcrete; c! Heatdevelopment andasso- ciatedcracking problems for tremieconcrete; d! Predictionof temperaturesin mas- sivetremie concrete placements; and e! Qualityof tremie-placedconcrete. Addi- tionally,the tremie placement of a massivecofferdam seal for a pierof a ma]or bridgeand the tremie placement of a deepcutoff wall through anexisting earthfill dam areA recommended examined. practice and a guidespecification for massivetremie placements areprovided. These items cover basic principles of tremieplacement, concrete mate- rials andmixture design, temperature considerations, placement equipment, preplace- mentplanning, placement procedures, and postplacement evaluation.
Item This 812 continued!work is a result of researchsponsored, in part, by NOAA,National Sea GrantCollege Program, Department of Commerce; under a grantto theCalifornia Sea GrantCollege Program,-404-7-158-44121, and.by the California State Resources Agency, Project NumberR/E 14.
16. Distrihunon Statement 17. Key Words No restrictions. This document is avail tremie concrete; portland cement; able to the public through the National underwater concrete; pozzolans; Technical Information Service, Spring- heat development in concrete; bridge pier construction,' field, Virginia 22161. concrete mixture design. 21~ Ho. of Pegrs 22. Price 19. SecurityClossif. of thisreport! 20. SecurityClassif. ef this poge! 203 Unclassified Unclassified
fore DOT F 1100.1 ~Pa e INTRODUCTION...... ~ 1 CHAPTER1. SMALL-SCALELABORATORY COMPARISONS OF SELECTED TREMIE CONCRETE MIXTURES. 1.1 Objectives. 1.2 Background. 3 3 1.2.1 Workability of tremie concrete. 3 1.2.2 Description of tests performed. ' ~ ~ ~ 1.2.3 Description of concrete mixtures evaluated. 4 6 1 ~ 3 Observations and discussion 12 1.3.1 Slump, unit weight, air content, and temperature tests 12 1.3.2 Tremie flow test. 15 1.3.3 Time of setting test. 15 1.3.4 Bleeding test 15 1.3.5 Segregation susceptibility tests. 15 1.3.6 Temperature development test. 15 1.3.7 Compressive strength test 19 1.3.8 Splitting tensile strength test 19 1.3.9 Slump loss test 19 1.3.10 Overall performance 19 1.4 Summary I t i ~ ~ ~ ~ ~ i ~ ~ ~ o ~ ~ 22 CHAPTER 2. LARGE-SCALE LABORATORYTESTS OF TREMIE CONCRETE PLACEMENT 2.1 Obj ective 23 2.2 Background. 23 2.2.1 Description of the test procedure 23 2.2.2 Description of concrete mixtures evaluated. 23 2.2.3 Flow of tremie concrete 30 2.3 Observations and discussion 30 2.3.1 Direct observations of concrete flow. 30 2.3.2 Flow during placement as determined by soundings 32 2.3.3 Surface profiles and surface appearance 37 2.3.4 Distribution of concrete colors 37 2.3.5 Concrete density. 55 2 ~ 3.6 Flow around reinforcing steel 57 2.3.7 Laitance formation. ~ ~ ~ 0 4 ~ i ~ ~ 57 2. 4 Summary I 61 CHAPTER3. TREMIECONCRETE PLACEMENT, I-205 COLUMBIA RIVER BRIDGE. 62 3 ~ 1 Objective 62 3.2 Background. 3.2.1 Description of the bridge 62 62 3.2.2 Geometry of Pier 12 62 3.2.3 Temperature predictions 62 3.2.4 Tremie concrete mixture 63 3.2.5 Placement technique 63 TABLE OF CONTENTS,Continued ~Pa e 3.3 Observations and discussion . 63 3.3.1 Measured temperatures 63 3.3.2 Measured versus predicted temperatures. 76 3.3.3 Concrete flow patterns, 79 3.3.4 Concrete quality. 82 82 3.4 Summa ry ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ r ~ CHAPTER 4 ~ TREMIE CONCRETECUTOFF WALLr WOLF CREEK DAM 87 87 4.1 Objective I e ~ t ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 87 4.2 Background. 4.2.1 Description of the dam. 87 4.2.2 Description of problem. 87 4.2.3 Repair procedures 87 4.3 Observations and discussion . 90 4.3.1 Quality of tremie concrete. 90 4.3.2 Tremie starting leakage 90 4.3.3 Tremie joint leakage. 93 4.3.4 Tremie centering. 93 4.3.5 Concrete placement rate 93 4.3.6 Tremie removal rate 93 4.3.7 Breaks in placing 96 4.3.8 Water temperature during placement. 96 4.3.9 Concrete mixture. 96 4.3.10 Observation of placements 96 4.3.11 Core and placement logs 96 4.3.12 Tremie resistance to flow 96 4.3.13 Potential for concrete segregation. 103 103 4.4 S ummary CHAPTER5. TEMPERATUREPREDICTIONS FOR TREMIE CONCRETE. 106 106 5.1 Objective 106 5.2 Background. 5.2.1 Need for finite element analysis 106 5.2.2 Finite element program selected 106 5.2.3 Cracking predictions. 106 106 5.3 Observations and discussion 5.3.1 General description Program TEMP 106 5.3.2 User options and variables. ~ ~ 106 5.3.3 Example of Progra~ TEMP usage 108 ill 5.4 Summary CHAPTER6. FLOWPREDICTIONS FOR TREM!E CONCRETE 117 117 6.1 Ob j ective 117 6.2 Background. 6.2.1 Literature review . ~ 117 6.2.2 Dutch investigation 118 118 6.3 Observations and discussion 6.3.1 Square placement model. 118 6.3.2 Advancing slope placement model ~ t ~ ~ ~ 120 6.3.3' Summaryof Dutch placement models 122 6.3.4 Dutch hydrostatic balance model 122 6.3.5 Example placement calculations. 122 122 6.4 S ummary TABLE OF CONTENTS,Concluded ~Pe CHAPTER7. CONCLUSXONSANDRECOMMENDATIONS. . . . , . . . i , ~ . . . . 127 7.1 Specific conclusions. 7.2 General conclusions 127 7.3 Recommendedpractice. 129 7. 4 Guide specif ica t ion ~ 130 7.5 Recommendations for further ~ l34 works o i ~ ~ ~ ~ 137 REFERENCES,~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ I ~ 139 APPENDIX A: CONCRETEMIXTURE PROPORTIONS MIXTUREEVALUATZON TESTS. . . , , ...... , . . . 141 B'. CONCRETEMATERIALS - MIXTURE EVALUATION TESTS . . . , . . . 143 C: SUMMARIZEDDATA - MIXTUREEVALUATION TESTS. 144 D: DETAXLEDDATA " MIXTURE EVALUATION TESTS, ...... ~ . . 146 E: SOUNDZNGDATA- LABORATORY PLACEMENT TESTS...... , ~ 149 F: SURFACEPROFILE DATA LABORATORY PLACEMENT TESTS. ~ . . . 151 Gl COLORLAYER DATA - LABORATORY PLACEMENT TESTS...... 153 He TEMPERATUREINSTRUMENTATION PLAN PIER 12! I 205 BRXDGE~ ~ ~ s ~ ~ ~ ~ ~ ~ ~ e ~ ~ ~ ~ s ~ ~ ~ a 1 55 I ~ DATARECORDING AND REDUCTION - TEMPERATURES ZN PIER12 SEALCONCRETE . . . . , . . o . ~ . ~ . . . . . , ~ 165 J ~ PREDICTEDVERSUS MEASURED TEMPERATURES - PZER12, I-205 BRIDGE. ~ ~ ~ 167 Kl LISTINGOF PROGRAM TEMP...... o . ~ 172 Ll USERINSTRUCTIONS - PROGRAM TEMP ~ 182 M: INTERFACEINSTRUCTIONS - PROGRAMS TEMPAND DETECT . . . . . 187 Nl SAMPLEOUTPUT - PROGRAMSTEMP AND DETECT. ~ ~ I 189 LIST OF ILJUSIRATEONS Fi ure No. Title ~Pa e Schematic of compacting factor apparatus Schematic of segregation susceptibility apparatus. Concrete sample after performance of segregation susceptibility test. Schematic of tremie flow test apparatus. Tremie flow test apparatus Tremie flow test being performed 10 Schematic of flow trough apparatus Partially assembled tremie placement box . . . ~ 24 Tremie placement box completely assembled and ready for placement. 10 Details of tremie hopper and pipe during a placement Schematic of tremie placement box. 12 Overall view of placement operation. 27 Taking sounding during break in. concrete placement 28 14 Coring pattern for large-scale laboratory placements 15 Tremie-placed concrete at completion of coring program 16 Observed and postulated flow of concrete near tremie pipe. 33 17 Sounding locations in tremie placement box 18 Tremie concrete profiles during placement, Test l. 34 19 Tremie concrete profiles during placement, Test 2. 35 20 Tremie concrete profiles during placement, Test 3. 21 Tremie concrete profiles during placement, Test 4. 36 22 Tremie concrete profiles during placement, Test 5. 36 23 Centerline and right edge surface profiles, Test 1 38 Centerline and right edge surface profiles, Test 2 38 25 Centerline and right edge surface profiles, Test 3 39 26 Centerline and right edge surface profiles, Test 4 39 27 Centerline and right edge surface profiles, Test 5 40 28 Concrete surface, Test 1 41 29 Close-up of concrete surface, Test 1 4 ~ ~ 41 30 Concrete surface, Test 2 42 31 Concrete surface, Test 3 LIST OF ILLUSTRATIONS, Continued Fi ure No. Title ~Pa e 32 Concrete surface, Test 4 43 33 Concrete surface, Test 5 44 34 Color distribution, Test 1 35 Color distribution, Test 2 45 36 Color distribution, Test 3 46 37 Color distribution, Test 4 46 38 Color distribution, Test 5 39 Cross section, Test 2. 48 40 Cross section, Test 2. 49 41 Cross section, Test 3. 50 42 Cross section, Test 3. 51 43 Cross section, Test 4. 52 44 Cross section, Test 4. 53 45 Cross section, Test 4. 54 Reinforcing steel placement. 47 Concrete laitance! flow around reinforcing steel, T es't 1 e ~ ~ ~ ~ ~ ~ ~ s ~ + ~ ~ i ~ ~ ~ ~ ~ ~ 59 48 Concrete flow around reinforcing steel, Test 5 60 49 Overall view of site during placement of tremie concrete for Pier 12 of I-205 Bridge 64 50 View inside cofferdam during tremie concrete placement. 51 Details of tremie placement equipment. 66 52 Tremie system being moved to new location. 67 53 Steel end plate and rubber washer being tied to end tremie pipe. 68 General instrumentation plan, Pier 12, I-205 Bridge. 69 Manual recording of temperatures in seal concrete. 70 56 Location of selected temperature instruments 73 57 Temperature history, instrument No. 8 ~ ~ ~ 74 58 Temperature history, instrument No. 11 74 59 Tempera ture history, instrument No. 24 75 60 Temperature history, instrument No. 29 75 61 Tremie concrete profiles at various times, long axis of seal 80 V1 LIST OF ILLUSTRATIONS, Continued ~Pa e Fi ure No. Title 62 Tremie concrete profiles at various times, long axis of seal 4 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 80 63 Tremie concrete profiles at various times, short axis of seal 64 Tremie concrete profiles at various times, short 81 axis of seal 83 65 Mounding on surface of seal. 83 66 Low area in surface of seal. 84 67 Core locations, Pier 12. 85 68 Section of core taken from tremie concrete 85 69 Water flowing from core hole in tremie seal. 88 70 Schematic of tremie-placed cutoff wall 89 71 Casing handling machine. 89 72 Breather tube in tremie hopper 91 73 Tremie support scheme. . . . . , . . . . . ~ 92 74 Secondary element excavation device. Cores taken from primary element 92 94 76 Pine sphere inside tremie at beginning of placement. 94 77 Position of pine sphere upon leaving tremie, 78 Fins added to tremie pipe to insure proper centering 97 79 Primary element at completion of tremie placement. 98 80 Key for Figures 81 through 84. 81 Analysis of element P-611. 100 82 Analysis of element P-985. 101 83 Analysis of element P-1001 102 84 Analysis of element S-576. ~ ~ ~ ~ ~ 104 85 Tremie geometry and derivation of resistance to flow 107 86 Geometry used by program TEMP. 109 87 Typical finite-element grids generated by program TEMP 112 88 Predicted versus measured temperatures, centerline 112 89 Predicted versus measured temperatures, outside edge 113 90 Predicted versus measured temperatures, off centerline 113 91 Predicted versus measured temperatures, outside edge 114 92 Section through seal showing locations of nodes. V11 LIST OP ILLUSTRATIONS, Concluded Title ~Pa e 93 Horizontal variation in predicted temperatures ...... 115 Vertical variation in predicted temperatures ...... 115 95 Section through seal showinghorizontal temperature gradientsi ~ ~ ~ I ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 116 96 Section through seal showing vertical temperature gradients. 116 97 Dutch failure model. 119 98 Dutch square placement model 119 99 Placementcurves derived from Dutch square placement model. 121 100 Dutch advancing slope placement model. 121 101 Geometry and notation for example spacing calculations 102 Geometry and notation of advancing slope technique 124 LIST OF TABLES Table No. Ti. tie ~Pa e Summary of test program 5 Summary of concrete mixtures tested 13 Summary of mixture evaluation test data 14 Rankings, tremie flow tests 16 Rankings, time of setting tests 16 Rankings, bleeding tests 17 Rankings, segregation susceptibility tests. 17 Rankings, temperature development tests 18 Rankings, compressive strength tests. 18 10 Rankings, splitting tensile strength tests. 20 Rankings, slump loss tests. 20 12 Overall concrete performance. 21 13 Characteristics of concrete mixtures used in laboratory placements. 31 14 Representative concrete unit weights. 56 15 Temperatures predicted using the Garison Method 64 16 Tremie concrete mixture, Pier 12, I-205 Bridge. 65 17 Maximum temperatures recorded in Pier 12 seal concrete. 71 18 Maximum temperatures grouped by instrument location 72 Temperature gradients in outer portions of seal concrete. 77 20 Predicted versus measured temperatures at various elevations. 21 Summary of concrete production for Pier 12. 78 22 Tremie concrete placement rates 95 23 Tremie concrete mixture, Wolf Creek Dam 97 24 Tremie resistance to flow measurements. 104 25 Variables used in example problem 110 26 Heat functions used for temperature predictions 110 27 Calculated flow distances 125 Introduction Bridges quantities approached30,000 yd3 3,000 m3! each! and the repair and recon- Whenmajor structures are built in s river, struction of the stilling basin for Tarbela Dam harbor, or coastal area, the underwater por- in Pakistan total placement of almost 57,000 yd3 tions of the structure usually require place- 3,000 m3! ment of underwater concrete. In some cases placement of underwater concrete is the only Among the deepest tremie placeraents are those of practicable meansof construction, while in the Verrazano-Harrows Bridge l70 fc! 2 m! other cases, it resy be the most economical or and the Wolf Greek Dsm cutoff wall 80 ft! expeditious mesne, 85 m! which is described in Chapter 4. Even deeper plscements have been made in mine shafts. In recent years, the device most frequently used for placing underwater concrete has been Although tremie concrete has proven itself on the tremie. A tremie is simply a pipe lang many projects, there have been s significant enough to reach from above water to che loca- number of unsatisfactory placements which tion of concrete deposition. A hopper is necessitated removal and reconstruction. Serious usually attached to the COpof the tremie CO delays, large cast over-runs, and major claims receive concrete being supplied by bucket, have resulted . pump, or conveyor. In most cases, the lower end of the tremie ie init'islly capped to exclude In light of the problems which have occurred water. Once the tremie is filled with concrete, during tremie placements, the Construction it is raised slightly, the end seal is broken, Engineering snd ManagementGroup at the Univer- and the concrete flows out embedding the end sity of California, Berkeley, has undertaken a of the tremie in s mo~nd of concrete, In major study of the tremie placement process. theory, subsequent concrete flows into this This study has two main objectives, The first mound and is never exposed directly to the is to establish criteria for mixture design and water. See Chapter 2 regarding this flaw placement procedures which will minimize the theory.! number of unsatisfactory events, The second objective is to facilitate snd encourage the One critical element af a successful tremie wider use of structural tremie concrete by placement is maintaining the embedmentof the insuring greater reliability . Achieving these mouth of the tremie at all times in the fresh two objectives will permit significant savings concrete . If this embedment is lost, water will in costs and time on major underwater construction enter the pipe and any concrete added at the projects. hopperwill fall throughwater resulting in severe segregation of aggregates and the wash- The work covered by this report consists of three ing out of cement and other fine particles, interrelated areas of investigation The first' Sucha segregatedmaterial ie unfic for either area considers tremie concrete mixture design a structural or nonstructural application.* and tremie concrete flow after leaving the tremie pipe . The second area considers tempera- In bridge construction tremie concrete hss long ture development in massive tremie placemants. been used ta seal cofferdams so that they may be The third area of investigation involved a pro- dewatered and the piers constructed in the dry, ject which, although not a mass underwater In such cases, the tremie concrete serves ss a placement, offered a unique opportunity to temporary seal and as s mass concrete base. examine a tremie placement at extreme depths Tremie concrete has also been used to plug the 80 ft SS m!! and which used s mixture suit- bottom of caiseone co insure full bearing over able for maes plscemente. The work performed the surface area. in each af these three areas of investigation is described in Chapters 1 through 6. Chapter 7 More recently, tremie concrete has been used contains conclusions and recorrnendatione relat- far the structure itself rather than just as a ing to all areas snd identifies areas requiring seal. In this application, the trcmie concrete additional study. Additionally, Chapter 7 is reinforced with pre-placed reinforcing steel. contains a recommendedpractice snd a guide This structural use has been applied to dry specification for massive tremie placements . docks, pump houses' snd especially to the piers of major over-water bridges, including the several ChesapeakeBsy Bridges, several Columbia The work described in this report was jointly River Bridges, and major crossings over San financed by the Federal Highway Administration Francisco Bay. FHWA! snd the University of California Sea Grant Program. This diversity of funding Among the largest tremie concrete placements are represents the diversity of applications for the east anchorages of the two Delaware Memorial the results of the work. The reconmrendatione presented apply to sll massive underwater con- crete placements whether for s bridge pier for a major highway or for a footing for an off- shore terminal. + For more inforsurtion on the tremie technique see references 1 through 5. Much of the work described in this report was connected with the construction ef the tremie concrete seal for Pier 12 of the I-205 Bridge over the Columbia River near Portland, Oregon An additional task covered by the FlgfA grant for this research project was to provide logistical support, through the State of Oregon Highway Department, to.three other groups of investiga- tors working at the Pier 12 site . These in- vestigations were aimed at determining the quality of the concrete in the seal by non- destructive methods. The specific investiga- tions were as follows; a. Lawrence Livermore Laboratory: Cross- Borehole Electromagnetic Examination; FHWA Purchase Order 47-3-0069, Task F. b . Ensco, Inc.: Short Pulse Radar Investiga- tion and High Enexgy Sparker System Investiga- tion; DOT contracts DOT-FH-11-9120 and DOT- FH-11-9422. c. Ho!osonics~ Inc.: Through Tx'ansmission Acoustic Surveys for Evaluation of Tremie Con- crete: MX contract DOT-FH-11-926g, Task D. The support received from Mr. Allan Harwood, Project Engineer for the State ef Oregon, 1-205 Bridge Project, and from Mr. Joe Turner, Resident Engineer, Cox'psof Engineers, Wolf Creek DamRemedial Work, is gratefully acknow- ledged, CHAPTER1 c! The gradation and type of the aggregate. SHALL-SCALELABORATORY COHPARISONS OF 2. Herschel ref. 7! listed four character- SELECTEDTREHIE CONCRETENIXTURKS istics which he thought defined the workability of a concrete mixture, These were "harshness, 1.l Ob'ectives. The objectives of this portion segregation, shear resistance and stickiness." of the project were to define the character- His paper included tests for each of these istics of a concrece mixture necessary for items as well as examples af the use of the successful placementby cremie snd to evaluate tests to evaluate a variety of concrete mix- several nan-traditional concrete mixcures which tures. appearedto have potential for use in tremie plscements. To accomplishthese objectives, a 3, Tattersall ref. B! in an exhaustive study variety of concrete mixtures meeting general lists five factors affecting the workability of guidelines for placementby tremie was compared concrete: to a reference tremie mixture using s series of standard and non-standsrd laboratory tests. a! the time elapsed since mixing: 1,2 Back round. b! che properti.ss of the aggregate, in par- ticular, particle shape and sixe distribution, 1.2.1 Workabiiic of tremie concrete. There porosity, snd surface texture; are two concrete characteristics generally regardedas critical for a successfultremie c! the properties of the cement, to an extent placement. The concrecemust flow readily and that is less important in practice than the it must be cohesive. In this case, coheaion is properties of the aggregate; thought of as that property which preventsthe concrete fram segregating as well as prevents d ! the presence af admixtures; the cement fram being washed out of the con- crete due to contact with mater. In practice, e! the relative proportions of the mix con- flowability and cohesiveness are usually stituents. achieved by adding extra cement,maintaining a low water-cement ratio and a high percentage of Tattersall cakes a rheological approach to fine aggregate, snd by having s high slump. measuring workability and argues that any of the cosxsonlyused tests for workability measure Unfortunately for the concrete technologist, only one aspect while measurementof more than these two desired characteristics are neither one is required. He writes that "at least twa easily defined nor easily measured. These twa constants are needed ta characterise the work- terms maybe replacedby the more general term ability of fresh concrete, and the two con- "workability" which is casssonly used to de- stants are dimensionally di f ferent. " scribe essentially the samecharacteristics far concrete which is placed in the dry. Although Tattersall concedes chat development of a it will be shown that workabi'ity is na easier practical test to determine these two constants ta measure than flowability or cohesiveness, is same time away. there is certainly s great deal of previous work to draw upon, Presentation of theories of the factors com- prising workability could ga on for somelength. An excellent definition for workability, which Tattersall alone lists l43 references. A includes the characteristics required far tre- sufficient sample has been presented to mie placement, was presented by Powers establish that there is s wide variscy of con- ref. 6!, "Qorkability is that property of s cepts concerningworkability for whichan plastic concrete mixture which determines the equally large variety of tests have been pro- ease with which it csn be placed, and the posed. degree co which it resists segregation. It embodies the combined effect of mobility and Based upon the work of the authors di.scussed cohesiveness." above and others!, the following conclusions were drawn for the present work; This definition is certainly not controversial. The difficulty arises in determining what pro- 1. There is no single test which will provide perties of s fresh concrete determine its work- definitive data on the workability of s ability. Fallowing is s brief sampling from concrere mixture. Any attempt to develop s the literature. single test for use with tremis concrete would probably be facile. 1, Powers ref. 6! listed three factors as defining workability: 2. The ease beneficial approach would be to apply s series of standard tests each measur- a! The quantity of cement-waterpaste includ- ing somecharacceristic of potencial tremie ing admixtures, if any! per unit volumeof cancrstes! and non standard tests designed concrete. specially to re late to crsmieplacement! to a reference concrete mixture snd the other mix- b! The consistency of the paste - which is tures of interesc. Behavior of the various dependenton the relative proportions and the mixtures in relation to the reference mixture kinds af material of which it is composed. cauld then be assessed. 3. The objective of the testing would be to 2. Unit weight. determine the significant characteristics required of tremie concrete, while simultaneous- Standard: ASTM C-138 CRD-C 7!. ly evaluating the selected mixtures, rather Frequency: One test per batch. than to develop a single recommended concrete Data Reported: Unit weight, lb/ft3 kg/m3!. mixture, 3, Air content presaure method! . Mich these conclusions in mind, s number of standard tests were reviewed to determine their Scandard: ASTM C-231 CRD-C 41!. suitability for use in this project. Several Frequency: Initially, two tests per four of the more coaaaon tests i. e., Powers ' Remold- batches. Later, two tests per three batches. ing Test! were eliminated prior ta beginning Dsts Reported.' Air content, percent. actual laboratory work due to their incompati- bility with concretes in the desired slump 4. Bleed ing. range. The tests which were selected are described in the next section. Standard: ASTM C-232 CRD-C 9!. Frequency. One rest per day. 1.2.2. Descri tion of teats erformed. A sum- Data reported: Total bleed water accumulation mary of the test program is presented in Table at 160 minutes + 10 min! after completi.on of l. The basic test plan was co subject each of mixing ml; bleed water as percentage of avail- the concrete mixtures to the selected tests able mixing water. three times. To insure objectivity, no mixture was tested more than once on a given day. 5. Compressive Strength. Due to capacity limitations in the laboratory Standard: ASTM C-39 CRD-C 4!. mixing equipment, each dsy's test of a particu- Frequency: Three cylinders x 12 in. 5.2 x lar concrete mixture required that multiple 30.5 cm!! were prepared from each batch. batches af concrete be produced. Initially, Remarks: Specimens were cured in accordance with four batches .8 ft each .05 m !! were ASTMC-192 CRD-C 10! and capped in accordance required. Later, after two tests had been with ASTM C-617 CRD-C 29! using a sulfur dropped from the test program, the number of mortar, Testing was accomplished at 7, 28, and batches required was reduced to three. Table 1 90 days. Gf the three cylinders made fram a also shows which testa were performed on each particular batch, one was tested st each age batch of concrete. Data Reported: Compressive strength, lb/in. MPa!. Par each of the batches of concrete produced, the Sump, unit Weight, air COntent two Of 6. Splitting Tensile Strength. every three batches!, snd temperature of the concrete were determined iaaaediately after Standard: ASTM C-496 CRD-C 77!. campletian of mixing. If these variables were Frequency: One cylinder x 6 in, ,6 x 15.2 within the correct range for the mixture being cm!! wss prepared from each batch. tested, the batch was accepted ss being repre- Remarks: Specimens were cured in accordance with sentative of that mixture. ASTM C-192 CRD-C 10!, Testing was done at 28 days. All concrete was batched snd mixed in accordance Data Reported: Splitting tensile strength, with ASTN G 192* CRD-C 10!++. As fsr as was lb/in.2 MPs!. possible, all tests throughout the test program were performed by che same individual to elim- 7. Time of Setting. inate any operator induced variations. Standard '. ASTM CW03 CRD-C 86!. A description of each of the tests in the pro- Frequency: One teat per day. gram follows: Data Reported: Time af initial and final setting, minn te s. 1. Slump test. 8. Relative Temperature Development. Standard: AS'TMC-143 CRD-C 5! Prequency: One test per batch. Standard: Mone Data reported' .Slump, in. cm!. Prequency: Two cylinders x 12 in. 5.2 x 30.5 cm!! per day. Remarks: Disposable metal cylinder molds were filled with concrete using the same procedures ss the compressive strength cylinders, Each mold contained a chermaeauple tied st the mid- point. Care wss taken during the concrete * ASTM test designations are from the Annual placement ca insure that the thermocouple was Book of ASTM Standards ref. 9!. nac disturbed. Sech cylinder was wrapped in s fiberglass insulation blanket and placed in a ae CRD-Ctest designations sre from the Corps of constant temperature room. Concrete tempera- Engineers Handbook for Concrete and Cmaent rures were recorded using a strip chart re- re f. 10! . corder and s digisl thermometer. TABLE 1 SUMMARYOF TEST PROGRAM+ Batch 2** Batch 3** Test and Standard Frequency Batch 1** Yes Slump 1 per batch Yes Yes ASTM C-143~ CRD-C 5th Yes Un i t Weigh t 1 per batch Yes Yes ASTM C-138 CRD-C 7 Yes Air Content 2 per day Yes No ASTM C-231 CRD-C 41 Bleed.ing 1 per day Yes ASTM C-232 CRD-C 9 Compressive 9 cylinders per day 3 cylinders 3 cylinders 3 cylinders Strength x 12 in. 5.2 x 30.5 cm!! ASTM C-39 CRD-C 4 Splitting Tensile 3 cylinders per day 1 cylinder 1 cylinder 1 cylinder Strength x 6 in. .6 x 15.2 cm!! ASTM C-496 CRD-C 77 Time of Setting 1 per day Yes No No ASTM C-403 CRD-C 86 Yes Temperature 2 cylinders per day Yes No Development x 12 in. 5.2 x 30.5 cm!! Nonstandard Slump Loss 1 series per day Yes Nonstandard Compacting Factor 2 per day Abandoned- NA NA British Standard no data reported! Yes Segregation 2 per day No Yes Susceptibility Nonstandard Yes Tremie Flow 2 per day No Yes Nonstandard Flow Trough 2 per day Abandoned- Nonstandard no data reported! *3 batches 1 day's test of a particular mixture 3 days' tests complete test of a mixture 3 3 *"l.8 ft .05 m ! OASTMtest designations from Reference 9 ttCRD-C test designations from Reference 10 Date Reported: Maximumtemperature increase Weight of concrete, large disc: B above mixing temperarure, degrees F degrees Weight of coarse aggregate, large disc: Ba C!; time to achieve naximvm temperature increase, Weight of concrete, small disc: A hours. Weight of coarse aggregate, small disc: As 9. Slump Loss. Hughes used the above data to define ehs Stability Factor as folIaws: Standard: none. Preqvency: One series of tests per day. SF Aa/A!/ Ba/B! Remarks:Approximately 0.5 ft3 .01 m3! of concrete was set aside from the first batch. Riechie used ehe same data to define the At specified times after mixing, a slvmp test Cohesion Index as follovs: in accordance with ASTM C-143 CRD-C 7! vas performed. Concrete used in the test wss re- CI B/A turned to the storage psn. The concxeee in the psn was rexxixed by hand prior to each test. Data Reported; Stability Pactor; Cohesion Data Reported: Slump, inches cm!; slumpas Index, a percentage of initial slump st T 15, 30, 60, 90, and 120 minutes after completion of 12. Tremie Plow. mixing. Standard: Hone. 10. Ccxspacting Pactor. Frequency: Two tears per dsy. Remarks: This test wss designed to simulate Standard: British Standard 1881:1952 ref. 11!. concrete flov through a eremie pipe. The This is nat s standard test in the United States. apparatus is shownin Pigures 4 and 5. Approx- Frequency: Two tests per day. imately 0.20 fc3 .006 m3! of concretewas Remsx'ks: Figure 1 shove tbe basic apparatus. placed into the tube in three layers. Each Concrete is placed into the top hopper and the layer was rodded 25 times ca produce s uniform flap is released alloving the concrete to dxop density fram test to test. After the concrete into the lower hopper. The lower flap is then was in place, the tube wss lifted until ehe released allowing the concrete co drop into mouth of the tube vss 4.5 in. 11.4 cm! above the cylinder. The concrete in the cylinder is the bottom af che pail allowing the concrete then etrvck off snd the cylinder is weighed. in the tube to flow into the pail Figure 6!. The cylinder is then refilled and thoroughly compacted, The ratio of the weight of the Af ter the flaw stopped, the distance from the partially compacted drapped! cylinder to the top of the tube to che tap of the concrete in weight of the thoroughly compacted cylinder is the tube vae determined. termed the compacting factor. More informa- Data Reported: Plov of concrete, in. cm!. tion on this test msy be found in the report of ACI Cosmittee 211 ref, 11! or in the vark 13. Flow Trough. of Mather ref. 12!. Data Reporeed. Hone, this test vss abandoned Standard: None. after initial experimentation showed that it Frequency: Two tests per day. does not discriminate well msonghigh slump Remarks: This test wae intended eo provide ~ concretes ef the nature of the mixtures being qualitative measure of the ability of a con- tested. crete to resist washing out of the cement vhen floving inta water, The appsrstve is shown in 11. Segregation Susceptibility Figure 7. Approximateiy 0. 1 fe .003 m3! af concrete wss placed into the tx'ough above the Standard: None. slide gate When the gate was lifted, the con- Frequency; Tvo tests per dsy. cxete wss intended to flaw into the vater and Remarks: This test wss a modification of that a qualitative estimate of cmsent washout was presented by Hughes ref. 13! snd later revised to have been made. by Ritchie ref. 14!. In the present case, Data Reported: Hone, this test wss abandoned the caspscting factor apparatus vss modified to after initial testing showed that no useful be used on this test by fabricating a cone snd data wss being obtained. tva wooden discs, The modified apparatus is shown in Figure 2, The test begins similarly 1.2.3. Descri tion of concrete mixtures ta the compactingfactor eeet by dropping con- evaluated. The first step in the selection crete into che bottom hopper. Then the con- of mixtures to test was the development of crete ie dropped onto the cone which caused it the standard or reference mixture. The mixture to scatter onto two discs. Ths cohesion of the selected wss based upon recosssendaeians from concrete controls the degree of scatter. Pig- the literature and upon the senior author' s ure 3 shave a sample af concrete after being personal experience on ~ number of major tremi ~ dropped on the cone. placemente. The basic elements of the reference mixture were: The weight of concrete on ehe small and large discs was determined. Then the concrete on Cement:7 1/2 sacks/yd3 05 lb/yd ! each disc wss wee sieved on s 1/4 in. .64 cm! 18 kg/m3! Water-cementratio: < 0.45. screen to obtain ehe coarse aggregate vhich was Fine aggregate: 45K by weight of taeal oven dried snd weighed. Thus the folloving aggregate. foux weights vere known: IO in 5,4 cm! UPPER HOPPER II in 7.9 cm! + I2.7 cm! 8 in IO in 0.3 cm! 5.4 cm! LOWER HOPPER 9 in 2.9cm! Sn I2.7 cm! 8 In 6in 20.3 cm I5.2 cm! CYL!NOER 12 in 0.5 cm! Figure 1. Schematic of compacting factor apparatus. UPPER HOPPER COMPACTING FACTOR A PPARATUS LOWER HOPPER CONK 9in 2.9cm! DIAMETK 5in 27cm! TALL UPPER m! 18in Dl A MK LOWER DISC 30 in 6.2 cm! DIAMETE R Figure 2. Schematicof segregation susceptibility apparatus. Figure 3. Concrete sample after performance of segregation susceptabllity test. LIFTING HANDLES SUPPORT COLLAR- CLAMPED TO PAIL AT THREE LOCATIONS METAL PAIL Il.5 in 9.2cm! INSIDE DIAMETER MOUTH OF TUBE IN RAISED POSITION TUBE- 4 in 0.2 cm! INSIDE DIAMETER 24 in 1.0 cm! TAL,L Figure k. Schematic of tremie flow test apparatus. Figure 5. Tremie flow test apparatus. Figure 6. Tremie flow test being performed. Tube is being lifted off of bottom of pail. 10 5 4J aj aj Q aj A0 OD 0 X CL 11 Coarse aggregate: 3/4 in. 9.0 nen! maximum. Their findings were: Admixture: Water reducer/retarder, in accord- ance with manufacturers reconnnendations. a. The addition of s small amount of bentonite Slump: 6 l/2 in. + 3/4 in. 6.5 cm + 1.9 cm!. .52 by weight of cemenc!gave the greatest retie of underwater to dry strength for the It is interesting to note that the character- cubes. istics of this reference mixture, which was derived from the experience of many engineers b. Larger amounts of bentonite up to 52! on a variety of tremie concrete plscements, showed improvements in cement wash-out at meet very closely the several requirements the expense of compressive strength for cubes listed above section 1.2.1! as indicating manufactured both above and belov water. good workability for s concrete mixture. Thus it appeared that bentonite sdditon or It must be noted that cwo of the items describ- replacement would be beneficial. Mixtures 7, ing the reference mixture, high slump and 8, snd 9 were developedto examinea vide range a Low water-cement ratio, could not be achieved of concentrations of bentonite. in sll of the mixtures evaluated. In those cases where there was a conflict, achievement The final groupof mixtureswse developed based of a slump in the desired range vas used as the upon experience in grouting where a chixo- determining factor. tropic agentmay be addedto thicken grouts. It wasbeLieved that suchan agent couldhelp Once the reference mixture wae established, a tremie-placedconcrete resist mashingout of the remainder of the mixtures in the program cement. A proprietary agent vas selected and were developed. Table 2 presents a emmnary used to develop Mi~tures 10 snd 11. Due to the of sll of the mixtures evaluated. Details extreme thixotropic behavior of these mixtures of each mixture design may be found in Appendix ss noted during trial batch preparations, the A. cementin Mixture ll wasreduced to 611 lb/yd3 62.5 kg/m3!in an effort to developa more The first group of mixtures Mixtures 2 and ecanomical mixture. 3! were direct variatians af the reference mixture which require no description. Due to problems with the behavior of Mixtures 10 and 11 which raised doubts about their The next group of mixtures wae developed sui,tability for use in a gravity feed cremie in response to the authors' concrern that situation, testing of these tvo mixtures was little, if any, consideration wse being given limited to one repetition only. The problems to problems of heat generation in massive tremie which developed are described below. placements. While much work has been done concerning temperature development in massive Description of the materials used in the test placemente done in the dry, as of the time mixtures may be found in Appendix B, of this testing, no such effort had been put forward for underwater placemente, 1.3 Observationsand discussion. Table 3 pre- The authars felt chat one af the techniques sents a smmnsry of the results of the tests for frequently used for reducing temperatureproblems all of the mixtures. Susnnaries for each mix- of mass concrete placed in the dry possolanic ture are in Appendix C while data from each replacement of s percentage af the cement of the individual tests performedare in would also be suitable for use in underwater Appendix D. Discussion of the results of the placements. However, unlike mass placements specific tesce is presentedin the following in the dry where tocel cementplus porzolan sections. This data should be reviewed with contents are very !ow, the pozzolanic replace- the thought in «ind that there were two basic ments for the candidate tremie mixtures were types of tests in the test program those in basedupon the original 705 lb/yd3 18 kg/m3! which s high ranking is believed to be indica- cement cancent since e harsh, no slump concrete tive of improvedperformance as tremie-placed would nat have been acceptable. Mixtures 4, 5, concrete and those in which the ranking is not and 6 were developed to evaluate potrolanic particularly significant. The latter type of replacements. test was included to insure that no anomolies in performancehsd beencaused by the various admixtures and additives. The next group of mixtures wae based uponwork published by The Netherlands Casenittee for Concrete Research ref, 3! describing research 1.3,1 Slum unit wei ht air content snd on admixtures to improve the quality of cremie- tern erature tests. The data for sll of the placed concrete: "The Cosnnittee vas on the mixtureswere within acceptableranges. The look-aut for sdmixturee which, as s result of following minor discrepancies were noted: exercising a 'g!ue-like ' effect, would give the fresh concrete better cohesion so that it 1. The slumpfor Mixture 9 wseslightly below would be lees severely attacked by vater." the stated range. However, this vae tolerated to prevent increasing the wster-cement ratio A variety of edmixcureswere evaluated primarily sny higher than 0,67 whichwss necessary to on the basis af two factors: the compressive achievethe 5.3 in. 3.5 cm! slump. strength of cubes manufactured above and below water; snd, the washing out of cement fram 2. The slump for Mixture 11 wss slightly above the concrete when dropped through water. the stated range. This was attributed to the 12 TABLE2 SUMMARYOP CONCRETEMIXTURES TESTED Water-cement No. Description* Ratio+* 0. 45 Standard Mixture reference! StandardMixture without WaterReducing/Retarding 0.46 Admixture Standard Mixture without Water Reducing/Retarding 0. 44 Admixture with Air-Entraining Admixture Standard Mixture with 20 Percent Replacementof 0. 51 Cement by Pozzolan StandardMixture without WaterReducing/Retarding 0. 53 Admixture with 20 Percent Replacementof Cementby Pozzolan StandardMixture with 50 Percent Replacementof 0. 62 Cement by Pozzolan StandardMixture with 1 Percent by Weight of 0.45 Cement! Addition of Bentonite Standard Mixture with 10 Percent Replacementof 0.58 Cement by Bentonite StandardMixture with 20 PercentReplacement of 0.67 Cement by Bentonite 0. 48 10 Standard Mixture with 1 Percent by Weight of Cement! Thixotropic Additive 3 3 StandardMixture less 94 lbs/yd 5.8 kg/m ! 0 ~54 Cementwith 1 Percent by Weight of Cement! ThixotropicAdditive without WaterReducing/ Retarding Admixture *Replacementsof cement by pozzolan or bentonite are given in termsof weightof cement. SeeAppendix A for mixturedetails. **Water-cement ratio is basedon weightof cementplus anyreplacement material. 13 TABLE 3 - SUMMARYOF MIKTURE EVALUATION TEST DATA Mixture Test Item 10* ll* Slump, in. cm! 7 ' 2 6.7 6.5 6.6 6.3 6.0 6 ' 6 6,7 5.3 6.8 7.5 18. 3 17.0 16.5 16.8 16.0 15.2 6.8 17.0 13.5 7. 3 9 ' 1! Unit Weight, lb/ft 150.6 150.5 142.4 147.1 146.4 140.6 150.3 145.2 140,4 145.6 147.6 k /m3 2413! 411 281 2357 345! 252 2408 2326! 249 2333 2365! Air Content Percent 1.6 1.2 6,9 1.4 1.3 1.3 0.9 1.3 4.6 2.5 Temperature, 'F 'C! 71 74 73 72 73 74 72 73 74 73 72 22 23 23 2 3! 23 22 23 23 23 22 Iremie Flaw, in. cm! 11..4 10,4 12,5 12.5 11. 5 12.4 9.4 11. 1 11.7 9.2 11.7 9.0! 6.4! 1.8! 1.8 29.2 31.5 3.9! 8.2 29,7 3.4! 9.7! Time of Setting, min initial 383 268 305 350 266 368 347 363 346 387 final 497 366 439 485 409 593 461 489 535 583 Bleeding, Percent of 2.4 2,1 1.7 1.6 0.9 0.6 2.4 1.2 0.3 0.0 0.0 Available Water Cohesion Index 0.07 0.08 0.01 0.04 0.05 0.00 0.06 0.03 0. 00 0. 10 0. 16 Stabilit Factor 0. 79 0.68 0.93 0.82 0.88 1.00 0,83 0.86 1.00 0.88 0.84 Temperature Development - max. increase F 'C 34 31 34 29 29 19 33 34 34 31 NA 9! 7! 9! 6! 6! 1! 8! 9! 9! 7! time to max. hours 19.0 15.1 15.9 17.6 15.8 16,5 16.9 16.6 14.4 21,6 CompryssiveStrength, lb/in. MPa! 7 days 4330 3750 2930 2790 2600 930 3990 2150 1420 3600 2600 9.9! 5.9! 0.2! 9.2! 7.9! 6.4! 7.5! 4.8! 9-8! 4.8! 7.9! 28 days 6140 5630 4320 5340 4950 2860 5640 3770 2520 5570 4680 2.3! 8.8! 9.8! 6.8! 4.1! 9.7! 8.9! 6.0! 7.4! 8,4! 2.3! 90 days 7300 6960 5390 6250 5850 4660 7040 4730 3180 NA NA 50.3 48.0! 7.2! 3.1! 40.3 32.1 8. 5! 2.6! 21.9 Splitting Tensi/e 745 720 630 675 660 435 720 535 395 NA Strength, 1b/10 MPa .1! .0 .3 4.7 4.6 3.0 . 0! 3. 7 2.7 Slump Loss, Percent of Original Slump Remaining T - 15 min 79 91 87 84 91 100- 61 88 92 96 91 30 min 78 83 87 80 82 92 64 78 86 96 94 60 min 55 72 82 69 76 78 57 67 60 100 63 90 min 50 62 77 66 64 64 55 54 42 76 47 120 min 42 58 68 53 59 50 42 43 29 80 38 MIXTURE INFORMATION Cementand Replacement3 Materials, Ib/yd> kg/m ! Cement 705 705 705 564 564 353 705 635 564 705 611 18! 18! 18! 35! 35! 09! 18! 77! 35! 18! 63! Pozzolan 141 141 353 84! 84! 09! Bentonite 8 71 141 ! 2! 84! Water-Cement + pozzolan 0.45 0.46 0.44 or + bentonite ratio! 0.51 0,53 0.62 0 45 0,58 0.67 0.48 0.54 Admixture A : Air entraining None P il P, T Water reducer/ retarder T = Thixotropic Data for mixtures 10 and ll based on one day's test only. Did not set within observation period; achieved only 150 lb/in.2 .0 Mpa! penetration resistance at 523 min. 14 difficulty of determining a slump versus mix" 1. Cohesion Index. The Cahesiaa Index was de- ing water relationship for an extremely thixo- fined earlier as tropic mixture. This difficulty in controlling the mixture by slump was one of the factors CI " 8/* ~hich eliminated this mixture from the complete test program. vhere B veight of concrete on the large disc A weight of concrete on the small disc 3. The air content of Hixture 3 was slightly above the planned level. The discrepancy was Thus the Cohesion Index is actually a measure accepted since it was nat large enough Co be of how veil the mass of concrete holds to- decrimental to the test program, gether. For a very cohesive mixture no con- crete would be found on the Large disc aud B 1.3.2. Tremie flow test. Table 4 presents a would be sera. Therefore, a Cohesion Index of ranking of the mixtures basedupon this test. 0.0 would be the best case; and, the mixcures The greatest flaw was given the highest rank- are ranked vith the dmaLLest Cohesion Index at ing. Six of the mixtures ranked higher than the top of the rankings, the reference mixture in this test. The tremie flow value does not appear ta be directly re- 2. Stability Fac'tor. Hughes ref, 13! defined lated to slump, as might be expected. The beat the stability of a concrete as its "ability to performancesvere from the air-entrained con- resisr. segregation of the coarse aggregate from crete Hixture 3! and che twa concretes with the finer constituents ~bile ia sn unconsolidat- the water reducer/retarder Hixtures 4 and 6!. ed condir ion" His Stability Fac t or was defined earlier as: 1.3.3 Time of sectin test. Table 5 presents rankings of the mixtures based upon borh initial SF Aa/A!/ Ba/B! and final setting times. The greatest time to achieve the defined penetration resistance where A sad B = as abave sett'ing! was given the highest ranking in each Aa = weight of coarse aggregate, small case. This ranking scheme should not be inter" disc. preted to meanthat greater times co achieve Ba = weight of coarse aggregate, large setting indicate more suitable tremie concrete disc. mixtures, If time of setting is determined to be significant for a particular tremie place- Each of the terms in the right side af the ment, it can be easily concralled by use of equation Aa/A and Ba/B! define the ratio of appropriate admixtures. the weight of the coaise aggregate in che saisple to the total weight of thar sample. If With the exception of Hixture 10, none of the chere is no segregation of coarse aggregate mixtures exhibited unsatisfactory setting during the tesr., the Stability Factor will be characteristics. Hixture 10 showed an extreme 1.0, the best case The mixtures are ranked in retardation due to the combined action of the order of decreasing Stability Factor. water reducei /retarder and the thixotrapic additive. This occurrence points out the The preferred performance af a trcmie concrete necessity for insuring that all admixtures are would be the highest ranking in eicher factor. compat ible. For the Cohesion Index all but three af the mixtures ranked above the reference mixture. 1.3.4 Bleedin test. Table 6 presence a rank- For the Stability Factor, all but one mixture ing for the mixtures based upon the percentage out performed the reference. Considering of available water lost through bleeding. The ' both tests, the best results were seen fai the highest ranking has been given ca the smallest ' 5OXpassolan replacement Hixture 6!, the 201 amount of bleeding. Based upon this criteria, bentonite replacement Mixture 9!, and the air- all of the mixtures bettered or equalled ane entrained concrete Hixture 3!. mixture! the performance of the reference mix- ture. Again, this ranking should not be inter- The poor rankins based on Cohesion Index for preted co meanthat no bleeding is necessarily ~ the two mixtures 0 and 11! containing the bet'ter for a tremie concrete mixture, gather, thixotropic additive vas surpi'ising and not it may be stated that none af the mixtures readily explainable. perhaps the energy devel- evaluated ~ould be expected to perform adverse- oped by the concrete falling onto the cone was ly based on this one factor. sufficient to overcame the chixatropic nature of the mixtures thus allowing a portion of the It shouldbe notedthat for certain applicationIsmass ca flaw onto the large disc. other than massive bridge piers or similar structures, large amounts of bleeding, may be 1 3.6 Tem rature develo nt test. Table 8 detrimental. One such case vauld be tremie- presents rankings of the mixtures based upon placed concrete used to fill a void beneath the increase in temperatbre after mixing. The base af an existing structure. smallest increase in temperature vas given the highest ranking. 1.3 5 Se re ation susce tibilic tests. Table 7 presents rankings for the mixtures base The mixtures are ranked essentially as vould upon the Cohesion Index and Stability Factor as be expected on the basis of cementicious determined in the segregation susceptibility material content. However, the twa mixtures tests. The basis for each of the rankings is concainiag the signi.ficant ~uncs of bentonite explained bc I owi !fixtures 8 and 9! show surprisingly large 15 TABLE 4 BANKIMGS, TBEMre FLOWTESTS TABLE 5 RAHKINGS, TIME OF SETTING TESTS* Initial Setting Final Setting Minutes Mixture Minutes Mixture 387 593 383 583 1 1** 368 535 363 497 350 489 347 485 346 461 305 439 268 409 266 366 * Mixture 10 had not achieved initial set after 523 min. Denotes mixtures which did not contain the water reducer/retarder. TABLE 6 RANKINGS, BLEEDING TESTS Bleeding, Nater- Percent Nixture Cement AvaiLable Ratio Mater 0.0 0.48 0.54 0.3 0.67 0.6 0.62 0.9 0.53 1.2 0.58 1.6 0.51 1.7 0.44 2.1 2e 0.46 2.4 0.45 : 0.45 * Denotes mixtures which did not contain the water reducer/retarder which promotes bleeding. TABLE 7 - RANEINGS,SEGREGATION SUSCEPTIBILITY TESTS Cohesion Index* Stabilit Factor** C. I. Mixture S. P. Hixture 0.00 ie s.oo 0.01 0.93 3 0.03 0.88 0.04 0.86 8 0.05 0.84 11 0.06 0.83 0.07 0.82 0.08 0.79 0. 10 10 0.68 0.16 eFor C. I., beer. ranking ia 0.00. **For S. P., best ranking ie 1.00. I7 TABLE 8 RANKINGS, TEMPERATUREDEVELOPMENT TESTS Temperature Increase Mixtures F C! 19 1! 29 6! 31 7! 10»» 33 8! 34 9! »Insufficient data were available for mixture ll *» Based on two cylinders only. TABLE 9 RANKINGS, COMPRESSIVESTRENGTH TESTS 7 Days 28 Days 90 Days> Water- Comp. Str., Comp. Str., Comp. Str ., lb/in.2 Mps! lb/in.2 MPs! Cement lb/in.2 MPa! Ratio 4330 9,9! 6140 2.3! 0.45 7300 0.3! 3990 7.5! 5640 8.9! 0.45 7040 8.5! 3750 5.9! 5630 8.8! 0.46 6960 8.0! IV 3600 4.8! 10 5570 8.4! 10 0.48 6250 3.1! 2930 0.2! 5340 6.8! 0.51 5850 0.3! VI 2790 9.2! 4950 4.1! 0.53 5390 7.2! VII 2600 7.9! 4680 2.3! 0.54 4730 2.6! VIII 2600 7.9! 4320 9.8! 0.44 4660 2.1! IK 2150 4.8! 3770 6.0! 0.58 3180 1.9! 1420 9 ' 8! 2860 9.7! 0.62 930 6.4! 2520 7.4! 0.67 Mixtures 10 and ll not tested at 90 days. temperature increases considering the reduced 1. The best performer, Mixture 10 thixotropic amounts of cement in chem. These two mixtuces addi tive and ws ter reducet/retarder! shoved also shoved shorter than typical times to extremely long set times due to an apparent developthe maximumtemperatures recorded see inCOmpatibiliey Of the tvo admixeures. The Table 3!, The cause of these anomalies is slow setting characteristics are sppsrencly unknown. Additional temperature investigations being seen in the slump loss performance. should be conducted prior to use of a high bentonite content mixcure. 2. The mixtures concaining bentonite , 8, 9! are sll grouped neat the bottom end of the A cour io» co»ter»ink this temperature dace rankings, must be raised. These cescs were intended to provide relacive comparisons of the various 3. The mixtures containing pozzolan , 5, 6,! mixtures only. The tests vere not adiabatic sre near the upper end of che rsnkings. Mix- and the data should noc be interpreted as ture 4, Lo«est ranked of the three, showed temperature incteases to expect in actual improving slump loss characteristics in che plaeements. See Chapters 3 and 5 concerning later time intervals 90 and ! 20 win!. temperatures in actual placemencs. 1.3. 10 Overall etformance. Of the various 1.3.7 Com ressive scren th tests. Table 9 tests performed, three are believed to be di- preaentS rankzngS Of the mSXCuresbaaed upOn rectly indicative of performance ss tremie- the compressive strength data. The highest plsced concrete: tremie flow, segregation ranking vas given to the highes c compressive susceptibility, and slump loss. A fourth "esc, strength. This data shove no surprises - the temperature development, may slsO be Signifi- mixtures are ranked as wou!d be expected based cant, depending upon the placemencsituation, upO» «ster-cement ratios Snd cementitious Table 12 presents a suiary of the performance material contents. None of the mixtures appears of the various mixtures on these four Cost's. to have been adversely affected by the various This table shows the ordinal rank ings of the chemical and mineral admixcures. mixtures on each of the four tests. The over- all rankings were determined by sussning the As «i.ch several of the other tests, a high rank- individual ranks. The invest total in the ing in compressivestrength doesnot necessarily surmsation «as given the highesc overall rank- imply that a concrete mixture is better suited ing. All four of the tests were weighted for tremie placement, The strength requited of equally co develop ehe ovetall ranking. the concrete should be a function of the par- ticular placement structural or nonstructural!. Based on this approach, the mixtures msy be listed from best to wots> performers as follovs: 1. 3.8 s litcin tensile stren ch test. Table 10 Mixture 6, 3, 4, 5, 9 LO, 8, 2, and 1 snd 7 presentss ranking of the mixtures basedupon tie! Hixtute 11, for vhich there was no splitting tensile strength. As for cOmpressive cemperacuredata, vould rank no lower than fifth screngch, the mixtures are listed in order of overall> and it would probably be somewhat decreasing, screngch. This data shows no adverse higher, Polloving are comments on the perfor- readings; sll of the mixcures achieved an appro- mance of the cop five mixtures. priate percentage of the compressive strength. 1, Mixture 6 OX pozzolan replacement with 1.3.9 Slum loss test, Table 11 presents the water reducer/retarder!. Although this rankings of the mixtures based upon slump loss concrete ouc did all others, it msy noc be chsrscteriscics, The highest rsnkings vere practical for use due co its slow strength gain given co the mixtures retaining the greatest characteristics. percentage of initial slump at each time incre- ment. A slow loss of slump indicating that the 2. Mixture 3 air-entrained!. Although perform- concrete is stiffening slowly would be benefi ing, well, this mixture developed higher temper- cisl in s cremie placement - particularly in a atures than did the mixtures containing pozzolan. large plscemenc «ith long flov distances. Therefore, it msy not be suited to all plsce- ments. Neatly all of che ~ixtures performed better chan che reference concrete on chi.s test - none 3. Mixture 4 0X pozsolsn replacement vieh vas ranked lower than the reference mixture at the water reducer/retarder!, Notes below vich sll time intervals. Mixture 5. An overall ranking for slump Loss performance 4. Mixture 5 OX pozsolsn replacement without msy be obtained by adding the rsnkings oi each the vaeer reducer/retarder!. Mixtures 4 and 5 mixture at each of the five time intervals. Xf showed quite favorable performances. There were the suamacions are chen ranked, the following hovever, minor inconsistencies in each: Mixture listing of slump loss performance best to 5 failed to tank highly in the eteaie flow tese worst! is obtained: Mixture 10, 3, 6, 5, 2, 4, while Mixture 4 vas somewhat lov in the segt'e- 11, 8, 9, and 7 and 1 tie!. gation SusCeptibiliCy test due to a low rank- ing, in the stability factor portion of chat 'h&ile the mixtures are a~what scattered in test. slump loss performance, the following generaL points may be made: 5. Mixture 9 OX bentonite replacement with tha vater reducer/retarder!. Although this mixture 19 TABLE 10 RANXINGS> SPLITTING TENSILE STRENGTHTESTS e Splitting Tensile Percent of 28-day Mixture Strength ib/in,2 Mpa! Compressive Strength 745 ,1! 12. I 720 .0! 12,8 675 ,7! 12.6 660 .6! 13. 3 630 . 3! 14,6 535 , 7! 14. 2 435 .0! 15,2 395 . 7! 15,7 Mixtures 10 and 11 not evaluated in this test. TABLE 11 - RANKINGS, SLUMP LOSS TESTS T 15 min.a T 30 min.e T ~ 60 min.~ T ~ 90 min.* T ~ 120 min.* Per- Per- Per- Per- Mixture Pez-«» Mixture Mixture Mixture Mixture cent** cents* cent** cent** cents* 100 96 10 100 10 1.0 96 10 94 Ilf 82 3f 76 10 68 92 92 78 66 59 5f 91 2f 87 76 58 1 lf I 86 72 53 5f l 83 2f 69. 62 50 88 82 st ' 67 55 87 80 63 54 42 84 [ 78 8 I 60 50 79 1 57 38 61 64 7 55 29 e Timesince completion of mixing. ** Percentage remaining of initial T - 0! slump. f Denotes those mixtures not containing the water reducer/retarder. 20 0 kJ A04g 0e 0 Cl 4i 44 O 4J I c4 W4 0 0 Jt '0 S 0 '0 4 O O 4 21 was ranked fifth overall, its potential for use I, Eleven different concrete mixtures were appears limited due ta poor performance on the evaluated far use in massive rremie placements. slump lass test. Additionally, this mixture These concretes included a reference mixture, was consistently ranked near the bottom in the an air-entrained concrete, several mixtures with compressive and splitting tensile strength eval- pozzolanic or bentonite replacements uf varying uations. amounts of cement, and two mixtures containing a thixotropic admixture. In general, the mixtures containing pazzolan seem to offer the greatest potential for use in 2. The concretes were evaluated using a series a massive tremie placement. The appropriate re- af standard and nan-standard tests which allowed placement rate between 20 and 50K! should be comparison with the reference mixture to be determined to meet the strength requirements of made, the in-place concrete. 3. The mixtures containing the pozzolanic re- In regard to the remaining mixtures, the fallow- placements and rhe air-entrained concrete were ing points may be made: the be"t overall performers. These mixtures out performed the reference mixture. 1. The reference mixture ! did not perform particularly well. 5either did the mixtures 4. The thixotropic mixtures achieved through vhich most closely resembled the reference, addition of bentonite or thixotropic admixture! Hixtures 2 and 7. It therefore appears that did not perform well and do not seem to be well it is practical and feasible to improve upon suited for massive tremie placements. the traditional tremie mixture design. 2. The addition of varying, amounts of benton- ite seems to have done little to improve the performance of the three concretes. Mixture 7 EX bentonite addition! was ranked ninth. Mixture 8 10X bentonite replacement! was ranked seventh. Mixture 9 0K bentonie re- placement! ~bile ranked fifth had low strength and poor slump loss behavior as discussed above. It is noted that mixtures similar to these per- formed best in the Dutch tests ref. 3!. 3. The addition of the thixatropic agent did not seem to offer any particular advantages. Mixture ll would have certainly ranked out of the top performers had temperature data been available. If only the three tests for which complete data are available for Mixture 11 are considered, it would rank seventh overall. Although Nixture 10 ranked sixth overall, its usefulness would be impaired by the long set time. Additionally, based upon these small-scale tests and the large-scale tests described in Chapter 2, it appears that the use of any thixotropic agent bentonite or admixture! may nat be appropriate for mass concrete placed by tremie. This con- clusion is based on two considerations. First, if a thixotropic concrete stops flowing due to a break in placement production, transpor- tation, etc.!, the material vill stiffen due to its thixotropic nature. Depending upon the geometry of the placement, to restart the con- crete flow may require significant energy in- puts. The veight of the concrete in the tremie pipe may not be sufficient to provide the re- quired shearing action to restart flow. The second consideration relates to the practical problem of controlling a thixotropic mixture. The temptation to add additional water to a ustiff" mix should be obvious. A pract ical means of controlling the concrete other than slump would certainly be necessary. ~14 S . Ih f ll g t these tests: 22 CHAPTER2 The tests were begun with the t remi e pipe de- watered the bottom was sealed with a plate. LARGE-SCALELABORATORY TESTS OF The plate and tremie! wt're initially resting TRK! 2. 2 B~kd. Dur irrg tire p lac»ment, thi fresh concrete was SumpI ed and t.< 2.2.~20 ' t' ~ 2 « t t 2 d. Th«small scale evaluations of concrete mixtures See references 3, 15, and 16. conduc Led earl ier Chapter 1! 'had shown that 23 Figure 8. Partially assembled tremie placement box. 24 Figure 9. Tremie placement box completely assembled and ready for placement. 25 Figure 10. Details of tremie hopper and pipe during a placement. The tremie has been raised by the fork-lift on the left and is blocked with the mouth 7 in. 8 cm! above the bottom of the box. Figure 11. Schematicof tremie placement box. Tremie p ipe is shownin the raised position. Elevation Note the overflow water from the view.!Figure12.Overallplacement view box.ofplacementoperation. 27 Figure I3. Taking soundings during break in concrete placement. TREMIE LOCATION OF CORES BO0 3I.5 57 9I l3I l5 l7 l920 .5! .9! I.5! . I ! .7! .4! .0! .6! .2! .8! .I! STATIONS, FT. m! Figure 14. Coring pattern for large-scale laboratory placements. Plan view.! 28 Figure 15. Tremie-placed concrete at completion of coring program. This sample is Test 1. Note core holes. mixtures containing pozzolans could be expected This statement clearly implies that newer to perform well as tremie-placed concr ece. The concrete should be found under earlier concrete results of those srsall scale tests and the de- at least until the tremie pipe is raised to cisions to use pozzolanic replacements in the star t the process over. concrete mixtures to be used for tremi e place- ments in a major cof cerdam seal Chapter 3! and 2. Halloran and Talbot writing in the Journal a deep cutoff wall Chapter 4! led to the selec- of the American Concrete Institute ref. 17! tion of a group of mixtures containing varying state: "As soon as the bottom cf the pipe tremie amounts of pozzolan far the laboratory large- was covered with concz'ete, the flow became an scale placements. extrusion from within and through che mass of concrete and not a flow over the tap of the In addition to the di ffering amounts of pozzolan, already placed concrete." two di f ferent water reducing, re tard ing admix- tures were used in the mixtures to determine the A figure in this paper shows that the concrete d ifferences, if any, in the performance of Lhe will be found in essentially vertical layers resulting concretes. para 1 lel to the tremie pipe. The newer concrete will be found in the layers closest to the pipe The mixtures which were tested were not selected with successively older concrete being found to model a mixture from a particular project. at greater distances from the pipe. Instead, as was done in the small-scale labora- tory tests, a reference mixt rre and several 3. Strunge, in a paper prepared for the Off- variat ions were developed . The reference mixtur'e shore Technology Conference in 1970, ref. 15! was the same as that used in Lhe small-scale wrote: "The principle of che method is co bring tests, Materials cement, aggregate, natural the concrete through a pipe to the interior of pozzolan! were from the same sources as for the the concrete being poured, thus preventing con- small-scale tests. Table 13 shows the properties tact with che surrounding water." of the mixtures used in the large-scale tests. Fig~res in this paper, based upon small scale 2. 2. 3 Flow of tremie concrete. The subject of flow tests, show bulbs of concrete surrounding tremic concrete flow pat cerns has at erected a L.remie pipe. Successive concrete forms new many researchers, probably due to the relation- bulbs which force the older concrete away f.rom ship between concrete flow and laitance formation the pipe. Again, the end result is concrete which is a measuz'e of the quality of tremie which is layered vertically. conczete!, A wide variety of reports and pro- posed flow schemes may be found in the litera- 4. Wi 1 1iams, also writing, in the Journal of the ture. A summary of severa 1 of these reports American Concrete Institute ref. 18!, described follows: model tests in which seven batches of 0. 75 ft3 .02 m ! each weze placed at 20minute inter- The initial concrete which flows out of the tre- vals. Figures in this papez show definite hori- mie builds up a small mound at the mouth of the zunLal layering. Williams reports for one mix, pipe. I c is this mound which seals the tremie "Part of che mix 'rolled ' down the steep s lope,." for subsequent concrete flow. This initial con- crete is in direct contact with water and is The intervals between the batches apparently che most susceptible to washing and segregation; necessitated raising the cremie pipe which therefore, it contributes the mosc ro the forma- could have contributed to the layering notrd. tion of laitance. Subsequent concrete has been assumed to flow into che concrete rsass and there- Additional examples could be cited, bur these fore nat be subjected to direct contact with the should be sufficient to establish that a digree water. In same manner usually unexplained in of uncertainty exists concerning Cremie concrete the reports! the initial concrete mass expands flaw patterns. It was felt that the large-sca!e so that all of the later concrece flows into tests would be beneficial in providing addition- concrete and is nor exposed to che water. This s! information on this subject. theory implies that the first concrete p1aced should be found abave some or all of the concrete 2. 3 Observat ians and discuss ion which is placed subsequently. Clearly, there must be some Limit to this concept since the 2. 3.1 Direct observations of concrete flow initial concrete volume undefined! can only be This section is based upon visual observations stretched so far. Fuzther, this inicial con- made during the f ive placemencs, This informa- crete would ultimately set making additional tion is intended to describe only a portion of expans ion impossible . the flaw phenomenon. Following sec tions wil 1 add additional information. Several i'epresentative repar ts fram che litera- ture followr' Two significant items were observed during the placements: l. As was expected, there was an I, The Arserican Concrete Institute in its immediate flow which occurred as soon as the Recommended zac tice far Neasurin Nixin tremie pipe was lifted. This flow was made up Trans ortin and Placin Concrete Ref. 1! af cwo components. Firsr., there was a flow of achates: "Tremie conc~ate flows outward from the concrete which quickly established a mound bottom of the pipe pushing the existing sur face around the mouth of the pipe, Second, there of the concrete outward and upward." was a flow layer of a colloidal suspension of 30 TABLE13 CHARACTERISTICSOF CONCRETEMIXTURES USED IN LABOEATORTPLACEMEHTS 28-day Comprgseive Strength Pozzolan Unit Cement Pozzolan Slump, lb/ln.r Mpa! [Note 6] Content Air Weight Concrete Content Contempt Aumixt itres in. Percent Content lb/ft3 Standard Test Rite Mixture lb/yd3 lb/yt[3 cm! hg/m3! kg/m~> Bv Weight kg/m3! Cured Cured [Note 1] [Note 2] [Note 3] [Note 4] [Note 6] [Mote 7] 1 705 7.3 0. SX 154 5,390 5,190 Standard! 18! 8.5! ,470! 7.2! 5,8> 353 353 50 6.8 2.3X 142 3,560 3.030 ' 09! 09! 7.3! ,270! 4.5! 0.9! 528 176 25 7.3 1.2X 142 2,910 2,510 13! 04! 8 ~ 5> ,270! 0, 1! 7. 8> 705 0.4X 147 5,270 4,960 18! 9.1> ,360! 6.3! 4.2! 528 176 25 a andb 9.4 0.4X 147 5,470 5,020 13! 04! [Hots 5] 3.9! ,360> 7.7! 4.6! 'NOTES: 1. For all mixtures: 5. Both admixtures inadvervently added to this mixture. Fine aggregate 45 percent of total aggregate by weight - Maximum water-cementitious material ratio: 0.45 6. Average of three samples ~ - Design slump: 7 inches 8 cm! 7. Cylinders sealed and stored next to Maximumaggregate: 3/4 inch 9.0 sm> placement box until capped snd tested. 2. Cementwas Type II manufactured by Kaiser. 3. Pozzolsn wsa a natural material meeting requirements of ASTM C618, Type H. 4. Admixtures: s. Water reducer/retarder; 'Master Builders Pozzollth 300R, b. Water reducer/retarder: Sike Plastiment, 31 fine psrtic!ee v!Lie|< traveled Very rapidly tp 2.3,2 Flow durin Lacement as determined b the far end of the placement box. These par- ~ ou~d~aaa. da deec 'ddd ea d ' td t c tic1ee vere apparently cement graf'ns which vere procedure, each test of 6 yd .6 m ! was 'wa'dh'edaut of the concrete that initially flawed broken into three approximately equal segments aut of the tremie. The presence of the flow by volume! which vere colored differently. '-'layer vas unanticipated, and th'e speed of the Betveen placing each of 'the segments end also flow'was eurprising the layer wss seen at the following the final segment, soundings were taken fax end of the box 7.5 ft .3 m!! within at 20 points witkin the test box to determine several seconds. concrete flow patterns.. The soundings points were located as is shown in Figure 17. Concrete Due co the, collaidally suspended particles, the thicknesses as determined by the soundings are density of this flaw layer was such that it in Appendix K. remained as a cloudy layer on the bottom of the box. As the placement progressed, additional The soundi.ng data have been used to drav center- p'articles Vent ifd'tXxsuspension, and the identity line profiles for each of the teste Figures !8 of the or-'ginaL-qeyer wse vieue}.1y obscured' through 22!. Plotting of these data showed very little lateral variation in the surface of The speed at which .the cOL oidal layer CraVeled the concrete during the placements; therefore, no proved ta be directly related to the speed at cross sections are presented. .which the cremie pipe was raised to begin che placement.. The faster the pipe vae raised, It must be noted that concrete for these tests the faster the layer f!oved to the far end of was purchased from a resdy~ix .supplier. There- the plscemenx box. fore, the quantity of concrete placed may have varied slightly fram test to test. Also, the These observations of the flov from the tremie first test wss conducted using a concrete pump pipe indicate an initial radial flov of sub- t Equally important, if a tremie were being 1. This evaluation of soundingsdose not show restarted in fresh concrete as vould happen which roncrete is in which layer only the when tremies are relocated during a large place- relative thicknesses during the placement. ment!, the rapid flow observed could contri,bute Identification of specific concrete can only be to washing the surface of the existing concrete accomplished from the cores. The profiles must and thus increase laitsnce. not be interpreted as successive Layers of differently colored concretes. 2. The second observation concerns flow of the concrete after a mound of concrete bae built up 2. All of the mixtures showed the same basic around the mouth of the tremie pipe. During the flov pattern. The differences were in the degree first three tests, concrete vas seen to be flow- of maundingat the tremie lacatian, the ovex'-all ing verticaLly up alongside the tremie pipe, slope of che concrete, the amount of concrete Once a sufficient amount of fresh concrete had which reached the far end of the box, and the built up around the tremie, the concrete appear- rate at which concrete reached the far end. The ed to slough aff similar to a soil elope fail- soundings do not indicate whether the concrete ure!, !n these instances, cbe concrete may have «as flowing into or over the existing concrete.. pushed the earlier concrete away from the tremie pipe, or it may have simply flawed over the 3. The first three tests produced results which earlier cancrete Figure 16!. Due to the tur- were quite similar. For all three chere «as bidity of the water from the colloidal suspen- significant maunding near the tremie location sion, the exact mechanisms of flaw could not be Figures 18, 19, 20!. As a result of this mound- accurately determined. ing, very little concrete reached the far end of the placement. Rane of the three mixes appears Ix shou!d be noted that these teste were essen- to have a distinct advantage over either of the tially continuous placements. They vere con- other tvo. ducted quickly enough to prevent excessive stiffening of the first concrete placed before 4, The final tvo tests were quite similar and rhe 'est vsc completed. showed a drastic difference from the first three teste Figures 21 and 22!. The woundingwas these visual observations indicated a complex essentially eliminated, the overall surface flow mechanism which may be a combination of elopes vere much flattex, and s much greater come ar all of these noted abave. The obeerva- amount of concrete reached the far end of the tiax 32 a. Observed flow parallel to tremie pipe. b. Postulated flow over base concrete after build-up in "a", above. c. Postulated flow into base concrete pushing older concrete away from tremie after build-up in "a", above. Figure 16. Observed and postulated flow of concrete near tremie pipe. 33 TREMIE CONCRETE FLOW SOUNOING LOCATION AND NUM8ER 10 C. eo Figure 17. Soundinglocations in tremieplacement box. Planview.! TREMIE 4 I 2! E 3 CO .9! 2 > .6! L4J ~ .3! O 0 IO l5 .0! .6! STATIONS, FT. m! Figure 18. Yrenieconcrete profilea duringplacement, along centerline of box,Test l. 30 TREMI E SECTION, SECTION, 4 I.2 ! E 3 <0.9! O > <0.6! ILI I O Q3! O .0! ,6! srArioNs, FT. m! Figure19. Tremieconcrete profiles during placemeut, along centerline of box,Test 2. TREMI E SECTIONr SECTION, FIG. 4I FIG. 42 4 I.2! E 'P ~ .9! O 2 > <0.6! ILI I O 3! O O I.5! .0! <4.6! STATIONS, FT. m! Figure 20. Tremie concrete profiles during placement, along centerline of box, Test 3. 35 ggCTIONi mcaei ggC" TREMIE FIe. Sg via 44 4 .2! E I-' 3 v! ,9! LJJ R O Z e6! Z'O .3 O 0 1.5! .0! .6! .I ! STATIONS, FT. m! Figure 21. Tremie concrete proofiles es during n placement, alongalon cencenterline of box, Test 4. TRDII IE 4 2! E ri! .9! CO P .6! I- UJ K O .3! D O 00 5 10 15 20 I.5! .0! .6! .1! STATIONS, FT, mj Figure 22. Tremie cori. rate pro files during placement, aalon ong centerline of box, Test 5. 36 5, On the basis of the flow during placement, of water reducer/retarder would have been per- rhe governing factor appears to be the addition ferable in an actual placement. of the second type of water zeducer/retarder, regardless of whether pozzolan was incorporated 5. The mounds at the tremie location in the into the concrete. When the mixtures are cate- first three tests were very similar to the gorized as containing or not containing the mounds seen on the tremie seal discussed in second type of water' reducer/retardez, the mix- Chapter 3. ture with pozzolen performed as well as the reference mixture in each category. 2,3.4 Oistribution of concrete colors. As is described above tn the test procedure, exten- 2,3,3 Surface rofiles and surface a earance sive coring of the tremie-placed conc~ate was In addition ta the soundings described above, accomplished to determine the final distribu- e detailed mapping was conducted over the surface tion of concrete by its colors. The coring of the concrete samples after the bax wes de- pattern used was presented earlier in Figure wetered 20 date points versus 20 for the 14. soundings!. Measurements were made to deter- mine the concrete thickness at five locations The information obtained from the cores was laterally outside edges, 12 in, 0.5 cm! fram correlated with the overall profile data to outside edzes. and centerline! and at every 1 ft produce approximate profiles of the color dis- 0.5 cm! interval along the long axis of the tribution along the centerline and right edge box. The data obtained from these measurements af the placement box. These profiles are are in Appendix F, Pzofilea Showing the concrete presented in Figures 34 through 38. The data thickness along the centerline and one edge are upon which these profiles are based are given given in Figures 23 through 27. These profiles in Appendix G. are included since they show a much more detail- ed view of the concrete sur face than do the The following considerations apply to these soundings. Since there is very little lateral pro files: variation, no cross sections are presented. l. In several instances less than complete photographs of the sur faces of the five tests recovery of cores was obtained. These cases are in Figures 2S through 33. A close-up af were believed to be due to caring problems the surface of Test 1 is shown in Figuze 29. rather than sand layers.! In these cases thicknesses of colors were approximated from The following paints may be made frors the surface the portions of cores z'ecovered end fram tot'al measurement data: sample thickness data at the point of coring. 1. The profiles reinforce what was noted from 2. The quantities of concrete of a given color the soundings concerning mounding and concrete mey have varied slightly fram test to test. flow to the far end. Additionally, the surface However, the sequence of colors wes always the measurements show that the most severe mounding same: gray/brown depending upon pozsolan occurred dizectly under the thremie pipe for content!, red, and black. Tests 1, 2, and 3. Obviously, some of the mound- ing was caused by the withdrawal. of the pipe. 3. Except for minor variations caused by flow around reinforcing steel described below in 2. The photographs show the surface appearance section 2.3.6!, tbe color distributions were to be very similar for the first three tests. quite syrmsetrical across the short dimension In these tests, the concrete surface was ex- of the placement box. Thezefore, only one tremely rough, with Test 1 being the roughest. edge profile is shown, Figure 29 shows the developmenCof ridges per- pendicular to the flow direction in Test Several blocks of concrete from these tests These ridges were not seen in any of the other were cut with a wire saw ta provide e more tests. The appearance of the ridges seems ta graphic representation of the coLor distribu- indicate that the mass of concrete was being tion. Photographs of these cross sectiorrs ere pushed away from the tremie es additional con- presented in Figures 39 through 45. crete was being added. The following poi.ts may be made concerning the 3. The surface profiles of the concrete for concrete flow pattern as determined by the color Tests 4 and 5 were also very similar and showed distributions: e significant improvement over the fzrst three tests. Both tests showed much smoother and 1. Ha single flow pattern wes seen which would more uniform surfaces than the earlier' tests. establish one of the theories described above section 2.2.3! as the characteristic tremie As was true with the soundings data, the flow mechanism. Several mechanisms appear to sur face profiles end surface appearance appear be invol.ved. to be e function of the admixtures used. The presence of the pazzolen does nat appear to 2, The color distributions do not substantiate have a significant influence. However, in the flow descriptions of the type which hold that first three tests the two mixes containing poz- the initial concrete is pushed upward by con- zalsn did provide slightly smoother surfaces!. crete placed subsequently. Concrete of en Based upon the surface profiles and textures earlier color was found above later concrete obtained, the mixes containing the second type in only a few minor instances. These in- 37 7REMIE 4 E I.2! Co to .9! 4J O 2 X .6! LL! K I ,3! 0 0 5 IO l5 !,5! ,0! .6! STATIONS, FT. tm! I'igure 23. Centerliue aud right edge surface profiles, Test l. TREMIE SECTlON, S 4 l.2! 4 3 ,9! V! hl O 2 X I- .6! Lal I- K I .3! O O < I.5! .0! .6! STATIONS, FT. e! Figure 24. Centerline and right edge surface profiles, Test 2. 38 TREMIE &CTIONq ZIJ .6! I- I ~ ,3! z O O .0! STATIONS,FT. m! Figure 25. Centerline and right edge surface prof iles, Test 3. TREMIE SCCTION, 8CCTION 4 I.2! l-' 3 lO Q9! CA 4J X hC O 2 T .6! I- l- W KI .3! O O 0 I 5! 0! 6! STAT!ONS, FT. tltl! Figure 26. Ceaterliae am! right edge surface profiles, Test i. 39 TREMIE 4 I.2! 3 ~ .9> O ~ o6> LLj I .3! z 0 O 'o S IS 20 I.S! .0! .6! . I! STATIONS, FT. m! Figure 27, Centerline and right edge surface profile, Test 5. 40 Figure 28. Concrete surface, Test l. Figure 29. Close-up of concrete surface, Test l. 41 Figure 30. Concrete surface, Test 2. Figure 31. Concrete surface, Test 3, 42 Figure 32. Concrete surface, Test 4. 43 Figure 33. Concrete surface, Test 5. 44 TREMIE I.2! 3 .9! 2 .6! LL .3! LIJ z 0 IO 15 20 O L5! 0! .6! . I ! 4 I.2! LLI 3 ~ .9! O Z 2 0 .6! O I .3! '0 10 IS I.S! .0! ,6! . I! STATIONS, FT. tm! figure 34. Color distribution, Test l. sscTIOH, TREMIE Fls.$9 FIO.IO I.2! 3 .9! 2 .6! .3! IJj Z p Y O I.S! 0! .6! e,l ! 4 I- .2! I- 3 g .9! O Z2 O ,6! I .3! Op 5 IO l5 20 I,S! .0! .6! I! STATIONS, FT. m! Figure 35. Color distribution, Test 2. 45 etCllON, sKCTON, Fle. el Fle. st TREhIIE < I,2! 3 .9! 2 .3! UJ Y 2 0 O .9! O2 2 0 0 5 IO l5 < I.S! .0! .6! STATIONS, FT. m! Figure 36. Color dZstrfbution, Test 3. SECI'ION, 8ECTIoN,Kc f else TREII IE fle. eb Ro. 41 Fls. ss l,2! 3 .9! 2 .6! I- U .3! CO ztLI 0 Y I.5 4 < l.2! 3 ~ <09! O .6! 0 I .3! 0 5 IO l5 I.S! .0! .6! STATIONS, FT. m! Signore 37. Co1or distribution, Test 4. 46 TREM IE I. 2! 3 .9! 2 ,6! I ' U I - 3! ILJ 0 0 5 10 20 I.s! .0! .6! .1! 4 .2! hJ .9! O .6! O I . 3! 00 s 10 I.s! .0! .6! . I! STATloNS, FT. m! Figure 38. Color d istr ibution, Test 5. 47 a. Photograph with boundaries between colors enhanced. b. Schema t ic . Figure 39. Gross section, Test 2, 8 ft .0 m! line. a. Photograph with boundaries between colors enhanced. b. Schematic. Figure 40. Crosssection, Test 2, 12 ft .7 m! line. a. Photograph with boundaries between colors enhanced. Exact division between red and brown not visible on this photograph. b. Schematic. Figure 4l. Cross section, Test 3, 8 f t .4 m! ifne. a. Photograph with boundaries between colors enhanced. b. Schematic. Pigure 42. Cross section, Test. 3, l2 ft .7 m! line. a. Photograph with boundaries between colors enhanced. b. Schematic. Figure 43. Cross section, Test 4, 8 ft .4 m! line. 52 a. Photograph with boundaries between colors enhanced. b. Schematic. Figure 44. Cross section, Test 4, 12 ft .7 m! line. Note reinforcing steel. 53 a. Photograph with boundaries between colors enhanced. b. Schematic. Figure 45. Cross section, Test 4, 14 ft .3 m! line. Red colored concrete is offset due to flow around reinforcing steel. stances were of the nature of that shown in 9. Item 2, above, indicates chat the general Figure 43. It appears that these instances are notion of concrete flowing into an existing "noses" of concrete pushing into earlier con- moundsnd thus being protected fran contact crete. They are probably the result of the vith the water may not always be correct. In formation of bulbs of concrete around the the layer type of flaw, there is s significant mouth of the Cremie. The sides of the place- chance that most of the tremie concrete vill be ment box eisa may have had s role in the forma- exposeddirectly to water during the placement. tion of these areas by reducing lateral flaw. 10. It wss pointed out earlier nat to equate 3. Two basic flow mechanisms seem ca be pre- soundingdata with color layers. The need for sent in these tents. With the exception of that warning csn be seen by comparing the Test 1, the mixtures can again be categorized figures shoving soundingdata with those showing by the presence of the second type of water color distributions. Concrete from the first reducer/retarder.! In Tests 2 and 3, the pattern color placed continued to moveas additional seems to be hocizontal layers with the later concrete was added. Apparently, tremie concrete concrete flaming over earlier concrete. In msybe expeccedto be movingfor a longperiod Tests 1, 4, and 5, the pattern appears to in- of time after it exits fram che tremie pipe. dicate that later concrete was pushing earlier concrete svay from the tremie rather than ll. Althoughthe coring, programdid provide flowing, over it. valuable data, it was extremely time-consuming, difficult, snd expensive, Developmentof an 4. The color distributions af Tests 2 and 3 alternative approach,if investigationsof this support the earlier COmments SeCCiOn 2.3.1! nature sre undertaken in the future, is highly describing flow bsck-up alongside the tremie reconmmnded. pipe, before lateral fLow took place. For these tests, the concrete could have flowed 2.3,5 Concrete densit . The cares obtained upward first and then down snd aver the ear- from the last four placemencsvere also used to lier concrete creating the horizontal Layers evaluate the density of the in-place tremie con- noted. crete. Density and unit vei,ghc vere determined according,co the following formula: 5. The data from Tents 4 snd 5 could also w support the concept of flow backup alongside s and parallel to the cremie pipe. However, if Unit weight v v 'Y v this vere the cane, the flaw after the upward s rise vas probably essentially a shear failure vhere w weight in air which caused s movement of the entire mass a away from the tremie pipe. Since mixtures 4 snd 5 contained the second type of water reducer/ w ~ weight in water retarder, there may have been less shear re- unit veight of vater sistance in the fresh concrete. 6. Perhaps s better theory for Tests 4 snd 5 Selected data frcxn these calculations sre pre- is che formation of s bulb of concrete around sented in Table 14. Unit veigbts of fresh the tremie pipe. Rather than flowing upward, concrete calculated in accordancevith ASTN nev concrete would simply push earlier concrete C-13B are also presented in this table for com- sway from the tremie. Again, this theory parison. would depend upon the lovered shear cspaciry of the concrete in these tests. This theory The following points msybe madeconcerning the vould also account far the small amounts of concrete densities: red concrete found aver black concrete. l. In-place unit weights for concrete at the 7. The data for Test 1 sees to fit the bulb location af the tremie were very close to pattern described above, except that upvard flow those determined for the fresh concrete by the alongside the cremie »as detected during this standard ASTN test. Differences for the four test. This mixture did not contain the second tests rangedfrom O.L ta 2.2 percent with the type af water reducer/retarder. It must be noted in-place concrete being heavier in all cases. that Test 1 was conducted by pumping che concrete Thus, the process af flowing through the rre- from the truck co the cremie hopper. The incre- mie does produce s dense concrete near the mental volumes of concrete placed and thus the cremie pipe. changesin color! were determinedin a muchmore approximate and inaccurate manner than during the 2. There is a general decrease in concrete other tests. These inaccuracies msy make close unit weightas distance from the tremie in- CamperinOne With the Other testn somewhatin" creases. When the effects of laitance accumu- lation on the surface are neglected by using appropriate. cores not affected by the laitance, chis de- 8. It is interesting ca note thee ridges were crease is not significant, as is shownbelow seen on the surface of Test 1 ac approximately smounts of laitance accumulation are discussed the 9 and ll fc .1 and 3,4 m! lines. The in section 2.3.7, below!: ridges csn be interpreted, on the basis of the color distribution, as being farmed by the red COnCrete puShing the gray COnCreteSway frOm the tremie. 55 TABLE 14 - REPRESENTATIVE CONCRETE UNIT WEIGHTS SEE FIGURE 14 FOR CORE LOCATIONS Unit Weight Tes't Station Depth* 3 3 lb/ft ~g/~ ! 142.0 2,263 2r207 2,212 2,212 2 195 ASTM C 138 147.0 2 355 ~Indicates cores which included surface laitance. No entry indicates core was recovered full depth in one piece. Bar s Teer. At Tremie Core 13R, bottom, 147.2 lb/fc3 358 kg/m3! 2 14 1. 3 lb/fc 263 kg/m ! Bar s 3 143.1 lb/fr. 292 kg/m ! Coze 15R, bottom, 148.2 lb/ft 374 kg/m ! 4 145. 5 lb/ f t3 331 kg/m3! 5 145,2 lb/ft3 326 kg/m3! The change in density caused by the reinforc- ing steel does not appear to be significant, Test Station At Station as long as lsitance is not trapped near the steel. 2 15 137.0 lb/fr, 195 kg/m ! 2.3.6. Flow around reinforcin steel. Rein- 3 15 138.1 lb/ft3 212 kg/m ! forcing steel was placed in four of the tests to simulate reinforced tremie placements. 4 19 142.1 lb/f c3 215 kg/m3! Obsez'vations vere zsade of the flow of the concrete around these bars. 5 19 145.8 lb/ft 335 kg/m ! For Tests 1 snd 2, the bars were placed in a 3. When laitance is included in the cal- rov across the end of the placement box. For calculations, the decrease becomes much greater. Tests 4 snd 5, che bars were assembled into a The data below are for cores which had a cage along the side of the box. Details of surface layer of laitance. the bar placement are in Figure 46. Test 3, Core.19L ~1,5 in. .8 cm! The material reaching the end of the box in laitance!: 127.9 lb/fc 049 kg/m3! the fs.rsc two tests was largely lsitance. Test 5, Core 19R ~3.0 ln. .6 cm! This material did flov well around the bars but it would not have provided satisfactory laitance!; 134.6 lb/ft 156 kg/m ! bond had these been actual placezsents. Fig- ure 47 shows flow around bars in Test 1. It may be argued that some of the lsitance resulted from an "end-effects" phenomenon as Moving the bars closer co the trezsie pipe the concrete reached the end of the placement resolved the laitance problems and allowed box. However, the same effects vill occur in more valid observations of concrete flow actual placements as the concrete reaches the around the steel, The results were extremely boundaries of the placement. Therefore, these good, as shown in Figure 48. While the bars data reemphasize the requirement for removal had very little influence on the concrete, of washed material at the far end of a place- there were two noticeable effects. ment to insure thee such material does not become trapped in or part of the final cOn- 1. There was a minor buildup of concrete crete product. upstream of the bars, as can be seen in the profiles along the right edge given earlier. 4. As is described below, flow of tremie con- This buildup was on the order of a few inches crete around reinforcing steel vas also exam- and would cause no problem in an actual place- ined during these tests. Flow around the bars ment. seems to have little effect on the concrere density as is shown below: 2. The bars did cause concrete flow to skew away from the steel. This is clearly seen in Test 4 Figure 45. Although interesting, rhis phenom- enon would not affect the quality of the Coze 9R, bottom, 146.8 lb/ft 352 kg/m ! concrete. Core llR, top, 144.5 lb/ft 315 kg/m ! Overall, concrete Tests 4 and 5! flowed well and embedded Che bars sar.isfactorily. The Bars slight buildup behind the bars reemphasizes the necessity for carefu! detailing of re- Core 13R, bottom, 147.1 lb/ft3 357 kg/m3! inforcing steel for tremie applications to insure wide enough spaces for the concrete to Bar.s flow through. There was no difference detected in the flow and baz. embedment betveen the Core15R, top, 136.8 lb/fc 192 kg/m3! concretes with and without the pozzolan. includes surface laitance, 3.0 in. .6 cm!! 2,3.7. Leitance formation. One area which Test 5 is always of concern during a trezsie place- ment is the washing out of some of the cement Core 9R, bottom, 149.0 lb/ft3 387 kg/m3! paste from the concrete and the subsequent formation of laicance. The fear of this Core 11R, bottom, 147.7 lb/fc. 366 kg/zs ! occurrence is one of the two reasons the 57 ,9! {5.2! .5! .8! .9! STkTtONS, FT. m! a. End of placement box, Tests l and 2. Also see Figure 47.! { > 4! >.7! -0! . 3! .8! STkTIGNS, FT. rn! b. Side of pl icemen . box, Tests 4 and 5. Also see Figure 48.! Figure 46. Reinforcing steel placement. Plan view.! Stee! u ed was No, 11 bars, Figure 47. Concrete laitance! flow around reinforcing steel, Test l. 59 Ffgure 48. Concrete flow around reinforcing steeI, Teat 5. 60 other being improved workability and flow! patterns, final color distribution, density, traditionally given for increasing the cement flow around reinforcing steel, and Laitance content for tremie placements. formation, The results of these placements show that 4. No single flow mechanism for tremie placed cerient loss/Laitance formation is indeed a concrete was identified. Instead, two basic problem which must be considered. flow patterns were seen, The first of these was horizontally layered while the second was vertically Layered. The latter produced much For the first cwo tears, the material which flatter concrete slopes, pi'ovided better quality reached che far end of the placement was almost concrete at the far end of the placemenc, and entirely laitance. Test 3 did show concrete produced much less laitance, making it the at the end of the box, but there was also a preferred flow pattern for actual placements, significant amount of Laitance. The quality of the concrete near che end of the box in 5. The type of flow mechanism which develops these tests was unsatisfactory for the first appears to be a function of the concrete being two tests and marginal for the third. placed. The tests with the vertically layered flow used concrete containing the second type of The concrete at the far end of the box foi' the water reducer/retarder. Apparently, this admix- last two tests showed s much smaller amount ture reduced the shear resistance of the fresh of laitance - only a few inches, with this concrete allowing the vertically layered type laitance being on top of sound concrete. of flow to take place, The change in the amount of Laitance may be 6. The results of these flow tests lead to the the result of the following: conclusion that determination of the shear re- sistance of a potential tremie concrete mixture 1. The second type of water reducing/retarding is a critical step in the mixture design and admixture may have increased the bond of the evaluation process. Additional effort to develop cesmnt into the concrete. a usable shear test for fresh concrete appears to be justified. 2. The type of flow observed for Tests 4 and 5 may have exposed less of the concrete to 7, The concrete mixtures containing the contacc with che water; and therefore, there pozzolanic replacements performed very well was less opportunity fax' cement to be washed . indicating that the recoszsendacionsof the out. The flow seea in Tests 2 and 3, horizontal small-scale tests Chapter 1! were correct. layers, would have exposed more concrete to washing. 8. These large-scale flow tests have led to a better understanding of the tremie placement When washing out does occur, little of the process. By designing concrete mixtures to cement seems to go inco suspension in the give a particular type of flow, the engineer water. The majority appears to stay near the will have a greater degree of concrol over surface of the concrete and to flow toward the underwater placemencs which should Lead to Low end of the placement. Ia all nf the tests, improved results on future projects, there was a minimal layer /4 to 1/2 in. ,6- l. 3 cm!! of laitance which was deposited over the entire sample by cement precipitating out of suspension after the placement was completed. No difference was detected in laitance forma- tion for the concretes with and without porzo- lan, However, the laitance in Test 2 which contained significant proportions of pozzolan which had washed ouc, was soft and did not set, as did the other accumulations of laitance. ~2.4 4 . T4 411 4 '4 these tests: l. Five concrete mixtures of approximately 6 yd each .6 m ! were placed by tremie under water in a laboratory placement box. The mixtures differed in pozzolaa content and in, the types of admixtures used. 2, The concrete placements were divided into three equal segments which were colored dif fer- ently to allow for later identification of the co~crete. 3. Data were collecced during snd after the concrete placements covering concrete flow 61 CHAPTER3 pier to the south. Pier 12 was constructed using a cofferdam made up of ARBED interlocked TRENTE CONCRETEPLACEMENT, N-piles, Two levels of internal bracing were 1-205 COLUMBIA RIVER BRIDGE used to strengthen the cofferdam. The nominal inside dimensions of the cofferdam wer'e 54 x 140 ft 6. 5 x 42.6 rn!. The base of the seal of the project was to observe tremie concrete was designed to be at a depth of 78 ft placement of a nonstructural seal for a 3.8 m! with the top of the seal at a depth pier of a major bridge. The following azeas of 45 ft 3.7 m!, These nominal dimensions were of particular interest: lead to a volume of concrete required of 9,240 yd ,065 m3!. a. Behavior of a tzemie concrete mixture containing a fly ash replacement of a The actual dimensions of the cofferdam varied portion of the cement; slightly as did the top and bottom r!levations of the seal. A total of 9,750 yd3 ,455 rn ! b. Prediction and measurement of ternpera- of concrete were actually placed by tremie.- tures developed within the seal con- crete; and, 3. 2. 3 Tem erature redictions. Early in the planning process, the State of Oregon and the c. Examination of flow patterns of the contractor raised the question of problems tremie concrete. associated with temperature development in such a large placement. At their request, several analyses were performed using a 3.2 Back round. computer progrmn based upon a one-dimensional heat flow evaluation technique usually 3.2.1 Descri cion of the brid e. This bridge, referred to as the Garison Method after its when completed, will cross the Columbia River. developer, Roy Carlson ref. 24!. east of Por tland, Oregon. The bridge will provide a bypass around the downtown Portland The following assumptions weve made while area for I-5 users as well as carry local com- applying the Carlson Method: muter traffic. a. Heat flow is considered in one direction The total project length is 11,750 fc ,580 only. For the tremie placement of Pier 12, m! ~ Included in this total are major bridges heat low in the vert. ical direction was over the north and south channels of the evaluated. Columbia River and a 1,100 fc 35 e! fill section across an island. The North Channel b. Heat generation within the concrete is crossing is two entirely separate structures adiabatic. which share a common foundation at Piers 12 and 13 only. The South Channel crossing is two c. The adiabatic temperature increase for a separate structures for all of its length. The mix being evaluated is directly proportional South Channel Bridges will be 3,120 ft 951 m! to the adiabatic temperature increase of a long and will be constructed using a cast-in- reference mix whose adiabatic curve is known. place technique. The North Channel Bridges The proportional constant is the cement con- will be constructed using a segmented box gir- tent of the trial mix divided by the cement der technique. These structures will have a content of the reference mix. total length of 7,460 ft ,274 m! with main spans of 480; 600; and 480 ft 46; 183; 146 m!. d. Heat generation for a given amount of When complete, the North Channel scructures posnolanic material is one-half that will be the longest segmented box girder bridges of the same weight of cement. in North America. e. The thermal diffusivity of the concrete and The contractor who was awarded che substructure the underlying rock is 1.00 ft /day .08 x contract foz the North Channel Bridges is a 10 m2/s!. joint venture of Willamette-Western Corp, Alaska Constructors, Inc., and General Con- f. The initiaL temperature of the underlying struction Co. He is using both structural and material is the same as the river' water. nonstructural tremie concrete on the project, Reusable steel forms are being used to cast 26 g. The continuous placement of the tremie may double bell piers incorporating reinforced be modelled by an incremental technique. tremie concrete. Two additional piers are being constructed using cofferdams with tremde- Due to the assumptions noted and to uncertainties placed seals. Except where specifically noted, about the input data for actual materials to be the work covered in chis report deals with used, the results of the predictions were viewed nonstructural tremie-placed concrete seal of as only relative indications of the temperatures Pier 12 of the North Channel Crossing, 3.2.2 Geometr of Pier 12. This pier is the northernmost river pier in the project. The * For more information on the bridge icself and main 600 ft 83 rn! span of the two bridges the construction techniques being used, see will be between Pier 12 and Pier 13, the next references 19 through 23. 62 which would be developed by the various mix- wires which allowed the concrete flow to begin. tures. Thc temperature predictior,s are shown The same sealing techniques were used when a in Tabl.e 15. tremie was moved and restarted. These predictions indicated that high tempera- Three tremies rwo supplied by the floating plant tures cauld be expected in the seal concrete and one supplied from shore! were normally in use and that replaCen:ent of a portion of the cerreer. at one time. Placement was started with all three would be Lhe most feasible way of meeting the rremies along the short centerline of the coffer- State 's desize for a 140 F 0 C! maximum dam. As the seal in this area was brought up to ten'perature. grade, rhe tremies were movedtoward the ends of the cofferdam, The locations for restarting a The desire to reduce temperaruze in the seal tremie were established by soundings, concrete was heightened by surface cracking of a large pier shaft on shore which occurred at 3,3 Observations and Discussian about the time the calculations were being dane. This cracking was attributed to thermal 3.3.1 Heasured tern eratures. The temperatures gradient problems. which developed in the tremie concrete were mea- sured using 34 resistance thermometers placed in It must be stressed that one of the most the northeast quadrant of the cofferdam. These significant assumptionsoi' the Carlson Hethcd insrruments were Located at various elevations in is that heat flux occurs only in the verticaI four planes Rows1-4! perpendicular to rhe long direction. Thus, I he predictions above are axis of the cofferdam as is shown in Figure 54. valid only far the center of I he concrete mass. Exacr. instrument locations are given in Appendix 8, For those areas near the edges of the seal, where patentia11y significant temperature Readings were mademanually using a variable gradients may develop, another technique must resistance box nominally every Lwo hours for the be used. To overcome this problem, a program first 80 hours after tbe placement began Figure was writLen to allow use of an existing finite- 55!, Readings were then taken two or three times element program for prediction of temperatures daily for an additional 13 days until the contractor in I.remie concrete as is described rn Chapter began pzepar ing r.a place thc next lift of concrete 5, for the pier, Temperaturedata, a description of the data recording technique, and data reduction 3,2,4 Tremie concrete mixture. Based upon the methods are given in Appendix I. The data ob- predictions above, the concrete Inixture des- tained are d iscussed be low: cribed in Table 16 was selected for use. This mixture was developed as is our 1 ined in the a. Haximumtempera I.ores. Tl e maximumtenIpera- table. As is also shown in Tabl» 16, this ture recorded for each instrument and a brie f mixture has an equivalent cement content for descipt ion of instrument locarions are given in heaL. generation purposes of 611 lb/yd 6! Table 17. Rote that the river temperature during kg/m3!. and following placementwas approximately 55a F 13oC!. The concrete placement temperature rang- e 3.2.5 Placement techni ue. Tremie concrete ed from 60 to 65 F 6 to 18 C!. The maximum placement for Pier 12 began at 8 A.H. on 15 Hay concrete temperar.ure recorded therefore repre- 1978, and was essentially continuous for 72 sents a 90 to 95 F 2 to 35a C! increase. hours. The majority of the concrete was barched in a floating plant moored at the site. Two The remperatures recorded for instruments 5, 7, pumps were used to transfer concrete from the and 9 are less than antic ipated. These instru- plant ta the tremies. Additional concrete was ments mayhave ma1 functionedor the law readings barched at a nearby zcady~ix plant and was may have been causedby a zone of incernented trucked ro rhe site. This concrete was pumped material descr ibed below in section 3. 3.4 !. aloof a causeway leading from shore to the cof ferdarn, Figures 49 and 50 show the sire and A summary of temperatures based upon instrument thr cofferdam during the placement pz'ocess. groupings is given in Table 18. As anticipated, the maximumtemperatures developed in the center The tremies were manufactured fram 10 in. 5.4 of the concrete mass. cm! pipe. Connections were Elanged and gasket- ed. A hopper was bolted onto the top of each The temperatures which developed near the out- tremie and each tremie had its own frame and side edges of the seal and near the top surface air hoist to al low for vertical movement. The represent potentially significant thermal gra- upper portions of the tremies were Inadeup of 5 dients as is discussed below, The range of ft l. 5 m! sections which allowed for removal temperatures in the group of instruments near of sections as the placement progressed. Details the top surface of the seal maybe attributed of the tremies and the support frames are shown to the varying depths of concrete cover which in Figures 51 and 52. were actually achieved. The tremies were started dry with the lower end b. Temperaturehistories, The locations of sealed with a metal plate and rubber gasket four representat ive instruments are shownin Figure 53!. The plate was wired onto the end Figure 56. Time versus temperature curves foz of the tremie. The concrere used ta fi 1 1 the these instruments are presented in Figures 57 the tremies initially was therefore dropped through 60. approximately 80 ft 4.4 m!. Once full of concrete, the tremies were lifted breaking the 63 TABLE 15 TEMPERATURES PREDICTED USING THE CARLSONMETHOD NOTES; ! Predicted temperatures at 10 days after beginning of placement. ! All predictions assume river water temperatures of 45 F 'C! . Figure 49. Overall view of site during placement of tremie concrete for Pier 12 of I-205 Bridge. 64 TABLE 16 TREHIE COHCRETEHIXTURK, PIER 12, I-205 BRIDGE This mixture was developed as follows: 3' 3 3 Cement: 7 sacks/yd ~ 658 lb /yd 90 kg/m ! Less 20 percent -132 78 ! 3 3 Net 526 lb /yd 12 kg/m' ! 3 3 Fly Ash: 125 percent of cement. 165 Ib /yd 98 kg/m ! re duct ion Figure 50. View inside cofferdam during tremie concrete placement. 65 Details of tremie placement equipment frame supporting hopper and pipe. Note air hoist which allowed vertical movement of pipe during placement. 66 Figure 52. Tremie system being moved to new location. Note flanged connections on upper portion of the tr ernie pipe. 67 Figure 53. Steel end plate and rubber washer being tied to end of tremie pipe to seal pipe during a change of tremie location. 68 INTERLOCKED H- PILES PIPE STRUTS INTERIOR BRACE RING ~ INDICATES A VERTICAL OIX U LINE OF INSTRUMENTS 4J 0 03 IN STRUMENT ROW I O O IN ST RUMENT ROW 2 IN STRUMENT ROW 3 INSTRUMENT ROW 4 NOMINAL 54 x 140ft, I6,5 x 42.7 m! INSIDE SHEET PILES Figure 54. General instrumentation plan, Pier 12, I-205 Bridge. 69 Figure 55. Manual recording of temperatures in seal concrete. Note interlocked ARBED H-pile system. 70 TABLE17 MA!HMDMTEMPERATURES RECORDED IH PIER 12 SEALCONCRETE Nax Elapsed Temp ac Temp at 386 Mrs, 29 Days, Inst. Instrument Location Temp, Time, OF oc! F 'C! Mo. Horisontally Ver t x ca 1 ly OF oc> Hrs. Nid-Depth of Water in 4! 140 57 4! Cofferdam Water, 1 Fc Above 58 4! 340 4! Design Seal Surface 3* C-L Top oZ Seel 57 4! 140 57 4! 4 C-L Top of Seal 110 3! 1LO 92 3! »ee C-L Mid depth 129 4> 180 129 4! 6 C-L Bottom 122 0! 130 119 8! MA 74* Off C-L Top Qtr Pt 95 5! 250 79 6! MA 150 6! 8 Off C-L Bottom Qtr Pt 155 8! 310 155 8! 9** Off C-L Mid-depth 116 7! 220 106 1! 10 Outa ide Edge Top of Seal 82 8! 90 60 6! 11 Out s ide Edge Top of Seal 107 2! 100 61 6! HA 12 Outside Edge Mid-depth 92 3! 66 74 3! 13 Outside Edge Bottom 94 4> 24 81 7! Instrument Lost 14 Water Outside Cofferdam 15 C L Top of Seal 90 2! 120 82 8! 78 6! 16 C-L Mid-depth 150 6! 380 150 6> 154 8! 17 C-L Bottom 119 - 8! 150 117 7> 111 4! 18 Outside Edge Top of Seal 121 9! 130 93 4! 19 Outside Edge Mid-depth 105 1! 210 81 7! 20 Outside Edge Bottom 101 8> 50 84 9! 21 C-L Top of Seal 114 6> 140 101 8! llA 22 C-L Top of Seal 139 9! 180 130 4! 148 <64> 23 C-L Mid depth 154 8! 370 154 8! 24 C-L Bottom 118 <48> 180 116 7! HA 25 Outs ide Edge Top of Seal 108 2! 140 86 0! 7» 4> 26 Out s ide Edge Top of Seal 127 <53> 170 105 1! 87 1> 27 Outs ide Edge Mid depth 125 2! 180 109 3! 96 6> 28 Outside Edge Bottom 102 9! 100 78 6! 67 9! 29 C-L Top of seal 94 4! 130 70 1! 30 C-L Nid-depth 142 1! 170 121 95 31 C-L Bottom 100 8! 70 90 2! 32 Outside Edge Top of Seal 116 7! 140 90 2! 33 Outside Edge Mid depth 143 2! 150 112 4! 34 Outside Edge Bottom 87 1! 22 64 8! elnstrumenc located in water, not in concrete. Instrument 3 was not embedded in concrete as planned. ** Readings for chese instruments appear to be questionable. See text. 71 TABLE 18 MAXIMDM TEMPERATURES GROUPED BY INSTRHMI3NT LOCATION Instruments and Te eratures op At or near center-line of pier, ¹ 5* 129 4! mid-depth of seal. ¹ 7» 95 5! Excluding Row 4! ¹. 8 155 8! 9e 116 7! ¹16 150 6! ¹23 154 8! At or near center-line of pier, ¹ 6 122 0! bottom of seal ¹17 119 8! Excluding Row 4! ¹24 118 8! Outside edge of cofferdam, ¹12 92 3! mid-depth of seal ¹19 105 1! ¹30 142 1! ¹33 143 2! Outside edge of cofferdam, ¹13 94 4! bottom of seal ¹20 101 8! ¹28 102 9! 100 8! 87 »! Near top surface, all locations ¹ 4 110 3! ¹10 82 8! ¹15 90 2! ¹18 121 9! ¹21 114 6! ¹25 108 2! ¹29 94 4! ¹32 116 7! NOTE: *Readings for these instruments appear to be questionable. See texts 72 73 160 1.1 140 0.0 D e 120 1. 8.9 0; X IOP 7.8 LU LLI 8O Z 67 8 IM! 50 lo,o!p 50 lpo 150 200 250 300 350 400 TIME SINGE BEGINNING OF PLACEMENT, HRS. Ff.gure $7. Temperature history, Xnst. Ho. 8, near centerline, mid-depth of eeai. 160 1.1! 140 0.0! C3 0 120 8.9! 0 IOO 7.8! I- LU u 80 O~ <7! O 5.8! 50 Iao!o 50 100 150 200 250 300 350 400 TIME SINGE BEGINNINGOF PLACEMENT, HRS. Figure 58. Temperature ldstory, Inst. No. 11, outside edge, top of seal. 74 I60 I.I ! I40 ao! P I 20 I 8.8! R: X IOO 7,8! O 80 Z 6.7! 8 I5.6! 50 IO,O 50 l00 l50 200 250 300 TIME SINCE BEGINNING OF PLACEMENT, HRS. Figure 59. Temperature history, lost, Ilo. 24, ceaterline, bottcna of seal. I 60 I.I! l40 0.0! 4 I20 I, 8.9! Ipo 7.8! 8.7! 8 60 IL6! IIM!p 50 l00 l50 R00 R50 300 TIME NNCE BEGINNINGOF PLACEMENT, HAS. Figure 60. Teaperature history, lest. Ho. 29, caaterliae, top of seal. 75 Readings for several instruments were taken on be calculated using the following equationr* 13 June 1978, 29 days afcer placement began. These temperatures are also shown in Table 17, E crAT! R A sunnnary of temperatures 386 hours after placement began the end of regular readings! is as follows: where cr 5 .5 x 10 6in. /in. / P AT 1.5o F/in, x 40 in. = 60op 60-85oF 6-29oC! Ll instruments R 1.0 for complete constrainc exterior locations! For K x 106 lb/in 2 Aa = 330 lb/j,n 2 For 8 3,0 x 10 lb/in.2 Aa 990 lb/in. 86-105aP 0-41oC! 7 instr uments tap of seal Locations! Further, assume a rate of temperature develop- ment of 0.4 F/hr ,22 C/hr!. For the total 106-125 F 2-52oC! 1 instruments differential of 60 F 3oC!, the stress calcu- various locations! lated above would be developed in 150 hours. 126-155 F 3-68 C! 5 instruments Since the exact properties of the concrete at interior locations! early ages are unknown, it is impossible to say with certainty what effects the stresses Thus, after 386 hours, the interior of the calculated above would have on the seal. It concrete remained very close to its maximum appears that these stresses are large enough temperature while the edges and surfaces were and develop rapidly enough to be of concern. showing significant cooling. 3.3.2 Measured versus redicted tern etatures, c. Gradients. The data for those instruments After the placement was complete, the Carlson near the edge or near the top of the seal were Method program described above was used to examined co determine the temper'ature gradients predict temperatures within the seal based which developed in the extreme, portions of the upon the actual placement conditions mixture concrete. The outside surface of the concrete design, water temperature and concrete ternpera- was assumed to be at the water temperature, ture!; The temperatures predicted by this 55 F 3 C!. Table 19 summarizes these gra- run were compared with the measured temperatures dients by instrument Location, The data in to determine the reliability of the prediction this table point out the following: technique. Overall, the prediction technique was accurate to within approximately ten 1. Large temperature differentials developed percent of measured values when considering in the outside portions of the concrete a locations near the center of the concrete maximum dif ference of 88 F 1 C! above the mass. A sunnnary of predicted versus measured river temperature was recorded. temperatures for various elevations within the seal is given in Table 20 Camparisons 2. When the distances of the instruments from of the various instrument groups are given the face of the concrete are taken into account below. Tables of predicted versus measured to develop a gradient in terms of temperature temperacures are given in Appendix J. change per unit length, the various instruments may be compared. The gradients for the mid- A. Hid&epth instrumencs. The maximumtempera- depth and top instruments, taken to the outside ture predicted at the end of 10 days after of che seal, are both approximately L.5 F/in. the beginning of placement was 144 P 2 C! .4 C/cm!. For the top instruments taken at a station appraximately 13 Et rn! above toward the top surface, the gradients were more the base of che seal, From about 7 ft m! varied and ranged up to 4.4 F/in. L,O C/cm!. to 28 ft 9 m! above the base of the seal, the predicted temperature was slightly above 3. The rate of gradient development was gen- 140 F 0oC!, A comparison af the midMepth erally consistent at 0.4oF/hr .2 C/hr! when instruments along or near' the center line of the bottom instruments are excluded. The the seal at the end of 10 days shows: bottom instruments developed their maximum values at a faster rate since the underlying material Inst. No. 5: 129 P 4o C! was not as efficient a heat sink as the river Inst. Na. 7; 92oF 3o C water. Inst. No. 8: 153aP 7o C! Inst. Na. 16: 145 F 3a C! d. Temperature induced stress. A derailed exam- Inst, No. 23, 150oF 6o C ination of temperature induced stress is beyond the scope of this report. However, che following The readings for instruments 5 and 7 are not calculations are presenced based upon typical consistent with similarly placed instruments, gradients described above to point out the sig- nificance of the temperatures which were develop- ed in the seal concrete. Ar7 - E aAT!R Consider a mid-depth location 40 in. m! from Where m = 2.5 x 10 5 cm/cm/o G the outside of the seal typical temperature AT = 0.33 C/cm x 102 cm ~ 34 C instrument location! at which the gradient is R 1.0 for complete constraint 1.5oF/in. .33 C/cm!. Assuming complete con- For E ~ 6895 Mpa, Ao' ~ 2.3 NPa straint and neglecting creep the approximate E - 20685 MPa,ha = 6.9 Npa change. in scress across the concrete section may 76 ThSLE 19- TEMPERATUREGRN!IENTS XN OUTERPORTIONS OF SEhLCONCRETE 77 TABLE 20 PREDICTED VERSUS MEASUREDTEMPERATURES AT VARIOUS ELEVATIONS, 240 HOURSAFTER BEGINNING OF PLACEMENT Elevation Above Measured Temperature Bottom of Predicted Inst ¹/oF oC! Seal, Ft, Temp oF Multiple inst at same m! oC! elevation are on same line! 35 0.7! 55 3! 34 71 zz! ¹3/56 <13!; ¹15/86 0! 32 110 3! ¹4/101 8!; ¹21/108 2! 39 9.1! 127 3! ¹22/137 8! 28 138 9! 26 142 1! ¹7~/92 3! 24 .3! 143 2! 22 143 z! 20 143 2! ¹16/145 3! 18 .5! 143 2! ¹5*/129 4!> ¹9*/116 7!; ¹23/150 6! 16 143 2! 14 144 2! 12 .7! 144 2! 10 143 2! ¹8/153 7! 8 141 1! 6 .8! 137 8! 4 130 4! 2 118 8! 1 103 9! ¹6/122 0!; ¹17/119 8!; ¹24/118 8! 0 <0! 100 8! *Readingsfor theseinstruments appear to bequestionable. See text. TABLE 21 SUMMARYOF CONCRETEPRODUCTION FOR PIER 12 3 3 Production, yd m ! Time, Total hours Land Floatine Plant Plant 0 - 10 477 365! 1>074 821! 1,551 ,186! 10 20 450 344! 984 752! 1,434 .096! 20 - 30 405 310! 990 757! 1,395 ,067! 30 40 482 369! 558 427! 1,040 796! 40 50 578 442! 636 486! 1,214 928! 50 60 544 416! 1,194 913! 1,73e ,329! 60 72 528 < 404! 834 638! 1,362 >042! 3,464 ,648! 6,270 ,794! 9,734 ,442! *NOTE'-Totals for SI unitsdiffer dueto rounding. 7B The remainder of the instruments are in good concrete production and placement, this data agreementwith the predictions, with the pre- may be viewed as essentially a record of concrete dictions being about 10oF .5oC! below measured placement.The total productionwss 9,734 yd3 values. ,442 m ! vith an average of 13S yd /hr 03 m3/hr! for the 72 hr placement period. This b. Bottom instruments. A comparison of three rate agrees veil with that assumed for the instruments shoved very good agreement vith temperaturepredictions of 150yd 3 /hr3 15 m / predicted values. The maximumpredicted temper- hr!. ature vas 110 F 3 C! at a station approxi- mately 1 ft .3 m! above the base of the seal. Production shoved the most noticeable drop measured temperastures vere as follows: during the 30 ta 40 hour period due ta diffi- culties of resupplying cement ta the floating Inst Ho. 6' .123 F 1 C! batch plant. This slowdown can be seen in Inst Ha 17: 119 F 8 C! the cross-sections presented below. Inst No. 24: 119o F 8a C! For the first 21.S hrs while the tremies vere Again, the predictions are below tha measured along the short centerline of the cof ferdam, values by about the samedifference as for the the production rate translated into an average mid-depth instruments. concrete rate of rise of 0.8 fr/hr 4 cm/hr! adjacent to the tremies and 0.4 ft/hr 2 c. Tap instruments. A comparison of four instru- cm/hr! at the far ends of the seal. These ments near the top of the seal also showed very rates are both well below recommended rates good agreement with predicted values, Due to found in the literature refs. 1, 4, and 15!. the variable cover which was achieved over the instruments, the comparisons below are given in b. Concrete flow distance. Concrete was de- ranges of temperarures representing the top 5 tected both by temperature and by soundings at ft .5 m! of the seal. the ends of the cofferdam within about 5 hrs Time after after 'placement began. This concrete vas placement Predicted Heasured flowing in excess of 70 ft 1 m!, again higher sterted temperatures temperatures than normally recommendedlimits refs. 1 and oF oC OF OC 4!. 5.0 days 80-120 7-49! 90-125 2-52! c. Placement cross-sections. Figures 61 through 10.0 days 71-132 2-56! 86-138 0-59! 64 shov cross-sections of the seal during the placement for four different locations. The As above, the measured values were above the var iations in production noted above are apparent predicted values by about the same difference. in these figures. Two items are of special interest in these figures,' d. Edge instruments. As noted earlier, the Carlson Hethod assumes heat flow in one direc- 1. Temperature instiument locations vere plotted tion only. For those instruments near the out- on Figure 63 in an attempt to explain the law side edges of the seal where significant lateral readings for instruments 5, 7, and 9. The fig- heat flov could be expected, the measured temper- ure does not indicate any abnormality in the atures were weLL beLow predicted values. How- rate at which these instruments were embedded in ever, two instruments, 30 and 33, both located at the concrete. mid-depth at the end of the cofferdam, developed maximumtemperastures higher than anticipated 2. The location marked * ! in Figures 6 1 and for their outside positions. Both instruments 63 indicates an area in vhich a major zone of did show significant temperature decreases by uncemented material was found after the place- 380 hours shoving the influence of the outside ment was completed. The placement rate at locations, The extra concrete thickness be- this location appears to be higher than average, tween these instruments and the cofferdam wall but would not normally draw attention during when compared to other edge instruments! may the placement. The unusually steep slope of account for the higher temperatures vhich the concrete at the 30 hour line of Figure 63 developed. may have contributed to the formation of the poor quality zone by trapping laitance. 3 . 3. 3 Conci'ete flow atterns . Soundings wei e taken by State inspectors throughout the place- c. Concrete slopes. The sounding data was ment period to monitor progress and to provide used to determine the surface slope of the data for examining, the flow of the tremie con- tremie concrete during and after completion of crete. After the placement, the soundings vere the placement. The paints made below may also also correlated with temperature readings in, an be seen on Figures 61 through 64. attempt to discover why measured temperatures were not as high as anticipated far instruments l. The slope of the concrete parallel ta the 5, 7, and 9. The following items are based short axis of the cofferdam was much flatter upon this sounding data and upon concrete pro- than that in the long direction. This short duction data. axis slope had an average value af 1:23 along, the centerline and 1:47 at the ends of the a. Concrete production rare. Table 21 shows cofferdam. These flat slopes probably result- concrete production data for the placement per- ed from the close lateral spacing of the tre- iod. Since there vas little delay between mies. While all three tremies were along the 79 PLAN! -40 2.2! -50 5. 2! C u. -60 8,3! I LLI -70 1.3! -80 4.4!DOWNSTREAM VPSTREAM Figure 61, Tremie concrete profiles at various times after beginning of placement, long axis of seal, adjacent to north side of cofferdam, PLAN! -40 2.2! -50 5.2! 8 I- -80 Z 8.3! I- uI -70 1. 31 -80 4.4! Figure 62. Tremie concrete profiles st various times after beginning of placement, long axis of seal, north of center line. 80 -40 IR,2! PLAN! -50 5.2! C I- ~ -60 O 8.3! I- cC -70 1,3! -80 R4.4! Figure 63, Tremieconcrete profiles at various times after beginning of placement, short axis of seal, along centerline. -40 I 2.2! PLAH! -50 5,2! 6 b. ~ -60 I 6,3! O I UI 70 Rl.g! -ep 4.4! Figure 64. Tremie concrete profiles at various times after beginning of placement, short axis of seal, upstream end of cofferdam. 81 short cenCerline approximately the first 21.5 seams of permeable material is probably pre- hours!, the spacing was less than 20 ft m! sent. The flov may a1so be partially attribu- from tremie to Cremie. table to any cracking which was caused by the thermal gradients which were developed. Figure 2. The slope along the long axis vas usually 69 sho~s this water flow from one core hole. greater than that described above. It ranged from an average of 1;6 for the zone nearest One of the investigators mentioned in the the tremies to an average of 1:10 for the Introduction, Lavrence Livermore Laboratory, areas closest ta the ends of the cofferdam. reported an anamoly in their readings in the southwest quadrant of the cofferdam. 3. The slopes based upon soundings taken after Core ¹5 Figure 67! vas drilled to determine the placement vas completed vary considerably che validiry of the reading,s. This core turn- between sounding points approximacely 18 fc ed out to be sound «ith no bad material found .5 m! apart! ranging from 1:7 to flat. In at any depth. general, the soundings shoved that a reason- ably flat surface was obtained. c. Najor void. A major void area vas dis- covered on the north side of the seal in the 3.3.4 Concrete ualit . One author Holland ! vicinity of Che intersection Of the noth edge vistied the site once the cofferdam was de- and the short centerline. This area has been watered and inspected the concrete. The follov- mentioned earlier and is shawn on Figures 61 ing is based upon his observations, Cheresults and 63. The void consisted of sn area of un- of core sampling, and observations af the Pro- cementedaggregates. No explanation for the ject Engineer. origin of this void area is readily available. This void was actually Cwo distinct areas. a. Visual inspection. The concrete which was The first began about 4 ft .2 m! below che visible not under water in low areas! was tap of the seal and was 12 to 18 in. 0 to 46 sound and a minimum of laitance was present. cm! thick. This area extended 10 to 12 ft The surface concrete which was tested with a to 3.7 m! in the long direction of the seal heavy steel px'obewas resistant to penetration. and vas xeported as reaching about 20 in. 1 No cracking was visible on the surface. cm! into the seal from the edge by a diver. One noticeable problem was very evident, how- The second area began 8 to 10 ft .4 to 3 m! ever. The surface of Che concrete was extreme- belo~ the top of the seal and was approximately ly uneven-- muchmore so chan was anticipated 3 fc m! thick. The diver could measure a from the soundingswhich showed a maximumdif- length of 15 ft , 6 m! snd estimated a total ferential between adjacent soundings of 2.6 ft length of 20 to 25 ft ,1 to 7.6 m!, This area O,B m!. A number of mounds 3 to 4 ft .9 co extended at least 6 ft .8 m! into the seaL 1.2 m! tall were present as vere several lov from the outside edge. areas. The maximum differential betveen the mounds snd low areas was approximately 4 to 6 fc. The lack of cemented xsaterial in the lower .2 co 1.8 m!. The mounds were located at the void is pxobsbly the cause of the low readings positions of the cremie pipes near the end of of instruments 7 and 9 and possibly instrutsent the placement when attempts were being made to 5. No hydration was occurring and there vas bring the top of the seal to grade. See Figures apparently water present to help carry heat to 65 and 66. the outside of the cofferdam. Both of these factors could have contributed to the low The mounding problem probably resulted from reading s. the typically low volumes of concrete placed through the tremies at the end of the place- d. Diver inspection. In addition to examining ment and the steep slopes being achieved near the voids described above, a diver inspected the tremie pipes. Not enough concrete vas the vertical surfaces of the seal concrete being placed to overcome flaw resistance and after the piling vas pulled. Na cracks were flatten out the slopes. found, but this does not necessarily rule out cracking caused by thermal expansion since the The mounds forced the contracCox to remove inspection was conducted under conditions of concrete to allow for correct positioning of poor visibility. Also, the subsequentcooling reinforcing steel for the next lift of con- of the concrete mass could have closed early crete. cracks. b. Cores, Initially, four cores were drilled ~3I S . Yh f ll '~ 't into the seal as is shown in Figure this placement: 67. When inspected, these cores vere very good and shoved virtually no bad concrete. 1, A total of 9,734yd ,442 m3! of concrete Two cores, ¹4 and ¹1., shoved several inches of were placed by tremie for a nonstructural seal possibly trapped liatsnce Figure 68!. for Pier 12 of the 1-205 Columbia River Bridge. The placement vas continuous for 72 hours with Water vas flowing from all core holes, with an averageconcrete placement rate of 135yd3/hr the greatest flow coming from bole ¹2, which 102 m 3/hr! . went all the way through the seal. Since there vas flow from the other cores which did not go thxough the seal, a system of small 82 Figure 65. Mounding on surface of seal. This mound was located at one of the final tremie locations. Figure 66, Low area in surface of seal. This photo was taken during preparation of the next lift of concrete. 83 20,0f ff. m! O Q' K 03 OFigure67.ofCore interlockedlocations, piles.Pier12, Dimensions toinside 84 Figure 68. Section of core taken from tremie concrete. Note the area at the 23 f t .0 m! mark. This small zone of laitance was the worst concrete seen on the four cores. Figure 69. Water flowing from core hole in tremie seal. B5 2. The concrete mixCure used included fly ash as approximately 24 percent by weight of the cementitious material. The fly ash was in- cluded to reduce the heat generated by the hydration process. This is, as far as is known, the first. major underwater placement to include fly ash for thc purpose of reducing heat. 3, Temperature prcd ict ions raade for the sca I concrete using the Garison one-dimensional prediction technique proved Co be accurate to withirr 10 percent of measured values. The pre- dictions were, in this case, on the low side of the measured temperatures. The predictions were accurate for. the entire vertical sec Lion of the seal at those locations where lateral heat flow co the outside of che mass could be neglected. 4. A maximum temperature of 155 F S C! deve]oped in the center of the concrete mass. Concrete temperatures developed as expected for various instruraent locaCions with the exception of one zone of low temperature which is believed to have been caused by an area later found to be largely uncemented aggregate. 5. Steep temperature gradienCs developed across relatively thin concrete sections between outer- most ceraperature instruments and the exterior of the seal. These gradients developed rapid ly and may have been high enough co generate stresses large enough to cause cracking in the concrete with consequent water entry into the mass. 6. Tremie concrete flowed a maximum distance of ovr'r 70 f t J m! wi thnut apparent de tr imenra1 effects, Cores taken near che extremes of the flow revealed sound concrete. Cross sections and calculacions based on soundings showed rather steep slopes in the direction of flow nearest the tremies, 1:6, while near the ends of the cofferdam the slope had I'let tened to 1: 10. 7, The concrete produced was generally very sound and capable of pcr forming its intended function, Localized mounding necessitated extra work for the conCractor in preparing for the next li fr of concrete for the pier. Two areas of uncemented aggregates were found within the seal which required grouting. g, Inspection of che seal concrete upper surface after dewaterinp revealed no cracking. Inspec- tion of the vertical concrete surfaces by a diver after removal of the cofferdam piling also failed to reveal evidence of cracking. 9. Water flow was observed from core holes including hales which did not penetrate the fu11 thickness of the seal. Thin seams of permeable material or cracks caused by therm- ally induced ~tress or a combination of both are postulated as the source of the flows. 86 CHAPTER4 After extensive site investigations, the Corps TRENIE COHCRETECUTOFF WALL, of Engineers and its consultants theorized WOLFCREEK DAW that the flow was either through the original cutoff trench or through a combination of the cutof f trench and a series of solution featui'es. of the project was to observe and reviev place- It should be noted that Che original cutoff ment of tremie concrete during construction of trench is only about 10 ft m! wide at its a cutoff wail through an existing earthfill narrowest point, Photographs indicate that the dam. Three areas were of particular interest: rock in the veils of the trench is fractured and jointed and in many cases the walls are a. Behavior of a tremie concrete mixture con- verCical oi even overhang the excavated portion.! taining a fly ash replacemenC of a portion of The repair procedure recommended was to construct the cement; a positive cutoff wall through the earthfill portion reaching into sound rock belov the b. Placement of tremie concrete at extreme dam. Additionally, a cutoff wall vas to be depths; and constructed to isolate the switchyard area. c, Identification of problems in mixture design 4.2.3 Re air rocedures. The construction or placement technique which resulted in rones procedure selecCed to install the cutoff walls of poor quality concrete, was modification of the slurry vail procedure often used on foundation excavations.» The embankment cutoff vali is 2240 ft 83 m! long and has a maximumdepth of 280 ft 85 m!. 4.2,1 Descri tion of the dam.» Wolf Creek Dam Due to concern over the stability is a multi-purpose structure pover generation, of the dam during construction, the wall vas flood control, recreation! located on Che constructed of alternating primary cased, 26 Cumberland River near Jamestovn, KY. It lies in. 6 cm! diameter on 4.5 ft 37 cm! centers! in nr area of karst topography approximately and secondary uncased! elements rather than sixty miles 97 km! from I ammoth Cave. Lake of panels as is frequenC iy done on slurry wall Cumberland, impounded by the dam, is the largest foundation projects. Figure 70 shows a sche- manmade lake east of the !Iississippi River. matic of these elements. Construction of the dam was begun in 1941, but A total of 1256 elements were placed to con- woik was discontinued for three years during struct. both of the veils for a total contract World War II. The work accomplished prior to cost of $96.4 million. These elements vere the wai was mainly site preparation and con- broken dovn as follows: struction of the cutoff trench under the earth- fill portion of the dam. The project was Over 250 ft 6 m! deep: 158 completed for full beneficial use in 1952. 200 to 250 ft 1 to 76 m! deep: 666 150 to 200 ft 6 to 61 m! deep: 168 The darn consists of an eai'thf ill section 3940 90 to 150 ft 7 to 46 m! deep: 174 ft 20! m! long and a concrete gravity section less than 90 ft 7 m! deep: 90 1796 ft 47 m! iong. The maximum height of the embankment section is 258 ft 9 m!. The The contractor avarded the project, ICOS Cor- concrete section includes a gated spillway vith poration of America, is a pioneer in the field ten radial gates having a rated discharge of of slurry walk consCruction. Following is a 553,000 ft3/sec 5,660 m3/s!. The power plant step-by-step description of the procedure used has an installed capacity of 270,000 kw in six for the embankment wail.»» units. a. Site Preparation. Since Che crest vidth of 4.2.2 Descri tion of roblem. In October, the dam is only 32 ft 0 m!, the contractor 1967, a muddy flov appeared in the tailrace of constructed a work platfoi'm 170 ft ' 2 m! vide the dam. In Harch ~ 1968, a sink hole appeared inside parallel walls of sheet piling. Actual on the toe of the dam near the switchyard. An excavation took place in a concrete lined investigation of this hole shoved it was con- starter trench which vas constructed along the nected to a solution cavity, In April, 1968, a axis of the wall. Much of the excavation and second sink hole appeared near the first. Dye casing handling equipment was especially de- placed in this hole appeared in the tailrace signed by the contractor foi rhis project where the muddy flow had originally been seen. Figure 71!. As a result of these occurrences, an emergency grout ing program vas under taken. This program resulted in placementof 260,000f t 7,360m3! of grout but provided no assurance of completely *For a general description of the slurry wall resoi.ving the problems. technique see references 31 and 32. »»Since the switchyaid vail vas much sha!lover and since no problems were encountered during ita construction, the remainder of the chapter *For additional descriptions of this project deals only with the embankment wall. see references 25, 26, 27, 28, 29, and 30. 87 W 0 4J 0 8 CJ r5 I 0 I Q ~ gA e 8 v I I W Q~ V l 4J 1 S V Vl Figure 71, Casing handling machine which rotates casing and applies vertical. force for casing installation or removal. Figure 72. Breather tube in tremie hopper. The tube extends to the top of the hopper and allows air to escape during placement. b, Pt imary elements. Initially, a 53 in. 35 The secondary elements, once socketed into sound cm! diameter hole was excavated with a clam rock, were then filled with tremie concrete to shell to a depth of approximately 76 ft 3 m!. displace the slurry. At that point a 47 in. 19 cm! diameter casing was inserted and excavation was continued inside 4.3 Observations and discussion, The following the ~asing, Additional sections of casing were comments are based upon site visits be Ben C. added as necessary vich especially designed Gerwick, Jr., and T. C. Halland, and upon corre- joincs which were flush inside and outside! spondence with the Resident Engineer at the site. until the casing reached down 142 ft 3 m!. Ftom chere to the top of the rock, a 41 in. 4. 3.1 alit of cremie concrete. One item in 04 cm! diameter casing was used. Excavation the consLruction proceduze which is not mentioned below the 76 ft 3 m! poinr was done through abave is the extensive drilling of cores which bentonite slurry, was done approximately cen percent of the elements were cored, This caring program re- When rock was reached, a rock dri 1 1 was used t.o vealed minor but consisCent problems in the quality dz ill a 36 in. 91 cm! d iarneter hale co the of the concret:e in the primary elements. These planned bottom of the wall. Then, a NX core problems included minor areas of segregated sand hole was taken 25 ft 8 rn! deeper into Che and/or coarse aggregate, zones of trapped lsitance, rock. This hole vas pressure tested and, if snd zones of lightly to extremely honeycombed sar isfactory, filled with grout, If the rock concrete. These bad areas are scattered vertically f~iled the pressure test, the 36 in. 91 cm! in the cores and do nat appear to follow a dis- diameter hole was continued deeper. cernable pattern. Figure 75 shows a portion of a core from one elemenC showing the variations in Once che hole was founded in saund rock, the 26 concrete qualiLy, in, 6 cm! diameter permanent casing vas pl.aced. This casing was filled with water to Multiple borings taken in the same element have keep it in place, After the permanent casing shown chat the zones af poor quality concrete vary was in place, the annular space between the horizontally as well as vertically. For example, permanent and excavation casings was filled in element P-465 the first boring showed a 41. 5 ft with grout as the 41 and 47 in. 04 and 119 2.6 m! loss of cote, A secand baring shaved cm! diameter casings were removed. The annular vas made which showed good concrete for its full space grout was allowed to set 10 days before depth. an element was filled with tremie concrete. Ic is important to note that these problems have To begin the filling process, enough bentonite been found in the pzimary elements only. Those slur ry was placed into the casing ca disp!ace anomalies which have shown up in the cores of the Lhe lower 20 EL m! of water. The purpOSe of secondary elements have been explained by such this benLanite was co lubricate the inside factors as loss of drill vertically causing cores walls of the casing during concrete placement. ta cuc into the annular grout near the primary Concrete was bacched and mixed at a plant near elements or by drilling into a stepped portion the dam and transported to the cremie site by of the foundation rock causing loss of a portion trucks, Two unusual items concerning Che of the core. Professional staff at the site are ttemie placement are worthy of noting here. satisfied that all anomalies which have appear'ed First, the tremie hopper was equipped with a in the cores of the secondary elements can be breaching tube vhich allowed ait to escape explained. However, as will be shown below, there during concreting Figure 72! . Almost no air are noc as readily available explanatians for che van seen bubbling to the surface as is common problems discovered in the primary elements. an most tremie placemencs. Second, the con- tractor developed a novel technique for support- 4.3. 2 Tremie starcin rocedures. One of the ing the Czernie pipe. Figure 73 shows how this areas suspected of contributing to the concrete technique ~orked. problems was the procedure used initially to seal the tremie pipe. The placements were begun with c. Secondary Elements. Construction of a the tremie pipe full of water, secondary element followed cornplet ian of two ad jacent primary elements. The overall can- Initially, a rubber basketball vas used as sttuction sequence vas planned to allav an ugo-devilu to start the tremie placements. The adequate curing period for the concrete in the ba11, initially floating inside the tremie, was primary elements before work was started on the forced down the pipe as concrete was introduced intervening secondary elemenc, into Che hopper. The ball separated the water and the fresh concrete and pushed the water ahead The construction process for secondary elements of itself aut of the mouth of Che czemie. This was identical to that described above with the procedure was abandoned due to the realization following exceptions: First, the excavation was that the hydrostatic head in the deep hales accomplished using a clam shell which followed collapsed the ball causing a loss of seal in the walls of the adjacent primary elements the tremie and a subsequent segregation and wash- Figure 74!. This procedure removed the annu- ing o f the concrete. lar grout on one side af the primary elements and insured a concrete to casing bond once the The techn'ique selected to replace the basket- secondary elements were concreted, Second, rhe ball was Lhe use of a pine sphere produced at secondary e lements were excavated through ben- the site. While this did resolve the question tonite slurry for their full depth since they were noc cased. a. Loop is used to raise tremie as sections of pipe are removed. Tremie pipe is supported by coupling resting on plate. b. Tremie pipe being raised. Note how plates open to allow passage of couplings. Figure 73. Tremie support scheme. 91 Figure 74. Secondary element excavation device. The curved sections ride the ad]scent primary elements. Figure 75. Cores taken from primary element, p-773. Note variations in concrete quality. 92 of bal 1 collapse, the wooden bal ls did not fit the boles particularly the primary elements. snugly inside the rremie pipes neither did the If the pipe vere not centered, there was basketballs! Figure 76!. There is approxi- passibility of inhibiting the flow of the con- mately 0. 25 in. .64 cm! clearance between the crete as it left the cremie mouth. To elimi- pine sphere and che tremic pipe; therefore, as nate this possibility, centering fins were the ball and concrete moved vertically down the added to one secrion of the tremie pipe Fig- pipe, sorse amount af washing of the concrete ure 78!. Cores taken after addition of the was taking place. fins conte inued ta shaw anomalies, indicating that poor centering was not the sole cause of The procedure followed to introduce the first the poor quality concrete. concrete into the tremie was also designed ta guard against loss of seal. The pipe was ini- 4.3.5 Concrete lacement rate. In large valume tially raised only 0,3 ft 9 cm! as the first placersents such as Pier 12 of Chapter 3! the concrete was placed. After about 40 seconds placement rate of tremie concrete is often an approxirsately one cubic yard .8 m3!!, the area of concern. Too slow a placement rate tremie was raised an additional 0.6 ft 8 cm! allows the concrete in place to stiffen which to allow the pine sphere to escape. By the inhibits flow. Table 22 examines placement time the tremie was raised this second incre- rates for six elements at Wolf Creek far vhich ment, sufficient concrete had been fed into the data were available. These rates are based tremie to insure that the rsouch was adequately upon total elapsed time from beginning ta end embedded. of the placement and, ther afore, include time far removal of pipe sections, waiting on con- Although there was undoubtedly leakage around crete trucks, etc, the sphere, a zone of poor quality concrete has nat been consistently found at or near the The lower volumetric rate yd3/hr ! m /hr! for bottom of various elements as would be expect- the primary elements is a reflection of the ed. Perhaps the Iaitance or abashedmaterial was more frequent stopping for removal of pipe carried upward on the sound concrete of perhaps sections. Yec even with this slower volumetric it was Lost as an identifiable area due to re- rate, the primary elements have a higher 1 inear mixing. There is no evidence ta indicate that rate ft/hr! m/hr! duc to their smaller cross- che zones of poor quality concrete found sectional area. The linear rate appears to be throughout the vertical sections are a result signif icantly higher for the primary e lersents. af initial. leakage around the sphere. Finally, chc queston remains, if the leakage were re- Although problems with race are usually associ- sponsible for the poor qualiry concrete, why ated with too slav a placement, perhaps too was the problem evident only in the primary rapid a rate may also be decrimental. No elemencs? reports on the effects of too rapid a placement have been found in the literature, Intuitively, One possible explanation relates not to the however, a higher rate would seem to favor leakage but to che sphere itself. Due to the remixiag within the elements as the concrete size of the primary elements, it was not possible is placed. for the sphere to pass the tremie on the way back up to casing Figure 77!. Perhaps the 4.3.6 Tremio rersoval rate. An aspect closely sphere vas following the tremia as it vas related to the placersent rate is the rate at withdrawn and was inhibiting concrete flow and which the tremie pipe is raised as sections rersixing. Since the secondary elements were are removed thc mouth of che tremie rsust larger, the spheres were able to return to the remain embedded in the concrete!. Here, the surface without causing a problem. theory is that too rapid a pull rate could result in voids or honeycomb i f the concrete 4.3. 3 Tremie aint leaka e, One factor which did not flow fully into the void left by the is often suspect in cases of vertically scat- cYemie pipe. This problem is particularly pre- tered paor concrete is leakage between joints valent if overall placement rates are low, in the t'remie pipe . The rapid downward flow af concrete in the cremie can suck water through To guard against too rapid removal of the pipe any leaks which may be present at the joints. from the e laments, an inspector timed and The resulr is a randomly washed and segregated recorded the pull rate for each section of the conr.rete. trersie. The same rate .3 ft/sec! 9 cm/sec! was used for both the pr imary and secondary At Wolf Creek the cremie sections were threaded elements. together and the threads vere liberally covered with grease each time the cremie was assembled, Again, the question may be raised as co why The secr.ians vere carqued toge cher by tvo men the problems, if a result of pipe pull speed, while a third hit the pipe with a sledge hammer were evident in only the primary elements, to tighten the connection. The tremie was This question is particularly bothersorse since tested for leakage by lowering a light inside the tr ernie sections were removed more frequently and found ca be satisfactory. From the pre- from the primary elarsents. Hence, the concrete cautions being taken, it is doutbful that tremie had less time to stiffen and Lose the ability leakage was causing the problems. co flaw inta the void created by the withdraw- ing tremie. Therefore, if pipe removal rate 4. 3.4 Tremie center in, Another potential were a factor, the problers vould seem ro be problem area was the centering of the tc'ernie in Loss likely to occur in the primary elements. 93 Figure 76. Note Pine leakage sphere insidearound tremiesphere. at beginning25-/h/ of O.O. placement.CASII|IG /25.44N./.D / VN.I.D. hIIEPIPE D I/I CEh/TEII I/VS h/.DIAh/. SIIPERE Figure 77. Position of pine sphere upon leaving tremie. Note possible inhibition of concrete flow in. = 2.54 cm!, 94 Figure 78. Pins added to tremie pipe to insure proper centering. TABLE 22 TRENIE CONCRETEPLACENENT RATES Volumetric Elapsed Volume of Element Depth Linear Rate, Rate Element Time, Concrete, ft m! ft/hr m/hr! hr ln3 /hr! P611 212.8 4.9! 193 9! 30 3! 27 1! P771 1.2 212.1 4.9! 177 4! 29.5 3! 25 9! P773 1,4 213,1 5.0! 152 6! 29.5 3! 21 6! F791 212.9 4.9! 194 9! 30 3! 27 1! P795 1.2 212.9 4.9! 177 4! 30 3! 25 9! F807 1.2 212.7 4.8! 177 4! 29.5 3! 25 9! F985 0.9 173.2 2.8! 192 9! 25 9! 28 1! P1001 0.9 173.3 2.8! 193 9! 25 9! 28 1! PRIHARY ELEMENTAVERAGE 182 6! NA NA 26 0! 8576 1.6 212. 5 4. 8! 133 1! 72 5! 45 4! 8594 1.7 212.6 4.8! 125 8! 72 5! 42 2! 8676 2.1 212.7 4.8! 101 1! 75 7! 36 7! S746 1.8 212.9 4,9! 118 6! 73 6! 41 1! 8858 2.2 263,2 80,2! 120 6! 97 4! 44 4! 8956 1.5 172,7 2.6! 115 5! 64 9! 43 3! SECONDARYELEMENT AVERAGE 119 6! NA NA 42 2! 95 -,.3.7 Breaks in lacin . Another area of con- appeared to be of the same quality as that cern was the resumption of concrete placing at which was being supplied to the tremie Figure the beginning of each new truck load. A certain 79!. amount of sand and laitance does collect on the top of the tremie concrete as the placement Another area which had been questioned was how moves up the hole. To prevent trapping this to determine when sound concrete had t'cached material and to insure a better remixing at the the top of the elements. For the primary resumption of placement, the initial amount of elements there was no difticulty making this concrete was trickled into the tremie. The determination, Initially, clear water aver- remainder of the load vas unloaded at normal f loved the casing. Hear the end of the place- speed. This same procedure was followed vhen a ment, the small amount of slurry which was truck laad was broken into two placements to added to the pr imary elements began to appear. allow removal of a tremie section. As can be This slurry gradually thickened and contained seen from the figures in section 4,3,11, below, more and more granular material. Approximately there does not appear to be a correlation be- 12-18 in. 130-46 cm! of very granular material tween stopping/ restarting points and zones of came to the surface before a concrete contain- poor quality concrete. ing fine and coarse aggregate was visible. This concrete appeared evenly on all sides af 4,3,8 Water tern erature durin lacement. In the tremie and had a very uniform appearance, the original construction sequence there vas Before the retarder vas added, elevation nat a delay between placement of the grout in differentials of up to 18 in. 6 cm! on opposite the annular space surrounding the primary sides of the tremie were reported as the elements and placement of the tremie concrete concrete began to return.! in the elements. The temperature of the water in one element was measured at 100 F 8 C! due to the heat generated by the hydratian of cem- The placement of the concrete in the secondary ent in the annular grout. placement of tremie element vas identical to that in the primary cancrete into hot water can result in rapid and elements except that all fluid which was dis- unpredictable setting or loss of slump, both of placed vas slurry rather than water. The same which could inhibit f lovability, In one in- thickening of the slurry was noted and, again, stance, a rapid set required removal of a por- there was no difficulty determining when sound tion of the concrete in an element. concrete had returned, These problems let to the practice of alloving As of the date of this visit, none of the 10 days between placement af annular grout and elements containing the retarded mix had been tremie concrete. The water in t' he primary cored. The personnel at the site agreed that elements vas also exchanged for cooler water the placements had been very successful and prior to concrete placement. were quite confident about the expected coring results. Although this change in procedure did eliminate rapid set problems, it did not preclude the 4.3.11 Care and Iacement~lo s. The Iesults concrete quality problems as described. obtained from coring those elements which vere observed being placed were surprising and 4.3,9 Concrete mixture. One area in which disappointing. While the secondary elemencs there was a naticable improvement was the tremie continued to be free of problems, the zones of concrete mixture itself, Characteristics of poor quality concrete continued ta be found in the mixture are shown in Table 23. This mixture the primary elements. While the problems did is of particular interest due to the use of the not appear to be as severe as before the addi- fly ash vhieh was used to improve workability tion of the retarder, they were still evident. and to reduce heat generation. The Resident Engineer established an excellent None of the problems observed have been attri- system for inspecting, and recording the work, buted to the mix. However, the slump loss excavation, tremie concreting, and coring. characteristics of such a rich mix and the Reports vere filed on a day by day and on an high ambient temperature at the site suggested element by element basis. Using the records that the addition of a retarder to the mix of four placements and the corresponding core would be beneficial. A retarder was added and logs, Figures 80 through 84 vere prepared in subsequent pl.acements appeared to be very an attempt to correlate zones of poor quality successful. The Resident Engineer stated that concrete with any of the fo11owing factors: the retarder made a significant difference, most noticeably in the appearance of the con- Initial pipe embedment; crete as it returned to the top of the holes at Breaks in placement ta withdraw tremie the conc!.usion of a placement. sections, and; Location of the end of the tremie. 4.3.10 Obervation of lacements. Shortly after the addition of the retarder to the mix, As can be seen by studying these figures, none one of the authors of this report Holland! of these factors appears to be related to the visited the site and observed placement of zones of poor quality concrete. several primary elements and one secondary element. During the placements which were ob- 4 . 3, 12 Tremie resi stance to flow. Another served, the concrete returning to the surface area considered vas the balance of the tremie 96 TABLE 23 TREMIE CONCRETEMIXTURE, WOLF CREFX DAN Figure 79. Primary element at completion of tremie placement. Concrete returning to the surface appeared to be of excellent quality. 97 l. Each Figure 81 through 84! presents an analysis of the tremie pipe location on the lef t of the page and a summaryof the core log on the right of the page. 2, Each ver tical line represents placement of concrete from the bot tom to the top of the line. The tremie is fixed during each placement with the mouth at the bottom of the line. 3. Example: shows placement from -63 ft, When concrete tremie mouth was 75ft.Embedment atStartof Lift Embedment at End of Lift Figure 80. Key for Figures 8l through 84. All distances and elevations in feet ft = 0.3048 m!. 98 SAND SEGR EGATION BMALLAGGREGATE SEG R EGATION MODERATELYHONEYCOMBED SLIGHTLYTO MODERATELY HONEYCOMBED MODERATELY TD BADLY HONEYCOMBED BADLY HONEYCOMBED SLIGHTLY HONEYCOMBED SLIGHTLY TO MODERATELY HONEYCOMBED BADLY HONEYCOMBED MODERATELY HONE YCQMBED SLIGHTLY HONEYCOMBED ! BROKENBY DRILL 212.7 BOTTOM OI' CORE ING Figure8l. Analysisof element P-611. See Figure 80for explanation. Al?distances and elevatlons are in feet ft 0.3048m! . 99 VERT SEAM 24 BADLY HONEYCOMBED 35 SAND SEG R EGATION BADLY HONEYCOMBED SAND SEGREGATION ~j MODERATELYHONEYCOMBED SAND SEGREGATION 119.0 RAN INTO CASING BOTTOM OF CASING Figure 82. Analysis of elementP-985. SeeFigure 80 for explanation. A11 distances and elevations are in feet ft 0.3048 m!. 100 SANO WASHED ~ BROKENBY DRILL POROUS CONCRETE SLIGHTLY HONEYCOMBED SLIGHT SAND SEGREGATION 104.9 RAN INTO CASING TTOM OF CASING Figure83. Analysisof element P-1001. See Figure 80 for explanation. All distancesand elevations are in feet . ft 0.3048!. 101 SAND SEG R EGATION SOLID CORE! 207.5 INTERCEPTED LIMESTONE Figure 84. Analysis of element S-576. See Figure 80 for explanation. All distances and elevations are in feet O ft 0.3048!. 102 system when flow a was not occurring due to There is no reason to believe that the poten- breaks in the placement. This balance may be tial for segregation was different for the thought of in terms of resistance to .flow which primary snd secondary elements. may be calculated as the difference between the theoretical hydrostatic balance of the tremie 4L .rf ftl gr'*rri system and the actual measured value. The placement: difference which is obtained may be attributed co friction between the concrete and the tremie 1, A concrete cutoff wall was constructed pipe, to internal friction or cohesion of che through an existing esrthfill dam using tremie- concrete, or to a blockage or any other type of piaced concrete. A total of 1,256 individual restriction to flow. Figure 85 shows the geo- elements were constructed, with the deepest metry of the tremie system snd che technique trernie placement being approximately 280 ft 85 used co calculate this resistance to flow. nr! . Heasuremencs made on ocher projects have in- 2. The cutoff wall vas made up of alternating dicated that che tremie system is normally very cased primary! and uncased secondary! elements. close to the balance point and very little The primary elements were cased with 26 in. 6 resistance to f!ow can be measured . One set of cm! diameter steel pipe, The secondary elements measurements vss made by Gerwick st Wolf Creek. were rectangular and were slightly wider than This data is presented in TabLe 24.* the primary elements, Their volume was approx- imately cwo and one-half times char of the The resistance to flow varies greatly from primary elements. measurement to measurement. The variations in the rangeof 500 to 1000Lb/ft2 .39 x 104 to 3. An extensive coring program hss shown the 4.79 x 10 ps! are believed to be typical. quality of the concrete in the secondary Ho~ever, note readings number 1 and 4 which are elements to be excellent. The concrete in the an order of magnitude greater than the remain- primary elements has been plagued with minor but der. This variation is not believed to be persistent problems of segregated materials, typical, It was not possible to correlate these trapped laitance, and moderate to severe measurements with a core log of the element. honeycomb. The anomalies are scattered ver- tically and horizontally within the primary While these variations in resistance to flow elements and do not seem to follow any pattern. are not believed to be causing the problems seen in the concrete, they may be indicative of 4. The construction of the tremie concrete cut- a blockage or other restrictions to concrete off wall has been a highly successful operation flov which could result in the anomalies de- which will help to insure the continued safety tected. Lf these variations are related to of the structure, Since the concrete problems zones of poor quality concrete, measurements were limited to the cased elements, there is no made inside and outside the tremie pipe during reason to believe that the wall will not perform placement could serve as an additional inspec- its indended functions. tion tool. Further research should be con- ducted in this area. 5. An examination of the mixture design and var- ious aspects of the placement technique such as 4.3. 13 Potential for concrete se re ation. The starting procedure, joint leakage, tremie data used to develop the resistance to flow centering, placement rate, tremie removal. rate, values also show that a significant potential snd breaks in placement has failed to disclose a for segregation occurred whenever there was a single, responsible factor for the small local- break in the placement. Since the system returned ized areas of poor quality concrete. Instead, very near'ly to the balanced point, concrete the problems are beLieved to result from the placed isnnediately after a break could have interaction of at least two factors. First, the fallen through distances great enough to cause concrete was probably segregating during its fall segregation. through the tremie pipe. Second, the concrete in che secondary elements wss apparently remix- ln massive tremie concrete placements the flow ing and overcoming the segregation while the of the concrete through the tremie is con- corrcrete in the primary elements wss not as trolled by the depth of the pipe mouth embed- successful in remixing. The inhibition of re- ment in che fresh concrete. Such control was mixing in the primary eLements is believed to be not possible in the limited volume placements due to the following items: of Wolf Creek since the concrete in the ele- mencs did noc have adequate time to stiffen and s. The primary elements had s much smaller cross be able co control the flow. Therefore, not sectional area than the secondary elements. only the concrete placed after breaks but also This smaller ares msy have been acting in con- mone of the concrete placed msy have been sub- junction with the wooden sphere and centering jected co long free falls resulting in segrega- fins to create a condition which restricted tion. flov and remixing. b, The walla Of the permanent caeinga WhiCh Were fiLLed to create the primary elements were much smoother than the walls of the secondary «Additional data concerning resiscsnce to flow erements. These smoother walls may have reduced is avaiLable in re ference 30. 103 WORKPLATFORM WATERSURFACE MEASUREDCONCRETE LEV EL . INSIDEPIPE MEASUREDCONCRETE LEVEL- OUTSIDEPIPE REMIEPIPE TIP NOTE;ATPIPE TIP: by ey + ay + RESISTANCETOFLOW! REslsTANcETo Fl.ow= !b-a!y -ey carte water' FigureS5. Tremiegeometry and derivation of reaiatanceto fIow. TABLE24 TREHIE RESISTANCETO FLOWMEASUREMENTS NOTES.' ! Deck 3 ft . m! above water ! Unitweight of concrete147 1b/ft '355 kg/z ! ! Unitweight of water63 1b/ft ,OO9kg/z3! 104 the tendency of the concrete to tumble and remix. The slurry put into the primary elements st the beginning of a placement may glen have reduced wall roughness and thus contrjbutdd to the problem. I c. The concrete wss placed in the prfmary elements very rapidly. The rate may have been too rapid to allow for adequate remixing to take place. 6. A definite reduction in concrete problems wss seen over the duration of the project. This reduction may be attributed to s series of modifications in the placement technique snd to the addition of s retarder to the con- crete mixture. All of the modifications enhanced the flowability of the concrete and therefore contributed to better remixing in the primary elements. Since the effects of these modifications were cumulative, it is impossible to state which made the greatest difference. The Resident Engineer strongly believes that the addition of the retarder to the concrete mixture was the most significant change. 7. Measurements made to determine the state of hydrostatic balance of the tremie system are postulated to be an indication of areas in which to expect anomalies to occur. Additional measurements snd correlations with core logs need to be completed to evaluate this hypothesis. CHAPTER5 and gradients based upon changes in placement TENPERATUREPREDICTIONS POR TRENIE CONCRETE temperature, cementitious materials types and amounts, and placement x'aces, of the project was co develop a generalized 5.3. Observations and discussion finite-element approach for predicting tempera- tures in massive tremie concrete placements. 5 ' 3,1. General descri tion of ro ram TENP. Emphasiswas placed upon developing a program The progrars which was developed, TENP, produces which, given the characteristics of the place- impuc data compatible for use with program menc, would develop an appropriate grid system DETECT, The output available includes element end output the grid in a format suitable for identificatian and creation information and an use as input to an independent finite-element appropriateheac generation function. A listing program which would perform the temperature of program TENPis in Appendix K. calculations. The user of px'ogramTENP has the fallowing 5,2 Back round. options: 5,2.1. Need for finite-element anal sis. The 1, Very placementgeometry. use of a simple one-dimensional technique Carlson Nethod! for predicting tersperature 2. Vary placement rate. development in a tremie concrete placement has been described in Chaptex 3. As was noted 3. Vary heat generation characteristics of the there, this technique accurately predicts tem- concrete being placed. pex'acure development in the center of the mass where hear flow in other than the vertical 4. Use of incremental or naniacremental con- direction may be neglected. Hawever, che struction approach. technique is not applicable to areas near the excrerses of the placement. These areas ax'e of 5. Useof ownracher than programgenerared grid particular interest due to the possibility of system, thermally-induced cracking as was also described in Chapter 3. 6, Use of own rather than programgenerated hest func tron. It was felt that the best way to obtain the tempex'ature distribution at the boundaries of 7. Vary site conditions to include effects af the structure was to develop a capability to per form e finite-element analysis of a tremie insular ing surf aces,if any. insulating s ur- plaeersent. faces are handleddirectly throughinput to program DETECT.! 5.2.2, Finite-element ro ram selected, The 5.3.2, Usero cions and variables. Following finite-element programselected to perform the is a detailed description of Cheoptions avail- analysis was one which is carmsercially avail- able to the user and a description of how these able ac U.C. Berkeley, It was developed by options relate to the variables which are Ronald N. Pal ivka and Edward L. Wilson in 1976 ref. 33!. This program, entitled DETECT involved in a typical tremie placement. Detailed DEtermination of Tlbrrperaturee in ConsTruction!, user instructions for program TENPare in Appendix L, while instructions for interface provides a two dimensional linear analysis of with programDETECT are in Appendix N. structures constructed incrementally. A complete Listing end description of the progrars may be found in the reference. 1. Pier geometry. The length, width, snd thick- ness of the concrete placement may be varied aS desired. The OrienCatiOn Of the aXeS iS aS 5.2.3. Crackin redictions. Prediction of shownin Figure 86. Elements are generated temperatures in a massive concrete placement for input co DETECTfor two-dimensionalanalysis is only the first step in predicting if ther- in che X-Y plane. mally-induced cracking will occur. Borh the factors which rend to cause cracking primarily 2. Trerxie locacion. The programassumes that tersperature changes for tremie-placed concrete! and those factors which resist cracking one tremie pipe, located at 0.0 on the X-axis, tensile creep and strength of the cancrete! is in use in any plane perpendicular ta the rsust be examined. A detailed examination of 2-axis. Additional tremie pipes maybe simu- lated by adjusting the placement rate as is these factors is beyond the scope of the described below, present work. Carlson, Houghton, end Polivka ref. 34! present an excellent overview of the 3. Grid genex'ation. The programwill auto- factors involved in cracking of mass concrete, matically generate an appropriate grid, or the Therefore ~ development of a program which will user may input e specific grid, if desired. allow predictions of temperatures in massive tremie placementswill not lead directly to The automatic grid generation option establishes predictions of cxeeking. However, use of che a rwa-dimensional grid which will allow for an programwill allow comparisonsof temperatures 106 adequate evaluation of the temperature distri- 6. Concrete heat generation. The user is bution within any size structure while mini- asked to specify the amount of cement and mizing the numberof elements necessaryto pozzolan in the mixture to be evaluated . Three define the structure fox the finite-element heat generation curves are then available for temperature anal.ysis. The grid spacing gener- selection.* Thesecurves represent a typical ated is the most intense at the boundaries of Type 1 cement, typical Type II cement, and a the structure where the temperature gradients higher than averageheat TypeII cement.The are expected to be the greatest. The grid cementand pozzolandata is used in conjunc- decreases in intensity near the center of the tion with the curveselected to producethe structure . heat generationfunction used as input for DETECT, In Figuxe 81 a total of six grid spacings are illustrated for different base lengths and Theuser alsohas the option of modifyingany heights. For.a given structure, the base and or all of the 13 points which makeup eachof height gride are created and then superimpos- the three available curves by entering desired ed to obtain the two-dimensional grid pattern, multiplication factors. Prom Figure 87 it can be noted that the base Finally, the user has the option to completely grid is established using even20, 10, 5, 2, bypass this portion of the programand enter a and I ft .1, 3.0, 1.5, 0.6, and 0.3 m! heat generationfunction directly into program intervale from the center outwaxd with a DETECT. standard boundary established at the outside edge of the structure. The height grid is 7. Boundaryconditions. Values for the follov- created using a similar schemeexcept that ing variablesmust be entereddirectly into the spacing is based upon 10, 5, 4, 2, and 1 DETECT:concrete placement temperatux'e, ther- ft .0, 1.5, 1.2, 0.6, and 0.3 m! intervale mal characteristics of concrete, water tempera- with standardboundaries at the top and base ture during and after PIacement, insulation of the structure, In addition, two founda- characteristics, if any, and thermal character- tion elements with boundaries 10 and 20 ft istics of foundationmaterials. Thenumber of .1 and 3.0 m! below the base of the stx'uc- time periods to be included in the evaluation ture are included in the grid layout. is alsohandled directly by DETKCT.See hppen- dix M and the user instructi.ons f'or DETKCTfor The grid interval at all boundaries is set at more details concerninginput of these varia- 0.5 ft ,2 m!, a spacing foundto provide an bles. adequate definition of the temperaturedistri- bution at the boundaries. 5.3.3 Examle of ro ramTEMP usa e. Programs TEMPend DETECTwere used to producetempera- The automatic grid generation is recosssended ture predictions for a placexsent similar to for use in preliminaryanalysis. If desired, that of Pier 12 of the I-205 Bridge described the automatic spacingsmay be modified by earlier in Chapter 3. Variables were selected changing the appropriate values in subroutine to be consistent with those in the actual GENGRDin program TEMP. placement. 'Table 25 presents the values of the variables involved, 4. Incremental construction, The normalmode for the program is to create elements at The option for a continuous placement rate of appropriate times in accordance with the 150yd3/hr 15 m3/hr!was selected for pro- placement option selected. There is also the gramTEMP. This rate corresponds well to the option of creating all elementssimultaneously. actual averageplacement rate of 135yd3/hr 03 m3/hr!. 5 . Concrete placementrate . There are three options available: Twoof the optional heat curves available j.n a. Constant rate of concrete rise over the programTEMP Type II averageheat cementand entire placement area. The user is asked to Type II higher than average heat cement! were specify a production rate yd /hr! m3/hr! or usedto produceheat function input data for a total time to complete the placement for program DETECT. Additionally, three other this option. heat functionswere used by beinginput direct- b . Specified rate of rise at center tremie ly into DETECT. Table 26 shows the values pipe location! or at the X-boundary.This associated with these five heat functions. rate is then constant over the entire suxface. c. Specified x'ate of rise at center and at X- Temperaturespredicted by ProgramDETECT boundary.When this option is selected,a using input generatedby ProgramTEMP are linear variation is used between these two points, The production rate specified for the center is usedas a constant along the Z- axis. * Thesecurves are takenfrom those shownin Reference 34. 108 TOP SURFACE250 6! TOP 24.5 .5! SURFACE330 IO.I! TOP 24.0 .3! 32.5 9,9! 3 I .0 9.4! IO.O .0! 239 .0! 9.5 .9! 2I.O .4! 29.0 8.8! 9a .7! I 7,0 .2! 25.0 .6! 89 .4! I3D 0! 2 I.O 6.4! 7.0 .I ! ea 4! I7.0 5.2! 5.O I.s! 6.0 I.e! I2.0 3.7! 3.0 .9! 4.0 I.2! 8.0 2.4! 2a .6! 29 .6! 40 I .2! I 9 .3! I 0 3! 2.0 0.6! OS 2! 0.5 2! 0.5 0.2! OQ .0! OD .0! OQ 0.0! -IO.O eo! -IO.O ao! -10.0 -3.0! -20.0 KI ! -20' {4.I ! -209 -6. I! a. TYPICAL VERTICAL GRIOS, FT. m! OUTSIDE SURFACE 0.0 M 70 8.0 80 $5 IM 'a! I.S! '.I! N.4! .7! R9! 0! OUTSIDE SURFACE 0 7.0 ap! I,5! .0! ,6! .I! 7! .3! .6! .9! S.I! 8.2! OUTSIDE SURFACE 0.0 GO 209 25.0 3QO 35.0 370 39.04M 420 43.0 4M 44.0 ,0! 0! .t! .6! 9.I! l07! II.3! I1.9! I2.5! I29! I3.l 33! I34! b,FfPICAL HORIZONTALGRIDS, FT. m! Figure 87. Typical finite-element grids generated by ProgramTENF schematic no scale!. 109 TABLE 25 VARIABLES USED IN EXAMPLE PROBLEM X: 54.0 ft 6.5 m! Y: 33.0 ft 0.1 BL! 2: 142.0 ft 3.3! 3 3 Total volume: 9372 yd 166 m ! Placement rate. '150 yd /hr 15 m /hr! Foundation material: Thermalconductivity: 0.917 BTU/hr-ft-'F .59 W/m-K! Specific heat; 0.194 BTU/Ib-'F 812 J/kg-K! Density: 125 lb/ft3 002 !rg/m3! Concrete: Thermal conductivity: 1.30 BTU/hr-ft-'F .25 W/m-K! Specificheat: 0.2 BTU/lb'F 967J/kg-K! Density;148 lb/ft 371 !sg/m3! Concrete lacement tern erature: 60 F 6 C! Water Tem erature: 55 F 3'C! Mixture ro orations: Used for heat functions generated internally by Program TEMP! Cement:526 lb/yd 3 12 kg/m3j Pozzolan: 165 lb/yd 98 kg/m ! 26 - HEAT FUNCTIONS USED FOR TEMPERATUREPREDICTIONS+ Tame, Type II, Type II, Heat Heat Heat hrs Average higher than Function Function Function heat*a ~Ae * tl k2 k3 0 0 200 200 200 0 2 79 82 30 30 30 88 90 100 100 100 48 6103 105 106 106 106 75 75 60 12 109 110 20 64 65 20 20 15 32 27 28 10 10 14 48 ll 15 15 15 13 60 7 10 15 12 12 96 4 1 6 2 10 10 180 5 1 51 3 290 0 32I 1000 0 0 0 0 3 3 * Values shown are BTU/Ft -hr. Multiply by 10.34 to obtain W/m , eeCurves available within program TEMP. 110 compared to temperatures measured in Pier 12 In addition to the comparison made with actual in Figures 88, 89, 90 and 91. For these measured temperatures, curves were prepared figures, representative temperature instruments showing temperature variations horizontally and at various locations in the seal were selected.* vertical l.y within the seal. These curves were Then, the finite-element node closest to the prepared for the heat function based upon the instrument location was determined. The higher than average Type II cement as is avail.- figures show the measured temperatures as well able within Program TEMP. Figure 92 shows ehe as the predicted values based upon all five heat locations of the nodes which were plotted while functions. Figure 93 shows horizontal variations and Fig- ure 94 shows vertical variations. Figure 88 presents measured temperatures for two instruments located at mid-depth in the Using the data presented in Figures 92 and 93, seal, on the centerline X ~ 0. Y ~ 18.5 ft two additional figures were prepared which show .6 rn! for Program TEMP!, temperature gradients within the seal concrete at 80 and 200 hours after the beginning of the Figure 90 presents measured temperatures for an placement. Figure 95 shows the gradients which instrument below mid-depth, off of the center- exist across s horizontal plane 12 ft .7 m! line X 13,0 ft .0 m!, Y = 10.25 ft .1 m! above the base of the seal. Figure 96 shows for Program TEMP!. the gradients which exist in a vertical plane ae the centerline of the seal. Mote that these Figure 91 presents measured temperatures for two figures are plotted as temperatures of two instruments located at mid&epeh near the concrete above the temperature of ehe water outside of the seal X 23.7 ft .2 m!, surrounding the seal. Y ~ 18.5 ft .6 rn! for Program TEMP!. The following points can be made concerning The following points may be made concerning these figures: these curves: 1. Significant temperature gradients can be 1. The predicted temperatures are in good expeceed to develop near the outside surfaces general agreement with the measured values. of a massive tremie-placed seal. These gradients develop soon after placement begins and remain 2. There does not appear to be one heat function evident for a significant period of time. which provides the most accurate agreement in all cases. The curves based upon the Type II 2. The gradients predicted by the finite- average heat cement are close in Figures 89 element program are consistent with the data and 90 while the curve based upon heat function obtained in the Pier 12 seal placement described two appears to be the closest in Figure 88, in Chapter 3. The curves based upon heat functions one and three appear to be the closest in Figure 91. 3. Without specific strain capacity and modulus data, predictions of cracking cannot be made. 3. The predicted temperatures are obviously However, the temperature gradients appear to very dependent upon The heat function used. be large enough to be capable of inducing Minor differences in the heat functions can cracking in most concretes. lead to major differences in predicted tempera- tures during the period of interest. If pre- dictions of actual temperatures within a place- this portion of the project: ment are desired, it is reconnnended that the concrete to be used be tested to develop an l. A Fortran program, TEMP, was prepared accurate heat function. However, if relative which accepts variables associated with a predictions concerning the effect of changing massive trenie placement and processes those placenent variables such as placement tempera- variables to develop input for. an existing ture or cement or pozzolan content are desired, finite element program, DETECT, which can be the heat curves built into Program TEMP used to predict temperatures within the tremie should be adequate. concrete. Program TEMPhas a wide range of options available to the user to allow 4. The sensitivity of the temperature predic- accurate modeling of s planned placement. tions to variations in difficult-to-define variables such as the thermal characteristics 2. Predictions of maximum temperature and of the conci'ete and the underlying rock was temperature gradients near sur faces of tremie- not examined. Such an examination is recom- placed concrete made using programs TEMPand mended prior to use of the program for actual DETECT were shown to be in good general agree- temperature predictions. ment with temperatures measured in an actual placement. 3. Predicted temperatures were shown to be very dependent upon the heat function used. The sensitivity to other variables was not explored. " Temperature instrument locations are pre- sented in Appendix H, 18O 82.2! 170 a 160 1,1! 0; 150 I- I- IIJ 0: 140 o,o! 130 120 8.9! 50 100 150 200 250 300 350 TIME SINCE BEGINNINGOF PLACEMENT,HRS. Figure 88. Predicted versus measured temIperatures, centerline, mid-depth. 12 H.F, +1 8.9! I IO s IOO I 7J!! 4I 90IIJX LIJ IIJ 80 O~ 6.7!70 O 60 5,6! TIME SINCE BEGNNING OF PLACEMENT, HRS. Figure 89. Predicted versus raeasured tIssperatures, outside edge, upper surface. ««+ 160 I. I ! I 50 o l40 0.0! X laI 0 ILI I- IaI l20 9 8.9! O O I I 0 IOO 7.8! 0 50 60 l50 200 250 300 TIME SINCE BEGINNINGOF PLACEMENT,HRS. Figure 90. Predicted versus measured temperatures, off center- line, raid-depth. H.F. + I l40 0.0! I 30 o l20 ~ 8.9! 4 X IIO LLI l00 ~ 7.8! O O 90 80 6.7! TIME SINCE BEGINNG OF PLACEMENT, HRS. Figure 91. Predicted versus measured temperatures, outside edge, mid-depth. 113 33.0 TOP OF SEAL IO. I! 32.5 l44 9.9! ~ indicates node and I33 3 I.O node number locate. 9.4! l22 29.0 8.'8! 2 I.o IOO .4! 80 82 84 8687 I2.0 78 ~ OO .7! 4.0 56 I.2! 0.0 23 00 I QO 200 24.0 26.0 X .0! . I! .3! .9! FT. m! P8.!!IBS! Figure 92. Section through seal showing locations of nodes plotted in Figures 93 and 94. 114 I70 6.7! I50 5.6! 4 l 30 ~ 4.4! 5 0' * llo jD X g 3,4! 64 O 0X 90 Z 2.2! O O 70 l.l! 50 000l 0 50 l00 l50 200 250 300 TIME SINCEBEGINNING OF PLACEMENT,MRS. Figure 93. Horizontal variation in predicted teuperatures. See Figure 92 for location of nodes shown. l70 78 6.7! l50 5.6! 56 4 I 30 4.4! E l ~ 3.4! I- LJ l33 90 ~ 2.2! O 70 I. I ! 50 IOO! TIME SINCEBEGINNING OF PLACEMENT,MRS, Figure 94, Vertical variation in predicted temperatures, See Figure 92 for location of nodes shown. 115 4 u Ill B ~ 00 a m R eSI al ba 0 W Ql 0 0 al 0 g be N u 0 Ch Cl dO $P IBe PO ~e! O tO Ã! +! i9 lV3S 30 3@f8 3h085 39NVLSI0 lf38 W 3M3 3JOSihO C 4 Cf u u I4 g O-. cvgj 00 0 u 8u al u 0 al al ~ b04 4 O Z ao 0 aI 4 aI 0 OD u g al M 0 4 0 4I 4 u 0 N V g a0 Oa! 3a '83lVhh SNIONA088AS3AO9lf 3L380NOO W 38AJV83dW3A CHAPTER6 FLOWPREDICT1ONS FOR c. The maximum distance from s trernie to a TREMIE CONCRETE farra should not be greater than 10 ft ,0 m!. d. The deprh of embedmentshould be a minimum of of the project was to examine the possibility 3 fc .0 Til!. of using a computer model to predict flaw patterns of tremie-placed concrete. Two areas e. Vertical rise of the concrete should be relating to tx'ernie concrete flow were of partic- 2 fr/hr .6 xa/hx'!. ular interest. first, the relationship of con- crete placement rate and pipe spacing to con- 4. Concrete Construction magazine ref. 2! made crete quality; and second, the influence of the similar recosnaendations which included coverage depth of cremie pipe ernbedrnentan the flatness per tremiepipe of approximacely300 ft2 8 ra2! a f the completed concrete sur face. Additional- ar a spacing of 15 ft .6 ra! on centers, and ly, it was thought that if an accurate flaw chat a higher placement rate will lead to prediction model could be developed, that madel flatter slopes in the tremie concrete. A tate could be used in conjunction with the tempera- of concrete rise of 3 ft/hr .0 m/hr! was ture prediction programsdescribed in Chapter 5 recormnended. Concerning embedment, a depth of to increase the accuracy of the temperature 2 ta 5 ft .6 to 1.5 rn! was given with the predictions. cormnent"to get flatter sl.opes in che seal, a deeper embedmentis required." 6.2. Back round. 5. Gerwick refs. 4 and 5! also recossaended a 6,2.1. Literature review. A brief sampling of coverageof 300 ft2 8 m2! or 15 ft .6 m! the literature dealing vith tremie concrete centers for the tremies along with an embedment flow, pipe spacing, and pipe embedmentfollows: depth af 1.5 to 5 ft .5 ta 1.5 m!. He wrote "Deeper embedmentgives a flatter slope provided l. The American Concrete Institute Committee 304 initial set has not caken place." Concerning in its "Reconnnended Practice for Measuring, Mix- placement rate, Gexwick recommended1,5 to ing, Transporting, and Placing Concrete" 10 ft /hr .5 to 3,0 m/hr!, re f. 1! wr ites: 6. Ha1 loran and Talbot re f. 17!, vr i ting o f "Pipe spacing varies depending on their experiencesconstructing tremie-placed the thickness of placement and con- drydacks during World War II, made these gestion fram piles or reinforcement. comments: The spacing is usually about one pipe for every 300 sq fc approx, s. Tremie spacing should depend upon the con- 28 m2! of surface or abouc 15 fr. tinuity vitb which concrete is delivered to the approx. 4 1/2 m! centers. However, tremies. chin may be increased co as much as 40 ft approx. 12 m! centers in an b. The tremies should be spaced on 12 to 16 ft uncongested deep mass using retarded .7 to 4.9 m! centers with the outside trexaie concrete." being less than 9 ft .7 m! froxa the forms, The Cosnnictee also writes concerning the con- c. Closer spacing of tremies leads to flatter crete surface that, "Paster rates may produce surfaces. flatter surfaces" and "the deeper the embedment in concrete, the flattex' the finished slope d. A deeper embedmentof the tremie pipe leads will be." A placement rate resulting in a ta flatter slopes, with an embedment of 3 to vertical rise of concrete of 1.5 to 10 ft/hr 5 ft .0 to 1,5 m! recommended. .5 to 3.0 m/hr! is recommended. e. Placement rate should be sufficient to pro- 2. The Corps of Engineers in its Civil Works vide a rate of rise for the concrete of 2 to Construction Guide S ecification, Concrete 3 ft/hr . 6 to l. 0 xn/hr!. ref. 35 requires that a sufficient number of tremies shall be provided so that che maximum horizontal flow will be limited to 15 feet" The recarmnendations given by the authors above 6 m!. The Corps ' Standaxd Practice for vere based on experience gained on a wide Concrete ref. 36! reconnnends a 5 ft 1.5 m! variety af tremie placements. These sources embedment depth, but does not relate embedment may be summarizedas follows: Trexaiesshould depth to surface flatness. be closely spaced to minimize flaw distance; the greater the embedmencdepth af the tremie 3. Scrunge ref. 15! recommendedthe following: pipe, the flatter the surface of the completed placement:; and, the higher the concrece place- a. The coverage of each tremie pipe should be ment rate, the flatter the concrete surface. approximately250 ft 3 m2!. Typical numerical values for these reconmxenda- tions are: b. The largest horizontal dimension of the forms should be less than 15 ft ,6 m!. Partitions - pipe spacing: 15 to 40 ft ,6 co 12.2 m! on should be used to break up larger plaaements. centers. 117 pipe coverage: 300 ft2 8 m !. 3. "If there is suf ficient ismrersian depth, the concrete feed into the cofferdam will take place pipe embedment: 3 ta 5 ft .0 to 1.5 m!. in such a manner that concrete which is at the sur face will remain at the surface." This rate of rise: 1 to 3 ft/hr .3 to 1.0 m/hr!. statement, and figures in the Dutch report describe a horizontally layered flow pattern in Only one source was found in the literature which the first concrete placed may be expected which attempted a mathematical description of to be found on the surface of the finished these flow cansideratians. That work is des- placement. Such a flow pattern is inconsistent cribed in the next section. with the data obtained during the large-scale placement tests Chapter 2!. 6.2.2. Dutch investi ation. The work published by the Netherlands Corsmittee for Concrete 4, The concrete mound which builds up around the Research ref. 3! also included a chapter in tremie develops a slope of approximately 1:5. which the factors of pipe spacing, placement The mound continues to develop until the shear rate, and cremie ersbedment were treated in a resistance of the fresh concrete is overcome mathematical model. The basic Dutch model was Ac chat time, a faiIvre occurs a semi-circular founded upon the theory of viscous fluids and soils type failure! which results in a rsixing was solved using an iterative finite difference occurring at the toe of the mound Figure 97!. piocedvre. The Dutch investigators noted an This failvre can occur after only a small volume important limitation in their approach which of concrete has been placed and must be tolerated, must be kept in mind: "Although the calculated The Committee explains results appear reliable, their value must not be overrated. To treat fresh concr'ete as a viscous "In the mixing zone the concrete, so long fluid in svch calculations is a rough approxi- as it has not stiffened, will be able to rsation." coalesce. With sufficient concreting capacity to maintain an adequate rate of The parameters of the basic flow model were feed ic will be possible to ensure that following: this will happen." the cofferdam is circular, with a diamecer 5. The COmmittee uSed its findingS On tremie of 5.30 m 7.4 ft!; at the start of the cal- concrete flow ta develop a model which relates culations a layer of concrete is assumed to pipe spacing and production rates for a square be already present in the cofferdam; the placement. This madel is examined in detail thickness of this even and horirontal layer in section 6,3.1, below. is H; 6, Recognizing that the initial model imposed - at the center of the cofferdam is a vertical Limitations that might not be realistic in concreting pipe with a diameter d =300 sss! sctval placements, a model without the require- 11.8 in.!; rsent that the placement be divided into squares was developed. This model uses an at the start of the calculation the pipe is advancing sloping front; and it is desex'ibed in embedded a distance h in the concrete; detail in section 6.3.2, below. the effect of the dead weight of the concrete 7. The Dutch investigators also considered the is neglected; hydrostacic balance of che tremie system to determine how much concrete would be required theviscosit~ of thefresh concrete is O. 1 rs2/ in the tremie pipe to achieve flow, This work sec, l.l fc /sec.!. is considered in section 6.3.4, below. The findings of the Dutch investigators based 8, In regard co tremie pipe embedment, the upon the use of this model are susssarized below. Dutch wrote, "It should be borne in mind, how- ever, that better surface evenness is obtained l. A movnd of concrete built up around the tremie according as the pipe immersion depth is greater." pipe similar to the mound seen in the large-scale Unfortunately, they do not explain the basis of placement tests Chapter 2!. The mound extended that statemenc. for a distance of approximately twice the embed- ment depth from the center of the tremie pipe. 6.3. Observations and discussion. The various There is nothing in the Dutch descriptions which Dutch models noted above are examined in the suggests that the mound was forrsed by vertical following sections. Additionally, sample flaw adjacent to the tremie. calculations based vpon maximum flow distances and concrete production capability are presented 2. The shape of the concrete surface was found for a typical placement. to be independent of the distance from the pipe outlet t'o the cofferdam bottom. 6.3.1. S uare lacersent model. The basic Dutch placersenc model involves a tremie placement * The model is deve Loped in terms of meters. which is divided into squares with a length of D units on a side,e The other parameters are Since the vse of the model is independent of shown in Figure 98. the units involved, only meters will be shown in the text. 118 MED LRE CE Figure 97. Dutch failure model after ref. 3!. PRODUCTIONRATE Q, m thr. SET TIHIE ~ r, hours Figure 98, Dutch square placement model. Case shown ia H< . 25 D + C! . Shearing can be expected throughout the placement after ref. 3!. 119 Based on consideration af a 1r'5 slope and shear 20 m3which is two hours production which is failures in the tae of the slope resulting in also the set time of the concrete, The workings the mixing described above, the objective of of the model are unclear during the r'emaining the model is ta reach che point ac which che 2.8 hours of che placement since the concrete at pipe embedment becomes equal to 0. 25 D by the the surface has set, The Dutch report does time the set time of the concrete is reached. no t cons ide r t h i s pr'ob lcm. If that depth of embedment is not reached before the sec time is exceeded, the concrete would not Disregarding the above short coming, the two be able to remix and coalesce when the shear equations for determining placement rate may be failures occur. Once the embedment exceeds rewritten ta solve for pipe spacing given avail- 0. 25 D, the toe af the slope will theoretically able production capacity. Using this approach, be outside the placement area and no further the curves shown in Figure 99 were developed. shear failureS may be eXpected ta OCCur. The curves are used as follows. 'With a place- ment capacity of 75 m3/hr, a seal thickness Two cases may exist for the variables describ- af 2.0 m, and a set cirne of 2 hours, what is the ing the thickness and size of the concrete maximum allowable pipe spacing? The answer, placement. Each case leads co a different from the curves is 8,6 m. Using these curves required placemenL raLe. leads ta pipe spacings which are generally well above those recanmrended in the literature. Case I: H ,25 0 + C!m-" The failure of the model to consider place- Q = D2H/c m3/hr rnenc time after the set time of the cancrere leads to the same curve being developed for all Case II: H > ,25 D + C! placements above a critical thickness for each set time, where Hcric 0.25 D + C. Once Q = D .25 D + C!/r m /hr this critical thickness is exceeded, pipe spac- ing becomes fixed for a given production rate. Consider the fa'llowing two examples.. For example, given s placement capacity of 75 m3/hr and a set time of 3 hrs, the maximum Ex, 1.0=40m recommended spacing for all placements 3 m or C =0.25UI more in thickness is 9.3 m. Hovever, Her it 2.0 hrs ~ 0.25 9.3! + 0.25 ~ 2.6 m, which means that H = l. 0 meter no such placements would be completed before the initial concrete placed has set. To overcome Volume required = l6 m this problem, placements which are thicker than Hcric spparentiy must be divided into squares H err,25 D+ c small enough to be completed within the set time af che concrete, 6 very thick placement, there- Q ~ D2 H/t fore, would require sub-division into many smaller placement s. = 8 m3/hr 6.3,2, Advancin slo e lacement model. Realiz- Shear failures can be expected to occur through- ing that it will not always be practical to out the placement, However, the placement vill divide a crernie placement into the squares re- be completed ac the same time the first concrete quired for the above model, the Dutch investiga- placed reaches its sec. tors modified their model to use an advancing, slopinF, front edge. The geometry af this model Ex. 2. Same conditions except is shown in Figure 100. The model requires the concrete shown as cross-hatched be placed with H = 3,0 m the tr ernie in the location shown. Then, che tremie will be moved toward the far end of the Volume required = 48 m3 placemest co place the next increment of con- crete, H > 0.25 D + C The same requirement that no shear failures occur Q = D .25 D + 0.25!/t after the time chat it takes far the concrete to set is also imposed: "This can be satisfied l0 rn3/hr by choosing the rate of placing at least sa high that the concrete which at first is at the top Time of placement = 4. 8 hours. af the slope will, on completion of the con- creting, have arrived ac che final surface of Shearing will take place until the concrete the concrete." Thus, the required production reaches a depth of h s 0,25 D + 0.25, h rate becomes equal to the volume to be placed 1.25 m!. This depth requires a placement of divided by the set time of che concrete. Using the notation shovn on Figure 100, the required placement raLe becomes: Q = H2 x width!/t rn3/hr Consider che following examples: * Variables are defined in Figure 98. 120 I50 125 I 00 I- CJ Q. 75 ttj X UJ 50 G. 25 7 8 IO TREMIE SPACING, m. Figure 99. Placement curves derived from Dutch square placement model. SHADED AREA ' 5H g SHADED VOEUME=5H x WIDTH Figure 100. Dutch advancing slope placement model after Ref. 3!. Kx. 1. A tremie seal is t.o be 15 x 30 m in pIan The Dutch model was developed using these con- and 4 m thick. The set time of the concrete is siderationa: 3 hrs. Q = 400 m3/hr l. The depth of embedment of the tremie is h. 2, The height of water above the concrete surface is z. Ex. 2. A tremie seal is to be 26 x 43 m in p1an and 9 m thick approximate dixsensions of Pier 12 3. The ratio of unit weights of concrete and of the I-205 Bridge described in Chapter 3!. water is y, which is approximately 2,4. The set time of the concrete is 3 hrs. 4. The height of concrete necessary to over- Q = 2160 m3/hr come internal concrete 1'riction is twice the embedment depth, 2h. Obviously, such production rates are beyond those normally available. 5. Approximately 10 pex'cent additional height of concrete is required to overcome the friction 6.3.3. Summer of Dutch lacement models. The between the concrete and the trexsie pipe. Dutch Coasaxttee susmarized its work on these two placement models in the following statements: Therefore, the level of concrete required above the mouth of the tremie for flow to "If high quality of the concrete is required occur wil! be: and the slab to be constructed is of con- siderable thickness, it may be advisable to concrete it in individual bays. This Lc 1.1 h + 2h + z/y! will, of couxse, necessitate extra arrange- ments. This equation xsaybe solved for various values of z and an assumedembedment depth of 3 ft "If the cofferdam is not subdivided into .0 m! as is shown below. Also shown is the bays, the concrete obtained is likely to height of concrete required above the tremie be of somewhat poorer quality unless the mouth to achieve a hydrostatically balanced concreting capacity is high enough to condition, neglecting internal friction. compensate for this. In the Committee's investigations on core specimens it was found that the tremie methods produced z, ft m! Lc, ft m! Balance, ft m! relatively homogeneousconcrete possessing high compressive strength. Yet the 10 . 0! 14.5 ,4! 7.2 .2! concreting capacity used on the jobs 20 .1! 19.1 .8! 11.3 ,4! inspected was substantially lover than 30 9.1! 23.7 .2! 15.5 .7! the theoretically required capacity. 40 2.2! 28.2 8.6! 19.6 ,0! 50 5.2! 32.8 0,0! 23.8 .3! "From this it can be inferred that a sub- Limited measurements made at actual massive division into bays or a very high concret- placements have shown that the concrete returns ing capacity appear necessary only in very nearly to the balanced condition whenevex. cases vhere very stringent demands are there is a break in the placements, Additional applied to homogeneity," work performed at Wolf Creek Dam x'ef. 30! involved numerous measurements in the confined The Committee further stated, "In practice the placements. In those placements the concrete concreting schemewi11 be drawn up, suited to also returned very closely to the balanced the available capacity.u This statement condition. Thus it appears that the Dutch identifies the greatest shortcoming of the model some~hat over estimates the friction models. which resists flow, The two models do provide additional general in- The Dutch model xsay be rearranged and used to sight into the flow of tremie concrete. Perhaps solve for the depth of embedmentnecessary to their most practical use is to serve as a control concrete flow. Based upon recoasaenda- starting point for calculations of the nature of tions found in much of the 1.iterature that the those shown in section 6.3.5, below. The use- tremie hopper be kept full of concrete during fulness of the models for determining pipe spec- the placement, assume that a concrete level 2 ing or required placement rates appears to be ft .6 m! above the water surface is desired. limited. The values below are obtained: 6,3.4, Dutch h drostatic balance model. Another area covered by the Dutch investigators was the z, ft m! h, ft m! hydrostatic balance of the tx'ernie system this balance was described earlier in Chapter 4 and 20 ,1! 5.6 .7! the geometry was shown in Figure 85!. It is 40 2.2! 10.3 .1! not cleax' if the Dutch balance model was 6C 8.3! 15.3 .6! also based on the viscous fluid calculations used to develop the two flow models. Obviously, in a massive placement such embedment depths would be impractical without very high placement rates. These calculations and the of rise of Che concrete may be caLculated. hydrostatic balance measurements made certainly These values are shown in Table 29. question the feasibility of controlling the flow of tremie concrete solely by ad justing the 4. Susssary. These calculations offer a rough embedment depth of the tremie pipe. approximation of an acCual tremie placement. While reasonable flow distances have been 6,3,5. Exam le lacement calculations. The achieved, the practical problem of delivering basic scheme suggested by the Dutch models, but concrete to ten tremies has been raised. Also, without the restriction Chat the first concrete once all ten rremies are in use, the rate of placed must remain alive throughout the placement, rise becomes slow enough thaC there is a danger may be used to relate the factors of pipe spac- of the concrete setting stound the tremie if ing, concrete flow distance, and planC produc- embedment depths are not closely monitored. tion rate, The calculations in the example below represent the considerations which should The solution to these problems appears to have be included in a pre-placement evaluation, three parts: 1. Situation A ttemie-placed seal which is to tolerate greater flow distances. be 60 x 150 fC 8.3 x 45.7 m! in plan and 42 ft 2.8 m! thick. Total volume required is use a retarder in the concrete to allow for 14,000yd3 0,700 m3!, Concreteproduction a sLower rate of rise. capacity is L50 yd3/hr 15 m /hr! leading to an anticipated placement duration of 94 hrs, examine the possibility of adding additional concrete production capacity. 2. Tzemie locations and spacing. Both fixed pipe locations and advancing s!ope techniques ~6.4. S th L 11 g t * are to be considered, Figure l01 shows the this portion of the project; geometry and notation involved, 1. The recosssendations found in the literature a, Fixed locations. All tremies will be started for pipe spacing and rate of concrete place- simultaneously and will remain in their original ment appear to be very conservative and difficult locations for the duration of Che placement. to achieve in actual massive placements. b, Advancing slope. Tremies st one end of the 2, The flow models, based on viscous flow placement will be started initially. Additional theory, which were examined do not appear to tremies will be started once a predeterminted offer potential for determining optimum pipe embedment depth is reached. This approach spacing and required production rates, The requires calculation of longitudinal flow dis- models do provide a starting point for examining tance when each new tremie is started as is the variables involved using a simplified shown in Figure 102. approach. Data showing concrete flow distances for various 3, An example of simplified calculations examining numbers of tremies in the Cwo placement methods tremie spacing and concrete production rates are given in Table 27. This data may be evalu- for a typical seal was presented. Such calculations ated by selecting the single row of tremies in offer a good approximation of actual placement the fixed locations as a base against which the conditions with enough accuracy for pre-construc- other cases may be compared. This comparison tion planning, is shown in Table 2S, The use of a single row of tremies started simultaneously appears to offer favorable maximum flow distances with a minimun number of tremies. However, it must be remembered that the apparent maximum for the sloping front technique exists only until the next row of tremies is started. Then, the maximum flow reverts to the diagonal distance for the number of tremies involved. Additionally, the problem of laitance accumula- tion should be considered. Placements involving simulataneous starting of Cremies offer the potential for laitance accumulation at all intersecting faces of concrete. The advancing slope technique forces laitance toward Che end wall where it may be collected and removed. 3. Volume considerations. Assume that the advancing slope technique with five pairs of tremies is selected. Using the geometry shown earlier in Figure 102, the volume of concrete in place when each new row of tremies is started, the time when each row is started, and the rate a. GEOMETRYFOR SINGLEROW OF TREMIES FLAN!. THREE TREMIESSHOWN. b. GEOMETRYFOR OOUBLEROW OF TREMIESIPLAN!. TWO ROWSQF THREE TREMIESSHOWN. Figure 101. Geometry and notation for example spacing calculations. IIotation remains the same as additional tremies are added. IZ laI al CP sOZ aQ aId OEPTH OFEMBEOklENT~ REQUIRED TO STARTNEXT TREMIE f ~ CONCRETEFLOW OISTANCF. BEYOND PIPE WHEN4 IS ACHIKVKO ~ < HORIZONTALCOMPONKNT OF SLOPK f ~ ds Figure 102. Geometry and notation of advancing slope technique elevation!. Concrete ui 11 floe 2x + f vhen each tremie after the first is starred. 124 TABLB 27 CALCULATBD FLOW DISTANCBS* Case I Sin le Row of Tremies Started Simultaneousl Plow distances, ft m! No ~ of Tremies 75.0 2.9! 30.0 9.1! 80.8 4.6! .123 37.5 1.4! all! 48.0 4.6! 25.0 7.6! 39.1 1.9! 18.8 5 7! 35.4 0.8! 46 5 15.0 4.6! 33.5 0.2! 12.5 3.8! 32.5 9.9! Case II Double Row of Tremies Started Simultaneousl Plow distances, ft m! No. of Tremies 2 75.0 2.9! 15 . 6! 76.5 3.3! 37.5 1.4! all! 40.4 2.3! 468 25,0 7.6! 29.2 8.9! 18.8 5.7! 24.1 7.3! 10 15.0 4,6! 21.2 6.5> 12 12.5 3. 8! 19.5 5.9! Case III Sin le Row of Tremies Advancin Slo e Techni ue Slope of concrete 1:6 Depth when next tremie is started 2 ft .6 m! Flow distances, ft m! No. of Tremies 2x+ f 48.0 4.6! 87.0 6.5! 39.1 1.9! 62.0 $.9! 35.4 0.8! 49.6 5.1! 33.5 0 ' 2! 42. 0 2. 8! 32.5 9.9! 37.0 1.3! Case IV Double Row of Tremies Advancin Slo e Techni ue Same constraints as Case III Plow distances, ft m! No. of Tremies 2x+ f 40. 4 2. 3! 87.0 6 5! 48 6 29.2 8,9! 62.0 8.9! 24.1 7.3! 49.6 5.1> 10 21.2 6.5! 42.0 2.$! 12 19.5 5.9! 37.0 1.3! * See Pigures 101 and 102 for notation used. 125 TABLE 28 COMPARISON OF PLACEMENT ALTERNATIVES Needed to Better Case I Case I Case II Case III Case IV No. No. No. No. Maximum Maxi,mum Kmimum Nominal Maximum Nominal af of of of flow flow f low flowe flow f lowe Trem- Trem- Trem- Trem- ft m! ft m! ft m! ft m! ft m! ft m! ies ies ies ies 48. 0 4.6! 4 40.4 2.3! 5 42.0 2.8! 33.5 0.2! 10 42. 0 2.8! 21. 2 . 5! 39.1 1.9! 6 29.2 8.9! 6 37. 0 1. 3! 32. 5 9. 9! 12 37.0 1.3! 19.5 .9! 35.4 0.8! 6 29 ' 2 8.9! >6 >12 * Nominal flow ~ maximum flaw distance once next row of tremies is started. TABLE 29 - ESTIMATED PLACEMENT COHDITIONS* +Values derived from geometry previously shown. Assumptions: Concrete is level across short dimension of seal; slope in long dimension is 1:6; production rate is 150 yd3/hour 15 m3/hour!; production is evenly distributed among tremies in use. eeTheoretical rate of rise based on production capability and size of seal. 1 '76 CHAPTERI searchere see Chapter 2! mey have resulted fram differences in the concrete mixtures CONCLUSIONSAND RKCONNENDATIONS tested rathex' than fram observations of differ- ent flow mechanisms. As far as ie known, the 7.1 S ecific conclusions. The conclusions rale that the concrete mixture plays in the flow presented in this section relate to the stated pattern of tremie-placed concrete hss not been objectives in the six areas of this investiga- reported previously. tion. These conclusions are presented in the sametopic sequence as are the chapters of 5. The configuration of the surface of tremie- this report. placed concrete appears to be a function of the type of flaw which occurred when the concrete 1. For the concrete characteristics evaluated wes placed. For the first type of flow de- using a eeriee of standard and non-standard scribed expanded bulb!, surfaces were very tests, a traditional tremie concrete mixture flat and there was essentially na wounding at wae significantly outperformed. Concrete the tremie location. Fox the second type of mixtures containing potzolanic replacements of flow upward and over!, surfaces were much significant amountsof the cement up to 50 rougher and s significant mound developed at percent! or containing entrained air were the the tremie location. best overall performers. 6. The density of tremie-placed concrete de- 2. Development and selection of a concrete creased with distance from the tremie pipe. mixture far placexxent by tremie should be based Although these decx'eases were very small for upon more information than is available fram the resultant sound portions of concrete, the standard slump test. Three of the non- significant reductions were observed when standard tests evaluated, the tremie flow test laitance was included in the calculations. and Che two segregation sueceptibiliCy teste, This reduction in unit weight cauld have serious appear to have potential fox' further uee in consequencesin a seal. placement in which the evaluating tremie concrete mixtures. Finally, weight of the concrete is necessary to offset the slump loss tesC, conducted using the uplift forces. Therefore, a conservative standard slump test, should be included in the approach in evaluating required seal thickness testing program . is indicated. 3. AddiCives which lead to thixotx'opic con- 7. The observations of the colloidal layer at cxetes appesx'to offer no advantagesfor uee in the beginning of the placements reemphasize massive tx'ernie placemente. Such concretes have the requirement for care in starting, handling, poor flow characteristics, are extremely diffi- snd restarting concrete flow through tremie cult to restart flowing after e break, and offer pipes. In particular, when a tremie pipe is problees of manufacture and control during field moved, care should be taken to restart con- use. Thixotropic additives may be af benefit crete flow slowly in order to minimize formation in other types of underwater placemente such as af such a layer and the subsequentwashing af very small volume ar thin sections ar in place- the concrete already in place. ments subjected to floving water. 8. Reinforcing steel was secux'elyembedded by 4, The flow pattern of tremie-placed concrete tremie-placed concrete in the laboratory tests. is extremely caxxplex xxuch more so than is Rowevex', as has been shown, even the presence normally described in the literature. The of well-epaced bare vill impede the concrete flow pattern ee seen in these teste does not flov to same extent. These tests have reempha- appear to be that of a simple injection into a sized the need for care in detailing reinfor- mass of previously placed concrete. Instead, cing steel for tremie concrete plscements to the process appears ta be as follows: Concrete insure adequate clear space for flav between leaving the tremie forms a bulb around the bars. mouth of the pipe. The size and nature of this bulb appear to depend upon the nature and con- The possibility of embedxxent of the reinforcing sistency of the cancreCe mixture. For concretee steel in laitance rather than concrete as oc- vith law shear resistance, the bulb simply curred in Tests 1 and 2! must be kept in mind. expands and for~es previously placed concrete Positive measures must be talxen to insure that x'adially away fram the tremie pipe. For a con- sound concrete reaches and surrounds the steel, crete mixture vhich is stiffer, the bulb tends parCicularly if bars are near the extremities to be quite constricted. In this csee, initia! of the concrete flow pattern. flow takes place vertically adjacent to the tremie pipe, After flowing upward, this con- 9. Even in carefully controlled laboratory crete then flavs outward over the concreCe placemente, varying amounts of laitance vere placed earlier rather than pushing it away from formed. Planning for the rexaovsl of this lait- the tremie pipe. In both modes of flow the ence ~durin placement is a necessity, particu- resultant concrete can be of high quality and larly for reinforced tremie concrete structural elements, Monitoring of concrete surface eleva- homogeneity. tions during placement should be done to iden- It appears that the differing deecriptione of tify any low areas in which laitsnce may be Cremie concrete flow presented by other re- trapped. Suitable equipment eir lifts or 127 pumps! must be available for use in any Low combination of thin seams of laitance and areas that may develop during a placement. thermally-induced cracks in the concrete. 10. The presence of substantial amounts of 17. The concrete placed for the Pier 12 seal pozzolan up to 50 percent by weight! in the contained a fly ash replacement in order to concrete pLaced by tremie in the large scale reduce temperatures. This concrete performed laboratory tests seemed to have no detrimental well and no problems were attributed to the effects on the nature of the product of the presence of the fly ash, placement. The use of substantial proportions of pozzolsn offers potential economy and reduc- Lg. The mounds seen on the surface of the seal tion in thermal strains, but may require a were very similar to those seen in the labora- longer curing period in order to gain adequate tory placements. The same flow mechanism may strength, have been responsible for both cases of mound- ing. The sounding data do not provide sufficient 11. The presence of a water reducing and retard- information to determine the precise flow mech- ing admixture had a significant beneficial anism which occurred during the Pier 12 seal effect on the tremie-placed concrete -- surface placement. slopes were flatter, the mound at the tremie location was eliminated, and laitance was 19. The examination of the Wo1f Creek place- reduced. This effect is believed to be due to ment revealed generally high quality concreted s reduction in the shear resistance in the fresh Some minor nonhomogeneities snd laitance were concrete which allowed a more favorable flow found in the primary elements. There appears pattern to develop. This beneficial effect was to be no procedural step which could be easily not seen with all types of water reducing and changed and which would clear up the scattered retarding admixtures which were tested. problems found in these prisiary elements, The concrete was apparently segregating while flow- 12. The work on Pier 12 of the 1-205 Bridge ing down the tremie pipe itself. Due to a showed that temperatures within the general combination of several factors listed below!, mass of the tremie concrete may be evaluated there was not adequate remixing to overcome with reasonable accuracy using s simple itera- the initial segi'egation. The factors believed tive method. However, this method is subject to have been responsible are: to serious limitations in providing tempers- ture predictions for concrete at and near the a. The small cross-sectional area of the primary outside surfaces of the placement. e92.ements; 13, The temperatures measured in the critical b. The smooth walls of the primary elements; outside areas of the Pier 12 seal showed that steep thermal gradients develop. Since precise c. The rapid rate of placement in the primary information on the early age characteristics elements, of the concrete was not obtained, it is not possible to state with certainty that thermally- 20. Measurements taken inside and outside the induced cracking did occui. However, the tem- tremie pipe at Wolf Creek indicated that the perature gradients observed were within the placement system was nearly at balance whenever range of values which could cause such cracking. the placement was stopped, with the exception of a few anomalies. The significance of these 14. Acceptable quality concrete was found at the anomalies is not understood. The return of the extremes of the seal of Pier 12 after flowing tremie system to a hydrostatically balanced state approximately 70 ft 1 m!. This flow distance indicates that earlier concepts recommending Xs much greater than that normally recommended the control of flow by means of pipe embedment in the existing literature for tremie-placed depth msy not be correct or may require embed- concrete. ment lengths too great to be practical, partic- ularly for small volume placements, 15. An area in the seal concrete was seen to have abnormally low temperature development 21. With the exception of the few scattered during the placement. This area was later anomalies found in the primary elements, high found to contain poorly cemented and uncemented quality concrete was successfully placed by materials. This same area appeared as an anom- tremie at Wolf Creek in very deep 78 ft 85 m!! aly in the placement cross sections developed confined elements. Given adequate conditions to by soundings although not striking enough to allow remixing and a properly designed concrete cause concern during the placement!. This in- mixture, there is no reason to believe that dicates that temperature snd sounding data can tremie placement depths could not be extended. be used ss indicators of locations of possible anomalies and thus suggest locations for cor- 22. There is no reason to expect that the Wolf ing in order to verify quality of tremie con- Creek cutoff wall should not perform in a crete. satisfactory manner since the primary elements were encased in permanent steel pipes. However, 16. Water flow was seen in core holes which did the use of very small diameter, uncased elements not penetrate the full thickness of the seal. for cutoff walls, as used in some previous dam This flow is believed to have been due to a rehabilitation and improvement projects, does not appear to insure a complete cutoff. 128 23. The concrete mixture which contained a fly 3. The development of high temperatures from ash replacement of a portion of the cement! used hydration of cement within concrete placed by at Wolf Creek was cohesive and flowed well, The tremie must be taken into account as would be inclusion of fly ash in this tremie concrete done for any other mass concrete placement. mixture had no apparent detrimental effects. Due to the typically rich concrete mixtures used and the inaccessible placement locations, temper- 24. An accurate prediction of temperatures ature problems are potentially more serious for within a tremie seal including areas near a tremie placement than for other mass place- the concrete surfaces! can be obtained using a ments. Adequate techniques are available ta finite-element approach. The program which predict temperature distributions within tremie- was developed allows the significant variables placed concrete. in a tremie placement to be changed easily for input to an existing finite-element program, 4. The three items mentioned above lead to an Use of this technique will allow for more increased understanding of the required charac- accurate and complete evaluation of thermal teristics for a concrete mixture which will be considerations for massive underwater place used in a massive tremie placement. The concrete ments than has been the case to date. must resist segregation during what may be a significant fall in the tremie pipe; it must flow 25. The flow models which were examined were readily to provide for adequate remixing and to derived from viscous flow theory. Their useful- provide a flat surface; and it must not generate ness for direct predictions concerning tremie excessive amounts of heat. A fourt'h require- pipe spacing and placement rates appears to ment, the ability to resist washing out of cement be very limited. However, the models do pro- from the concrete may not be as significant as vide a good starting point for an analysis of is traditionally believed, particularly if the these variables. concrete is designed to develop the expanding bulb type of flow pattern. Additionally, a 26. Simple calculations which consider the concrete which resists segregation will in- variables involved in s tremie placement appear herently resist loss of cement. to offer an acceptably accurate evaluation for construction purposes. Such calculations are S. Unfortunately, with the exception of the easily performed and will highlight areas heat generation requirement, measurement of which should be mare closely examined-- these desired concrete characteristics cannot be excessive flow distances or low placement made using standardized procedures. It is clear rates. Once such areas have been identified, that the slump test must be supplemented by non- they must be resolved to the satisfaction of standard tests during mixture development. As all parties involved in the placement. a final step, large-scale placements similar to those in Chapter 2 but nat necessarily as 27. In most cases, the critical factor in a complex! are recommended prior to actual use of massive tremie placement will be the concrete a concrete mixture. Once the mixture has been production capacity available. Use of a pro- developed and verified, the standard tests should perly proportioned concrete mixture will do as be adequate for production control. much as any other factor ta offset production limitations. 6. A "good" tremie concrete has traditionally been characterized as being cohesive yet posses- 7. 2. General conclusions. The following con- sing good flow characteristics. Unfortunately, clusions are of a more general nature or were neither of these qualities are readily measur- developed from the interrelationships of the able! These characteristics are usually achieved various portions of this project: by means of a high cement content, high per- centage of fine aggregate, and a low water-cement 1. Testing dane during this project indicates ratio. Both the small- and large-scale tests that the flowability characteristics of the showed that the traditional tremie concrete mix- concrete are extremely important, These ture can be improved upon. These improvements characteristics determine the nature of the include replacement of a portion of the cement flow pattern which the concrete exhibits after with a natural pozzolan or fly ash, use of en- leaving the tremie pipe which in turn determines trained air, and use of a water reducing and the sur face characteristics of the concrete retarding admixture. Concrete mixtures which placement. followed the traditional "recipe" but which in addition possessed increased flowability due to 2. measurements taken inside and outside the the addition of a water reducing and retarding tremie pipe during placements have revealed admixture performed bette» in the large-scale that concrete being placed by tremie does not laboratory test placements. This confirms flow gently down the pipe. Instead, it msy fall reports from field placements conducted over a significant distances inside the pipe resulting number of years. However, note that. improve- in segregation. This segregation is generally ments in flowability were not seen with all overcome provided there is adequate space and types of water reducing and retarding admixtures roughness within the placement area to allow which were tested. remixing to occur. Care is recommended for any placement in which there may be factors which 7. The significance of possible thermally-induced cauld inhibit this necessary remixing. cracking in tremie-placed concrete is a function 129 of the role of the concrete. In a massive coffer- embedment depth and flatness of the concrete dam seal, 1.irni ted cracking may be acceptable and surface was found, The work done in che large- extensive precautions may not be necessary. For scale tests suggests that very flat surfaces can a reinforced structural tremie placement, the be achieved if the proper concrete mixture is possibility of thermally-induced cracking may used. Proper embedment may be more important for require additional temperature control measures. maintaining the tremie seal than Ear surface The degree of restraint must also be considered slope control, when evaluating the potential for cracking. Tre- mie plecemente may range from essentially un- 13. Tremie concrete was success fully placed in restrained conditions such as in a seal on a a massive seal 9700 yd 400 rn ! and in deep eo f t found at ion, to highly res trained cond it iona confined elements 78 ft 85 rn!! during the if the tremie concrete is placed on rock or on projects observed while preparing this report. previously placed concrete. I E deemed necessary, At first glance it may seem that the mechanisms the techniques for controlling temperature and phenomena identified herein may only serve development in mess concrete placed above water ta add additional restraints and ccnnplexity to as described by Garison, Houghton, and Polivka an already complex process. However, it is the ref. 34! may be applied, with some exceptions, hope of the authors that the identification and co tremie-placed concrete. examination of these areas will serve to insure greater reliability in future applications of g. Of che available techniques for controlling underwater concrete placement technalagy. temperatures within mess concrete, perhaps the most readily adaptable to tremie concrete is the 14. The work done in this research project has replacement af a portion of the cement with a shown that high quality concrete, ecruccural paznolanic mater'ial, Hone of the field place- and nonstructural, can be placed under vater by ments covered by this report showed any detri- tremie methods. This work is believed to make mental effects due to a concrete containing a a significant contribution to improve practice panxolan being placed by tremie, Additionally, and results. concrete mixcures containing ponsolan replace- ments were among the outstanding performers in 7.3. Recommended ractice. Following is a the small- and large-scale laboratory tests. recommended practice for massive tremie place- ments. This recanenended practice is intended 9. Recanrmendationsfrom the literature on pipe ta serve as a planning tool and to amplify the spacing and placement rates appear to be very items included in the Guide Specification pre- conservative and extremely difficult to achieve sented in section 7.4. in massive placemente. In the placement of Pier 12 and others! concrete was allowed t:o These reconnnendations are based on the research flow much greater distances and waa placed much presented in this report, other research con- more slowly than is normally recannnended. This ducted by the authors, and upon the experience concrete turned out: to be of very high quality. of the authors on a variety of placements. Longer flow distances and slower placement rates should be allowed in specifications far massive 1. A licsbilit . This recommended practice is tremie placements. applicable to all massive tremie concrete place- ments - structural or nonstructural reinforced 10. Very accurate temperature predictions were or nonreinforced!. Typical. placements vould achieved using simple models of concrete flov. include cofferdam seals, filling of precast con- is doubtful that significant improvements in crete elements or steel forms for bridge piers, temperature predictions could be achieved by or elements of offshore structures. developing and using a more complex flow model. These reconnnendations are also generally applic- 11. Existing recannnendations concerning concrol- able to other types of tremia concrete place- ling the Elaw of concrete through a tremie by rnents such as small volume placements, thin raising and Lowering the tremie may be mislead- overlay placemente, snd deep confined placements. ing. Tbe concrete in the tremie will generally However, the special requirements of these non- come to rest st or near the hydroecacically mass plscemente must be considered in conjunction balanced condition. In most instances «ith a with these reconnnendatians. normal embedrneat depth ta 5 ft .0 to 1.5 m!, it will not be possible to keep the tremie happer 2, 8aeic cones ts. These recoennendstiona are full ae ie often recommended. To keep the tremie based on the following: hopper full, pipe embedment would have ta be deep enough to extend into concrete which is stiffen- a, The concrete is placed under water using ing, In such a case the expanding bulb type of gravity flow through a tremie pipe. flow may be prevented from occurring. Thus for deep placements, it will usually be necessary b. Appropriate steps must be taken to insure to accept a concrete leveL somewhere in the tremie that the first concrete introduced into the pipe below the hopper and to realize the potential tremie ia protected from the water until a mound for segregation which will exist, Although in of concrete has built up at the mouth of the most cases, adequate remixing will take place in tremie and a seal is established. the pipe or after exit from the pipe!. c. The mouth of the tremie pipe must be kept 12. Ho definitive reiationshfp between pips 130 embedded within the mass of fresh concrete. At Coarse Aggregate; 3/4 in. 9.0 mm! no time should concrere be allowed to fall Fine Aggregate: 45X by weight of total aggregate content directly through water. + Air Content. 5 percent 1 percent d, The tremie pipe must remain in a fixed posi- Maximumwater-cementitious material ratio: 0.45 tion horizontally at all times while concrete Admixtures: Water reducer and retarder is flowing, Horizontal distribution of the con- Slump: 6 to 7 1/2 in. 5 ta 19 cm! crete is accomplished by the flow of the concrete after exiting the tremie; by halting placement, f . Modi f ic at iona to the basic mixture . The moving the tremie, reestablishing the seal, and basic mixture may be modified as necessary de- resumingplacement; or, by the use of multiple pending upon materials availability, service tremies. conditions, temperature considerations, etc. Modifications should be made with an sim of 3. Concrete materials and mixture desi n. retaining the flow and cohesiveness of the bsszc mzxturs, s. General materials requirements. The pre- cautions normally applied to concrete materials g. Testing. 'The proposed concrete mixtures should also. be applied for materials intended should be tested using standard ASTM tests for for use in tremie-placed concrete, Cement and bleeding, time of set, air content, unit weight, porzolsns must meet appropriate specifications. slump loss, compressive strength and yield to Aggregates must be clean, sound, free of insure compatibility of components and suit- deleterious materials, snd evaluated for ability of the concrete for its intended pur- potential harmful chemical reactions. Mixing pose. water must be clean snd free of potentially harmful materials. Admixtures must meet appro- h, Final selection. Final selection of a con- priate specific'ations. All materials should be crete mixture should be based upon test place- tested to insure compatibility. ments made under water in a placement device similar to that described in Chapter 2 of this b. Cement and pozxolans. Selection of the repart or in a pit which can be dewatered appropriate type of cementsnd determination of after the placement. Test placements should the suitability of including pozxolans must be examined for concrete surface flatness, be based upon evaluation of service conditions, amount of laitance present, quality of cancrete available aggregates, heat generation, snd at the extreme flow distance of the test, and availabilities of various types of cements snd .flow around embedded items, if appropriate. pozzolsns. The acceptability of a particular poxxolen incressed workability, changes in 4, Tem erature Caneideratianz. water demand, rate of strength gain! should be verified before final selection. a. The potential temperature increase should be evaluated using a simple interative or a c. Aggregates Well rounded natural aggregates finite-element technique. Anticipated thermal are preferred due to the increased flowability gradients should also be considered of cancretes containing these aggregates. If manufacturedaggregates are used, the fine b. Sexed upon predicted concrete temperatures aggregate and cementitious materials contents and gradients and the nature of the concrete msy have to be increased to achieve satisfactory placement, s determinatian of the seriousness flowability. Aggregates should be well graded. of the predictions may be made. Limited crack- Maximum size for aggregates used in reinforced ing msy be acceptable in a nonstructural placement plscementsshould be 3/4 in. 9,0 mm!and in while 'he same degree of cracking may be un- nonreinforced placements should be 1 1/2 in. acceptable in a structural element. 8.1 mm!. Fine aggregate content should be 42 to 502 of the total aggregate weight. c. Maximus temperatures and gradients may be reduced by employing the following steps: d. Desired characteristics, Concrete for tremie placements must be cohesive and resist segrega- Use a lower hest cement. tion as well as flow readily. Nonstandard tests are available which allow evaluation of Replace increased amounts of cement with a these characteristics for comparison of con- suitable pozzolan. crete mixtures. Tremie concrete should not be proportioned on the basis of strength snd/or Lower the concrete placement temperature. slump alone. 5. Concrete manufacture. e. Basic mixture proportions. A starter mix- ture, developed to include these characteristics s. Materials handling, The same requirements found ta be beneficial in the present report, for materials storage and handling used for- is as follows: iagredients for concrete to be placed in the dry must be imposed for concretes placed Cement: 600 lb/yd 56 kg/m3! under water, Pazzolsn: 5X by weight of cementitious materials! 105 lb/yd 2 kg/m3! b. Fetching and mixing. The same requirements 131 .or accuracy in batching concrete ingredients ! Mix off site De'iver within speci fied used for concrete placed in the dry must be time or revolutions and - Tost at t.rctiie used for concrete placed under water. Control of the amounts of concret'e ingredients is one f. Concrete temperature. The maximum al]owebte of the most important inspection items avail- concrete temperature should be established able for underwater placements. The same based upon anticipated thermal conditions with- req >irements for concrete mixer performance in the placement. Depending upon the volume of used for placements in the dry must also be the placement, maximum temperatur.. s in t.he applied for placements under water. range of 60 to 90oF 6o to 32o C! have been specified. c. Testing during production Once a concrete mixture hes been approved, slump, air contenti A Ninimum conciete temperature of 40 F 5o C! unit weight., end compressive strength testing should be imposed. Normally, freezing of con- should be adequate for production control. crete placed under water will not be a problem. Because of the significance of the flowability However, the flowability of concrete at lower of the concrete t'o the success of the place- temperatures may be reduced. Because of the ment, slump end air content tests should be potential for erratic slump loss behavior, performed more frequently than is done for extreme care should be used in heating water concrete placed in the dry. A minimum testing or aggregates to raise concrete temperatures. schedule would be: 6. Placement e ui ent. Slump: every 250 yd 90 m ! Air content.' same as slump a, The tremie should be fabricated of heavy Unit weight: every 500 yds 80 m ! guage steel pipe. The pipe and all connections Compressive strength: 6 cylinders for every must be strong enough to withstand all sntic- 100t7yd3 65 ts3! pated handling stresses. Temperature: Whenever other testing is done b. The tremie should have e diameter large Compressive strength testing should be accomp- enough to insure that aggregate caused block- lished at. 7 and 28 days. Seven. day strengths ages will not occur. Pipes in the range of may be used as a basis for determining when the 8 to 12 in. diameter 0 to 30 cm! are adequate concrete has gained enough strength to allow for the range of aggregates recommend -d, dewstering the structure, c. For deep placements the tremie should be d. Sampling during production. The location fabricated in sections such that the upper f>r sampling during production and placement sections can be removed as the placement pro- vill depend upon the elapsed time between pro- gresses. Sections may be joined by flanged, duction end arrival at the tremie hopper. For bolted connections with gaskets! or may be exemple, in the placement described in Chapter screwed together. Whatever joint technique is 3 a portion of the concrete was produced in a selected »oints between tremie sections tsust floating piant at the site, Sampling at the be water-tight. The joint system selected mixer was essentially the same as sampling et should be tested for watertightness before the tremie hopper. The remainder of the con- beginning placement. Flanged connections are crete was produced off site and was trucked included in the Guide Specification.! and pumped to the tremies. For that concrete, sampling at the tremie hopper would be more d. The tremie pipe should be marked to allow appropriate. In any case, the objective is qu i ck de te rmina t ion o f the d is t anc e f rom to insure that concrete with the proper char- the surface of the water to the mouth of the acteristics is arriving at the cremies. tremie. e, Slump and eir content loss. Tests to e. The tremie should be provided with a funnel determine the slump and air loss characteris- or hopper to facilitare transfer of concrete tics of the selected mixture should be per- from the deliverv device to the tremie. formed using the type of equipment which will be used to transport the concrete from the f. A stable platform should be provi.ded to point of manufacture to the tremies. Based on support the tremie during the placement. thi= testi.ng, limits may be established on the Floating platforms are gsnerallyt not suitable. length of time between mixing and arrival at The platform should be capable of supporting thr. trcmie or on the number of revolutions of the tremie while sections are being removed the transit mixer drum, if appropriate. from the upper end of the tremie. Sp~cification provisions limiti-g elapi ed time i r drum revolutions must complement any g. A suitable power hoist should be on the prov is ious for tea t ing at the tremie hopper, tremie support platform to facilitate vertical i f inc1uded In cases of conflict, concrete tsovement of the tremie during the placement. performance provisions rather than time or Use of e crane to provide this vei't.ical adjust- revolutions should prevail. A summary of ment is not recommended. recommended testing would be as follows: h. A crane should be available to lift the .! Hix at site - Test st mixe-. entire tremie pipe in case the tremie must be moved or lifted out of the water to be resealed. 132 i. Depending upon the method selected for Initial dry pipe achieved by using a plate sealing the tremie at the beginning of the and gasket tied to the mouth of the tremie. placement see paragraph 8!, an adequate supply This method is recommendedfor most place- of end closure devices or go-devils should be ments and is included in the Guide Specifica- available. tion.!. j . Airlifts or pumpsmust be available to - Use of a go-devil to separate concrete and remove laitance and other unsuitable material water. This method can be very disruptive which accumulates in low areas during the to material beneath the mouth of the tremie placement. as the go-devil forces water out of the tremie. Due to the possibility for washing 7, Pre lacement lannin concrete in place, this method should not be used to restart tremies. If inflatable balls a. Planning for the tremie placement must begin are used as go-devils, consideration should as soon as the decision to use tremie-placed be given to the depth at which the balls will concrete is made, not. just prior to the begin- collapse due to water pressure. ning of actual placements. Items with a long lead time in the tremie process include: Use of a double pipe for deep placements in which pipe bouyancy ie a problem. This - detailing reinforcing steel if any! to mini- method involves use of a smaller diameter mize restrictions to flow. tremie within the main tremie to gain the initial seal. - detailing of forms, particularly if precast elements are to be filled with tremie con- e. An inspection plan detailing sounding loca- crete, to eliminate abrupt changes in sec- tions and frequency of soundings should be de- tions, openings, or areas in which laitance veloped. Soundings should be taken over the could accumulate or be trapped. entire area of the placement on a regular basis, such as every hour or every 200 yd3 5 m3!. - consideration of overexcavating the placement Locations for taking soundings should be marked area to preclude concrete removal if tremie- on the structure to insure that all soundings placed concrete is above design grade. are made at the same location. Additionally, soundings should be required on a more frequent - consideration of incorporating members re- basis adj scent to each tremie to monitor pipe quired to support. the tremie platforms into embedment. Data obtained from soundings should the internal bracing scheme of a cofferdam, be plotted immediately to monitor the progress if appropriate. of the placement. b. The overall placement scheme should be de- f A concrete sampling and testing plan, con- veloped considering the following items: sistent with the agency's other concrete test- ing requirements and the recommendations above Available concrete production capability. paragraph 5c! should also be developed, This plan should detail all testing and corrective - Availability and capacity of equipment for actions to be taken by the contractor to transferring concrete to the tremies. insure that concrete of the desired character- istics is delivered to the tremie. The total volume of concrete to be placed. g. A preplacement conference should be held in The various placement schemes available which all details of the placement are presented fixed tremie locations or an advancing slope. to the owner's engineer. Placement should not be allowed until the placement plan, concrete - Any restrictions to flow such as reinforcing mixture, inspection plan, and concrete sampling steel or piles which must be embedded in the plan are approved. concrete. 8. lacement rocedures. - Maximum flow distance of the concrete. Plows in the range of 30 to 70 ft 9 to 21 m! have a. All areas in which there is to be bond produced concrete of excellent quality. between steel, wood, or hardened concrete and fresh concrete should be thoroughly cleaned c. Consideration of the above items should re- iseeediately prior to beginning concrete place- sult in the development of a placement plan ment to remove mud, algae or other objection- which includes tremie pipe spacings and loca- able materials. tions throughout the duration of the placement. The plan should also include the planned loca- b. Tremiee started using a dry pipe technique tions to be used for relocating tremies as the should be filled with concrete before being placement progresses. raised off of the bottom. The tremie should then be raised a maximum of 6 in, 5 cm! to d. The method of sealing the tremies at the initiate flow. These tremies should not be beginning of the placement must be considered lifted further until a mound is established in detail. The most commontechniques are: around the mouth of the tremie pipe. Initial 133 lifting of the tremie should be done elawly example provided in Chapter 6 to minimize disturbance of material surrounding the mouth of the tremie. 1. The volume of concrete in place should be monitored throughout the placement, Undex'runs c, Tremies started using a go-devil should be are indicative of loss of tremie seal sinre the lifted a maximum of 6 in. 5 cm! to allow washed and segregated aggregates will occupy a water to escape, Concrete should be added to greater volume. Overruns are indicative of the tremie slowly to force the go-devil downward. loss of concrete from the forms. Once the go-devil reaches the mouth of the tremie, the tremie should be lifted enough to Tremies and airlifts should be relocated as allow the go-devil to escape. After that, a governed by soundings and the placement plan. tremie shovld not be lifted again until a Tremies which are relocated should be resealed sufficient mound is established around the in secor'dance with the procedures given above. mouth of the tremie. n. Tremie blockages which occur during place- d. Concrete supply to a tremie at the beginning ment should be cleared extremely carefully to of a placement should be uninterrupted until a prevent loss of seal. If a blockage occurs, mound sufficient to seal the tremie has been the tremie should be quickly raised in. to established. 2 ft 5 to 61 cm! ! and then lowered in an attempt to dislodge the blackie. The depth e. Tremiea should be embedded in the fresh con- of pipe embedmentmust be cia!sly monitared crete from 3 to 5 ft ,0 to 1,5 m!. Exact during all such attempts. If the blockage embedment depths should depend upon placement cannot be cleared readily, the tremie should rates and set times of the concrete, be removed, cleared, resealed, and restarted. f. Tremies shall not be moved horizontally o. Soundings should be taken as specified in while placing concrete. the inspection plan, g. All vertical movements af the tremie pipe p. Cancrete samples should be tested in accord- must be done slowly and carefully to prevent ance with the concrete saxapling plan. loss of seal, 9. Poet- lacement evaluation. h. If loss of seal occurs in the tremie, place- ment through that tremie must be halted imsedi- a. Coring should be conducted in areas of ately, The tremie must be removed, the end maximumconcrete flora or in areas of suspect plate must be replaced, and flow must be re- concrete quality. started as described above. To prevent wash- ing of concrete in place, a go-devil should b. After dewatering, the surface of the con- not be used to restart a tremie after loss of crete should be accurately surveyed to evalu- seal. ate the adequacy of the concx'ete mixture and the placement plan. i. Concrete placement should be as continuous as possible through each tremie. Excessive c. After removal of forms or sheet piling, the breaks in placement may allow the concrete to exterior svrface of the concrete should be stiffen and resist restarting of flow once inspected by divers for evidence of cracking, placement reaumea. Interruptions of placement voids, honeycomb, etc. of up to approximately 30 minutes should allow restarting without any special procedures, 7.4 Guide s ecification. The following specifi- Interruptions o f between 30 minutes and the cation is based upon the recommendedpractice initial set time of the concrete should be presented above. This specification is intended treated by x'emoving, resealing, and restarting for massive placements such ae for bridge piers the tremie. Interruptions of a duration greater or major offshore construction. The guide than the initial eet time of the concrete should specification was prepared based upon the follow- be tieated as a construction joint as discussed ing aseumptiona: below. 1. The using agency has its own specifications j. If a bxcak in placement results in a planned covering concrete materials akd manvfacture. or unplanned! horizontal construction joint, the concrete surface should be "green-cut" after 2. This guide specification vill be part of a it sets. The concrete surface should be jetted 1srger project specification; it is not intended iaxaediately prior ta resuming concrete place- to stand alone. ment, 3, The contractor will be responsible for quality k. The rate of placement should be ae high as contro1 testing ee speci fied by the owner. the production capacity allows. Representative rates of concrete rise range upward from 4. The term "Contracting Officer" has been used 0.5 ft/hr .2 m/hr!. These values should be to denote the owner's representative. This term calculated by dividing tbe er,tire placement should be replaced by "Resident Engineer" as axes by the plant capacity, ae wes done in the appx'opriate. 134 Underwater Mass Concrete Tremie Concrete! NOTE: If gravel is unavailable, suitable work- ability will normally require higher sand per- 1.1 General centagesup to 50X and additional cementitious material! Pine Aggregate: 42-50 percent by weight of total 1.1.1. Underwater mass concrete in bid item aggregate, shall be placed by the tremie process. Air Content: 5 percent - 1 percent Maximum Water-Cementitious Material Ratio: 0.45 1.1.2. The contractor shall conduct a preplace- Slump: 6 to 7 in. 5 to 19 cm! ment conference to review all details of the Admixtures; Water Reducer and retarder. concrete rsixture proportions, tremie equipment, placementprocedure plan, concrete samplingand 1.3.2 Final approval of a concrete mixture testing plan, and inspection plan. developed by the contractor shall be based on concrete performance in a large-scale flow test 1,1.3. No underwater placements shell be made in which a minimum of 10 yd 8 m ! shall be until all concrete materials, concrete mixture placed per test. Concrete for these tests shall proportions, tremie equipment, placement pro- be placed in s water-filled box or pit using the cedure plan, concrete sampling and testing plan, tremie equipment and procedure proposed for the and inspection plan are approved by the Con- project. The water temperature shall be close tracting Officer. to that anticipated in the actual field place- ment. 1.2. Materials 1.4, Concrete Nanufscture 1.2.1. All materials for underwater mass con- crete shall meet the requirements for materials 1.4.1 All materials for concrete placed under for concrete placed in the dry as specified in water shall be stored in accordance with the section of these specifications. The requirements for materials for concrete placed following additional requirements shall also in the dry as specified in section of apply: these specifications. a. Cersenc shall be Type I or II meeting the 1.4.2. All bstching, rsixing, and transporting requirements of ASTNC 150. NOTEr The option- equipment for concrete placed under water shall al heat of hydration requirement of ASTNC 150 meet the requirements for batching, mixing and shall be invoked if calculations indicate transporting equipment for concrete placed in thermal problems.! the dry as specified in section of these specifications. b. Chemical admixtures governed by ASTMC 494 shall be tested in conjunction with the air- 1.4.3. The method s! of transporting concrete entraining, admixture and cement proposed for use to be placed under water from the point of on the project to insure compatibility. manufacture to the tremie hopper shall ensure delivery without segregation or excessive delay, 1.2.2. The following weights and volumes of proposed concrece rsaterials shall be provided 1.4,4, Concrete to be placed under water shall to the Contracting Officer for approval and have a minimurs temperature of 40 F 5 C! and mixture proportioning! no later than days a maximumtemperature of oF. NOTE, prior to the beginning of placements. Maximum tersperature should normally be between 60o to 90oF 6 to 32oC! and should be deter- Coarse Aggregate NOTE: Speci fy requ ired mined on the basis of anticipated thermal Fine Aggregate rieights and volumes,! problems. Cement Pozzolan if any! 1.4.5. Concrete to be placed under vater shall Admixture s arrive at the tremie hopper no later than Water minutes after discharge from the mixer! a f ter no more than revolutions of the 1.3. Concrete ro ortions transit mixer drum!.~NOTE: These limits should be established by slump and sir content 1. 3. 1. Concrete proportions shall be providerl loss testing.! NOTE: The provisions of this by the contractor provided by the Contracting section must agree with those of section 1.5.4. Officer!, The following mixture shall be used for bidding purposes: 1.5. Sam lin snd Testin Re uirements Cement; 705 1b/yd 56 kg/m !, Type I or II. 1.5.1. The contractor shall develop a concrete Pozzolan: If required or permitted, replace up sampling and testing plan which shall include to 15X by weight of cersent with an equal weight the testing shown in Table 1.1. This plan of pozzolan rseeting the requirements of ASTMC shall be submitted to the Contracting Officer 618, Glass F or N, days prior to beginning placement. Coarse Aggregate: 3/4 in. 9.0 mm! maximum for reinforced placemerrt; 1 1/2 in. 8.1 mm! 1.5.2. The contractor shall be responsible msxirsum for unreinforced plscements. for conducting all testing on the sampling and Gravel aggregate rounded! shall be used. testing approved plan, 135 TABLE 1. ! MINIMUM TESTING REQUIREMENTS Pre quency At Tremie Tes c S tandard 1 Tes t for each: At Mixer ~Ho er Slump ASTM C 143 250 yd3 6-7.5 in. 6-7 in. 5-18 cm! 90 m3! 5-19 cm! Air Content ASTMC 231 250 yd3 5+ 12 3-6Z 90 m3! Unit Weight ASTM C 138 500 yd3 80 m3! Compre s sive ASTM C 31 6 cyla Strength ASTM C 39 1000yd3 3500 psi 3500 psi 65 m3'! 4 Mpa! 4 Mpa! + No requirement - report measured value. 1.5.3, Results of testing except for compres- 1,6,5, A supply of extra end plates and gaskets sive strength testing! shall be provided to the shall be maintained to allow resealing of tre- Contracting Officer at the end of each shift mies, if necessary, during which testing is conducted. Results of compressive strength testing shall be reported 1.6.6. A crane or other lifting device shall be within 24 hours of testing. available to completely remove the tremie from the water for the purpose of resealing or 1.5.4. Testing shall be accomplished using horixontal relocation. sanrples of concrete taken at the point of discharge from the mixer! the tremie hopper! 1.7. Placemaat Procedure or both!, NOTE: Location of sampling should be based upon elapsed time between mixing and 1.7.1. The contractor shall develop a compre- arrival at tremie hopper,! NOTE: The provisions hensive placement procedure plan in accordance of this section must agree with those of section with the provisions of this specification. This 1.4.5.!. plan shall be submitted to the Contracting Officer for approval at least days prior 1.5.5. Compressive strength tests shown in to beginning placements. Table 1.1 shall be conducted using three 6- by 12-in, 5- by 30 cm! cylinders at 7 and 28 1.7.2. All areas in which there is to be bond days. between steel, wood, or hardened concrete snd fresh concrete placed under water, shall be 1.5.6. Concrete temperature shall be measured thoroughly cleaned isxsediately prior to begia- rrnd recorded whenever other test irrg is conducted. ning placements. Cleaning shall. be accomplished using high pressure air or water jetting. Air- 1.6. Placement E ui nt lifts or pumps shall be used to remove mud, silt, or sand from placement areas. 1.6.1. The tremie pipe shall be of heavy guage minimum 0.25 in. .4 mm! wall thickness! 1,7.3. Placement of underwater mass concrete steel pipe with a minimum inside diameter of shall be as continuous an operation as possible. 10 in. 5 cm!. The tremie shall be marked to Placement shall continue uninterrupted until allow determination of depth to the mouth of the entire placement is completed. Interrup- the tremie. tions of placement through a single tremie sha11, not exceed 30 minutes without removal of the 1.6.2, Joints between sections of tremie pipe tremie and carrying out the restarting pro- shall be gasketed and bolted so as to be water- cedure. tight under project placement conditions. 1.7.4. The concrere placement rate shall be 1.6. 3. A hopperor funnel of at least 0.5 yd3 sufficient to produce a minirmrm vertical rise .4 m3! capacity shall be prrvided or top of of concrete of 0.5 ft/hr .2 m/hr!, calculated the tremie pipe to facilitate transfer of by dividing, the entire placement area ft concrete to the tremie. m2!! by the concrete production rate fts/hr! m3/hr!!. 1.6.4. A power hoist which is capable of steady vertical control! shall be provided to 1.7.5, Tremie pipes shall be spaced to give a accommodate vertical movements of the tremie. maximum concrete flow distance of 50 ft 5 m!. A stable platform shall be provided to support the tremie pipe, hopper, and hoist. 136 1.7.6. The placement shall begin with the tremie 1.8.3. After the cofferdam is dewatered, a pipe sealed with a watertight plate, The empty survey shall be made to establish final surface tremie pipe shall be sufficiently heavy to be elevations of the concrete placed under water. negatively bouyant when empty. "Rabbits" Klevations shall be determined at each location or "go-devils shall not be used to start the for which soundings were required. tremie. The tremie shall be sealed, lowered to the bottom, and fi11ed with concrete. The 1.8,4. Cores shall be drilled and recovered' as tremie shall then be lifted 6 in. 5 cm! to directed by the Contracting Officer For bid- initiate concrete flow. Concretesupply shall ding purposes, a minimum of cores shall be continuous until soundings indicate the re- be drilled at locations of maximumhorixontal quired embedment is developed. concrete flow. Additional cores may be required at no expense to the owner at all locations in I ~ 7,7. The mouth of the tremie shall remain which tremie seal is lost. embedded in the fresh concrete at all times unless the tremie is being completely removed 1.8.5. After removal of sheet piles! external from the water. At no time shall concrete be forms!, the surface of the concrete placed allowe'd to fa11 through water. Embedment shall under water shall be inspected by diver for be from 3 to 5 ft I to I 5 m! at all times. evidenceof cracking,voids, honeycomb,or other unsatisfactory concrete. A written 1.7.8 A tremie shall not be movedhorixontaliy report of this inspection shall be furnished while concrete is flowing through it. To re- within daysof completionof the inspec- locate a tremie, it shall be lifted from the tion. Suitable repairs shal1 be made, by grout water, resealed, relocated, and restarted in injection or underwaterepoxy injection, as accordance with section 1.7,6. indicated and approved. 1.7.9. AII vertical movements of the tremie 7,5. Recommendationsfor further work, Follow- shall be carefully controlled to prevent loss of ing are several areas in which the authors be- seal. If loss of seal occurs, placement lieve additionaI study wouid be beneficial.' through that tremie shall be halted immediately. The tremie shall be removed, resealed, replaced I, Confined placements. Determine if the and restarted in accordance with section 1.7.6. problems seen in the primary elements of Wolf Creek have occurred in other placementsand if 1.7.10, Tremies shall be relocated during the similar problemsseen in filling piles and small placement in accordancewith the placementplan diameter shafts with tremie concrete are related. and as ind ic a ted by soundings. Determine if there is a critical diameter or cross-sectional area below which successful 1.7.11. If circumstances force a suspension in pIacements are impracticable. placement greater than the time of initial set as determined by testing during mixture 2. Hydrostatic balance. The anomaliesin hydro- development!, then the surface of the concrete static balance noted in the Wolf Creek place- shall be green-cut after the concrete has set. mentsneed to be evaluated further in a program Placement shall not be resumed until the con- which includes measurementsand coring. Do the crete surface has been prepared in accordance anomalies represent areas of poor quality con- with section 1,7.2. crete? If so, measurementsof concrete levels made during a placement could serve as an '.7.12. Airlifts or pumps shall be provided to additional inspection too1, remove laitance which accumulates during place- ment. Airlifts and pumps shall be relocated 3. Temperaturemonitoring system. An inexpensive as indicated by soundings. system to monitor temperatures in a tremie place- ment and to compare measured and predicted 1,8 Ins ection temperatures needs to be developed. Such a systemcould alert field personnel to unexpected 1.$.1 The contractor shall develop an inspec- occurrences during a placement and present a tion plan covering locations and methods of starting point for post-placement verification taking soundings during the placement and coring. post-placement inspection. Soundings shall be taken each hour during placement. Soundings 4. Concrete density. Examine cores from several shall be spaced so as to cover the area, plus placementsto determinethe loss of density corners and at the tremie pipe discharge. This which may be expected for tremie-placed concrete plan shall be submitted approval by the as a function of flow distance from tremie pipe Contracting Officer days prior to begin- and depth of water in which placed. ning placements, 5. Temperature predictions. The finite element .8.2. Data from soundings shall be furnished approach to temperature prediction in tremie- to the Contracting Officer at the end of each placed mass concrete should be extended to shift during which concrete is placed. Data determine the sensitivity of the predictions from post-placement inspections shall be fur- to the many variables involved. nished oo later than days after the inspections are completed, 137 6. Confined placements. Examine the feasibility of using s vibrator attached near the mouth of the tremie pipe for deep, confined placements and perhaps for all mass placements. Such s technique appears of interest-but has not yet been tested nor proven and hence should not be used on prototype placements until testing has been carried out. 7. Temperature cracking. Examine the crack re- sistance of concrete which hss set and cured under the thermal gradients known to exist near the extremes of a massive tremi,e placement. 8, Concrete flowabiliry. The flowability of a co~crete appeared to determine the flow pattern which was exhibited once the concrete left the tremie. There needs to be a test which can measure that flowability directly, Perhaps a variation of the vane shear test used in soils testing could be developed. 9. Thixotropic admixtures. Examine uses for thixotropic admixtures for concretes to be placed under water, A thixotropic concrete would be beneficial in applications in which only limited flow is desired after the concrete leaves the mouth of the tremie or is exposed to running water. 10. Nixture optirsixation, Develop more economical concrete mixtures for mass tremie placements. The work done in this project has defined the characteristics for successful placement. Can more economical mixtures be developed to match those chsracteristicsf 13S REFERENCES 16. Anderson, Arthur R. "A Study of Sub-Aqueous Concrete," Journal of the American Concrete 1. American Concrete Institute Committee 304. I t t t P * d g 9 1. 33, J y 9 b y "Recommended Practice for Measuring, Mixing, 1937, pp 339-346. Transporting, and Placing Concrete," Journal of che American Concrete Institute Proceedings 17. Halloran, P. J. and Talbot, K, H. "The Vol. 69, No. 7, July 1972 pp 374-414. Properties and Behavior Underwater of Plastic Concrete," Journal of the American Concrete 2. "Concrete Down the Spout," Concrete Construc- I tlt t Ptptt ~ 1 8 V l. 39, I * 1943. pp. ~tion Vol. 13, No. 7, July 1968, pp 247-250. 461-492, 3. Netherlands Cosssittee for Concrete Research CUR!, Cosmittee C17. "Underwater Concrete," 18. Williams, J. W., Jr, "Tremie Concrete Con- Heron, Val. 19, No. 3, 1973. trolled with Admixturesp" Journal of the American Concrete Institute Proceedings Vol. 4. Gerwick, Ben C., Jr. "Placement of Tremie 55, February 1959, pp 839-850, Concrete," S m osium on Concrete Canstzuction in ueous Environments American Concrete 19. Ozegon Department of Transportation. The Institute Special Publication No. 8, 1964. Columbia River -205! Br id e Undated br achur e . 5, Gerwick, Ben C., Jr. "Under~ster Concrete Construction," Mechanical En ineerin Vol. 94, 20, "Record Segmented Bridge Making Headway," No. 11, November 1972, pp 29-34. En ineezin News Record Vol. 199, Na. 20, November 17, 1977, p, 16. 6. Powers, T. C. "Studies of Workability of Concrete," Journal of the American Concrete 21. "Long Box Girders Will Span Columbia River," I ttt t 9* dt g V l. 28, 1932, pp 419- En ineezin News Record Vol. 187, No. 15, 448. October 7, 1979, p. 15. 7. Hezschel, W. H., and Pisapia, E, A, "Factors 22. "Tight Bids Fall Low on Bax Girder Bridge," of Workability of Portland Cement Concrete," En ineerin News Record Vol, 202, No. 25, Journal of the American Concrete Institute January 18, 1979, p. 38. Proceedings Vol, 32, 1936, pp 641-658. 23. "Special Forms, Equipment Cast River Piers," 8. Tattersall, G. H. The Workabilit of Concrete En ineerin News Record Vol. 200, Na. 25, The Cement and Concrete Association, London, June 22, 1978, pp 58-59, England, 1976. 24. Carlson, Ray W. "A Simple Method for the 9 ~ American Society for Testing and Materials. Computation of Temperatures in Concrete Annual Book of ASTH Standards Part 14, Concrete Structures," Journal of the American Concrete and Hineral A re ates ASTH, Philadelphia, 1*t tt 9 d' g Vl. 34,77 ob Penn., Latest Edition. 9 b 1937, pp 89-192. 10. U. S. Army Engineer Waterways Experiment 25. Couch, Frank B., Jr., and Ressi de Cervia, Station WES!. Handbook for Concrete and Cement Azturo L. "Seepage Cutoff Wall Installed Vicksburg, Mississippi, 1949. Through Dsm is Construccion First," Civil ~gpl. 49, II. !,J *y 1979, pp ll. American Concrete Inscicute Cosssictee 211. 62%6. RecommendedPractice foz Select in Pro ertions for Ha-slugs Concrete ACI 211. 3-75, American 26. "Concrete Cutoff Extends 278 ft to Seal Concrete Inscitute, Detroit, Hichigan, 1975. Old Dam's Foundation," En ineerin News Record Vol. 197, No, 4, July 22, 1976, pp 14-15. 12. Hacher, Bryanc. "Partially Compacted Weight of Concrete as a Measure of Workability," 27. Dunn, Albert. "Diaphragm Wall for Wolf Journal of the American Concrete Institute Creek Dam," USCOLDNewsletter Issue No. 53, Proceedings Val, 63, 1966, pp 441%49. July 1977, pp 3-7. 13. Hughes, B. P. "Development of an Apparatus 28. Fetter, Claude A. "Wolf Creek Dam Dia- to Determine the Resistance to Segregation of phragm Wall Completed," USCOLDNewsletter Fresh Concrete," Civil En ineerin and Public Issue No, 60. November 1979, pp 16-19. 17 k 8* '* V l. 56, 9 . 658, 8 y 1961, pp 633-634. 29. Fetser, Claude A. "Wolf Creek Dam Remedial Work, Engineering Concepts, Actions, and 14. Ritchie, Alistair, G. B. "Stability of Results," Transactions of the Thirteenth Inter- FreSh COnCZeCeMiXeS," Jpurnal Of the Canatruction national Con ress on Lat e Dams ICOLD, New Division ASCE Vol. 92, No. C01, January 1966, Delhi, India, 1979, Vol. 2, pp 57-81. pp. 17-36, 30. Holland, Terence C., and Turner, Joseph 15. Scrunge, Christian. "Submarine Placing of R. Construction af Tremie Concrete Cutoff 6 * t by th I'* I ~ -8 th 4," ~72 t I Wall Wolf Creek Dam Kentuck Miscellaneous the 1970 Of f shore Technola Conference Vol. Paper SL-S0-10, U. S. Army Engineer Waterways 2, Paper 1311, pp 813-818. Experiment Station, Vfcksburg, Mississippi, 139 September 1980. 31. "Slurry Wall Construction," Concrete Con- t t'ee V !. 78, 8 . 3, M 7 6 1973, pp 98- 93. 32. Nash, Kevin L.,"Diaphragm Wam1 Construction Techniques," Journal of the Construction Division ASCE, Vol, 100, No. C04, December 1974, pp 605%20. 33. Polivka, Ronald N. and Wilson, Edward L. Finite-Element Anal sis of Non-linear Beat Transfer Problems Department of Civil Engineer- ing, University of California, Berkeley. Report No. UC SESN 76-2, June 1976. 34. Carlson, Roy W., Houghton, Donald L68 and Polivka, Nilos. "Causes and Control of Cracking, in Unreinforced Nasa Concrete," Journal of the 8 'ce C *ce 1 t'c t 1 8' 8 Vcl. 76, 8 . 7, 3 ly 1979, pp 811-837, 35. Corps of Engineers, Civil Works Construction Guide S ecification Concrete CW 03305, December 1978. 36. Corps of Engineers. Standard Practice for Concrete, EN 1110-2-200, November 1971. 140 APPENDIX A: CONCRETE MIXTURE PROPORTIONS MIXTURE EVALUATION TESTS 1. Mixture proportions for each of the 11 mixtures evaluated in the small- scale laboratory tests described in Chapter 1 are presented in Tables A-1 through A-11. 2. Data presented in this appendix are summarized in Table 2 of Chapter 1. 3. Only data for Mixture 1 Table A-1! are presented in this volume. Data from remaining mixtures may be obtained from the authors. 4. The following conversion factors are required for the tables in this appendix: 1 lb mass! - 0.4536 kg 1 lb mass!/ft 3 3 16.02 kg/m 1 fl oz/lb 65.2 ml/kg 3 3 1 yd 0.7646 m 141 APPENDIXB: CONCRETEMATERIALS MIXTURE EVALUATIONTESTS 1. The componentsof the concretes evaluated during the small-scale tests de- scribed in Chapter 1 are described in the following paragraphs. As far as was possible, the samematerials i.e., samesources! wereused for the large-scale placements described in Chapter 2. and Gravel and were from that company's Pleasanton, California, quarry operation. Coarse aggregate: 3/4-in. !9-mm! nominal maximumsize Absorption: 1.0 percent Specific gravity: 2.68 Fine aggregate: Top sand Absorption: 2. 0 percent Specific gravity: 2.68 3. Cement. Cementwas purchased from the Kaiser CementCompany plant at Permanente,California. The cementwas a Type II conforming to ASTMC 0. 4. Pozzolan. The pozzolan used was a natural material sold by Airox Earth Resources,Santa Maria, California. Thematerial met the requirementsof ASTMC 618, Class N. The specific gravity was 2. 54. 5. Bentonite. The bentonite used was sold by the American Colloid Companyand was markedwith the trade name"Volclay 200." The specific gravity was 2,71. 6. Admixtures. Admixtures used were from laboratory stocks with the excep- tion of the thixotropic additive!. Water reducer/retarder: Sika Plastiment. Air-entraining agent: Master Builders AE- . Thixotropic additive: Sikathix manufacturedby Sika ChemicalCorporation. 7. Water. City water, Berkeley, California. 143 APPENDIX C: SUMMARIZED DATA MIXTURE EVALUATION TESTS 1. Data for each of the three tests performed on the ll concrete mixtures are presented in Tables C-1 through C-10. These data are summarized in Table 3, Chapter 1 ~ 2. Each test for which data are presented in this appendix represents three batches of concrete, as is explained in Chapter 1. Detailed data on a batch- by-batch basis are presented in Appendix D. 3. Only data for Mixture 1 Table C-1! are presented in this volume. Data from remaining tests may be obtained from the authors. 4. The fol1owing conversion factors are required for the tables in this appendix: 1 in. 2.54 cm 1 lb mass!/ft 3= = 16.02 kg/m 3 1 lb force! - 4.448 N 2 1 lb force!/in. 0.006895 MPa To convert deg F to deg C, deg C = deg F 32!/1.8 144 APPENDIX D: DETAILED DATA MIXTURE EVALUATION TESTS l. Detailed data for the tests performed on each batch of concrete of the ll mixtures tested are presented in Tables D-1 through D-29. These data are sum- marized in Appendix C and in Table 3, Chapter 1. 2. Only data for Nixture 1, Test 1 Table D-l!, are presented in this volume. Data from remaining tests may be obtained from the authors. 3. The following conversion factors are required for the tables in this appendix: 1 in. = 2.54 cm 3 3 1 lb mass!/ft = 16.02 kg/m 1 lb force! 4.448 N 1 lb force! /in. 2= = 0. 006895 HPa To convert deg F to deg C, deg C = deg F 32!/1.8 146 TA BLE D- I . CONTRE TE 'TES'T ' DAT' A. M iXWURE i TEST ' J- QFVa'RA< w HARA<=P+gis~cs 'p. 'TAKIN,92K %~M ~%W, IA/~ 4k i JO 0 +vs 11. o i3, Ti W% o F as'T t hJ'I WI 4 4 3 ~ P!IVAN 4. % L6.6'b |ACED If O 4- V ~ & ! 5, CoH&~c h!! iebFL e. 07 0 d7 C,O 4 AvK Sm~aa c+moN ~.SI +~ 0.77 ~~~ 0 79 l47 I T A BL E D I . C ON T I NU E D! t ; v. ma w sea a~v a 6 9Kv5Lc zm8'Nw ig, C.OhhVQKSS'l v 6 '5&455 5W4 gee-~ ~ih!$ ~g~SI 4-g ]O. 54 MAcP' C OSS its APPENDIX E: SOUNDING DATA LABORATORY PLACEMENT TESTS 1. As is described in Chapter 2, the tremie concrete placed in the large-scale laboratory placements was broken into three approximately equal segments. Soundings were taken at 20 locations over the surface of the placement box at the conclusion of placing each of the three segments of concrete. The sounding pattern used was shown in Figure 17, Chapter 2. 2. Soundings were taken using a weighted plate attached to a measuring tape. The plate was of sufficient area to prevent its sinking into the soft concrete. 3. The data was obtained as distance from a fixed reference point to the sur- face of the concrete under water. This data has been converted to thickness of concrete in place by subtracting test readings from those obtained at each point prior to each test. These reduced data for each test are presented in Tables E-1 through E-5. 4. Only data from Test 1 Table E-1! are included in this volume. Data from remaining tests may be obtained from the authors. 149 T'ABLE E- I . C INCR EVE T'H 1C K,- .NE,S'5 AS DKTKRM t4c.p BY SOUNDING5, ~iE'5T' 1. APPENDIXF: SURFACEPROFILE DATA LABORATORYPLACENENT TESTS As is described in Chapter 2, the surface of each of the tremie concrete placementsin the laboratorywas mapped to establish surfaceprofiles. Measure- mentswere taken at five locations laterally outside edges, 1 ft 0.5 cm! in from the outside edges,and centerline! and at every 1-ft 0.5 cm! interval along the long axis of the box. 2. Measurementswere madedown from a fixed plane to the surface of the con- crete. Thedata presentedin TablesF-1 throughF-5 havebeen reduced to give act~1 concrete thickness. 3. Figure14, Chapter2, showsthe left/right orientationof the placementbox. The tremie was located at station 1.5 with flow toward station 20. 4. Onlydata from Test 1 TableF-1! are.included in this volume.Data from remaining tests may be obtained from the authors. 151 FlNAL CONCRETE TH i CKNE.S'S, lNC HES, TES'T i . J-iN.= 2..54c~! APPENDIXG: COLORLAYER- DATA LABORATORYPLACEMENT TESTS 1. As is describedin Chapter2, cores were drilled in the hardenedconcrete to determinethe final distribution of the variously coloredsegments of con- crete. Thecoring pattern usedwas presented in Figure 14, Chapter2. 2. Coreswere recovered, measured, and logged. In caseswhere complete core recoverywas not possible usually due to mechanicalrather than concrete prob- lems!,the total thicknessof theconcrete at thelocation of thecore was used to determinethe color distribution. For severalcores it will be notedthat the lengthof corerecovered is not equalto the thicknessof the concreteas reportedin AppendixF, Thediscrepancies are dueto ridges on the concrete surfaceand minor errors in measuringthe lengthsof the cores. In thesein- stances,the total thicknessof the coloredlayers has been made equal to the thickness determined during the surface profile measurements. 3. Datafor the centerline andright edgeof the box for the five tests are presented in Tables G-1 through G-10. 4. Onlydata from the centerline, Test 1 TableG-l!, areincluded in this volume. Data from remainingtests maybe obtained from the authors. 153 APPENDIX H: TEMPERATUREINSTRUMENTATION PLAN PIER 12, I-205 BRIDGE 1. The instruments used to record temperature development in the tremie con- crete seal of Pier 12 of the I-205 Bridge were Resistance Thermometers supplied by the Carlson Instrument Company,Campbell, California. A total of 34 instru- ments and 4523 ft 379 m! of lead cable were used. 2. All instruments, cables, and switches were tested under hot and cold condi- tions in the laboratory prior to being used in the field. All elements performed satisfactorily during testing and during actual field use. 3. As noted in Chapter 3, one quadrant of the pier was instrumented, Instru- ments were placed in four planes perpendicular to the long axis of the coffer- dam.. These planes were designated Row 1 through Row 4. Each row was made up of two or more vertical lines of instruments. Figure H-l shows the general in- strumentation plan in relation to the cofferdam. Figure H-2 shows a blow-up of the instrumented quadrant while Figures H-3 through H-6 show the horizontal locations of the instrument lines within each of the four rows. Figures H-7 through H-17 showthe detailed vertical locations of the instruments on each line. * 4. Vertical instrument lines were made up of a steel supporting cable with the instruments attached to the cable at the appropriate elevations. The steel cables were heavily weighted at the lower end and were attached to the cofferdam bracing at the upper end. 5. All lead-in cables from the instruments were connected to a central terminal/ switching board. This board was in turn connected to a variable resistance bridge Carlson Box! which was balanced to obtain the readings. A schematic of the system is shown in Figure H-18. 6. A listing of instrument numbersand recording channels is shownin Table H-l. The particular sequenceshown was selected to allow channels 1 through 6 to be connected to the instruments which initially would be in contact with the concrete. * Of the figures showinglocations on eachvertical line, only FigureH-7 is included in this volume. Remaining figures may be obtained from the authors. 155 SECT I ON T HRO F IGURE H-6 . SCHEMAT'I C OF IklST'R.'J- MENT ROW 4 . SEE PIGS. H-I& ~~a I-I-l7 FOR EX AC.T VERT ICAL LOC AT' ION 5, NOT T'0 SC>I a. IFT=O.SO C Q A H g E'L5 CHANNELS C HeMNELS ZS- S4 1- LZ. l3 -24 i-N= I Xeo l- t= lseX R'E sly'TOADS ~ REMI STAN~K P'ISUP,E. H-IQ., SCHE NAITIC DiA6RA OF lbJSTRUhAENTAT I N TE R M I NA L B OA R D. 163 APPENDIXI: DATA RECORDINGAND REDUCTION TEMPERATURESIN PIER 12 SEAL CONCRETE 1. Temperatureswere read nominally every 2 hours' Actual reading times varied slightly due to conflicting activities within the cofferdam and the schedules of the persons taking the readings. Actual start and stop times for the read- ings were recorded on the data sheets. These two times were averaged to estab- lish the reading time for each set of data. 2. Total time required to complete one set of readings was approximately 20 minutes. Six of the data channels were read at the beginning and end of each sequence. The values for these two readings were then averaged to offset any discrepancies which might have ocurred due to the time required to complete the entire sequence of readings. 3. Readings were taken in ohms by balancing a variable resistance bridge Carlson Box!. This raw data was converted into temperatures following instruc- tions provided by the manufacturer of the resistance thermometers. 4. The temperatures obtained at the actual reading times were further reduced to provide temperatures at the nominal reading times every 2 hours through 80 hours and every 10 hours from 80 to 380 hours! using a straight line inter- polation technique. This last step was done to allow easier comparison with predicted temperatures. 5. Reduced temperature data for the 33 instruments are presented in Tables I-1 through I-33. 6. Only data from Instrument 8 Table I-8! are included in this volume. Data from remaining instruments may be obtained from the authors. 165 APPENDIX J: PREDICTED VERSUS MEASUREDTEMPERATURES PIER 12, I-205 BRIDGE 1. The tables in this appendix compare the temperatures predicted using the Garison Method with those actually measured in the seal concrete of Pier 12 of the I-205 Bridge as is described in Chapter 3. 2. Due to the limitations of the Carlson Method which are described in the text, predictions made using that technique are valid only for instruments for which one-dimensional heat flow can be assumed. Therefore, the following tables in- clude only those instruments in the interior of the pier for which this assump- tion is valid. 3. The following tables are included: a. Table 3-1, Top of seal instruments. b. Table 3-2, Mid-depth instruments. c. Table J-3, Bottom of seal instruments. 4. Note that in Table 3-1 a range of predicted values is given. This was done since a variable thickness of concrete was actually placed over the top instru- ments. The cover was calculated to be: Instrument No. 4 2.0 ft .6 m! Instrument No. 15 0.7 ft .2 Hi!. Instrument No. 21 2.6 ft .8 m! Instrument No. 22 4.6 ft .4 m! 5. Note that the readings for instruments No. 5, 7, and 9 are significantly below the predicted values. See Section 3.3.4 of the text. I l67 F J z . PIED' c TK 9 vs. MEAG URF 0 T'ENl'PFR, &TURF-~, M t D DE P TH . lM sTR UMEN t 5 NE A R. t" KNw~RL-l4 F- TR.RV iE +E44-. P'W gB>v E wAsa ~F. st&~ 169 TASK-E,J - 3. PRRDlGTBD VS,MEASURED TKNtPE,R,&TURKS, 507-7 o< oF SEAL iQWEF.ioR, { w~swzu wawwc. APPENDIX K: LISTING OF PROGRAM TEMP Note: Flow chart follows listing.! PROGRAM TEMP 1 NP UT a OUTPUT a PUNCHl COlarNIQN /DES / 8 ~ Ha 0 f HED 18 ! ~WED 2 5! COMMON /E I DAEVA/ V ~ PR, NFC q NF8 ~ T C 400 ! COMMON /GRlOCU/ X 0!, Y 0! D I MENS 1 CIN PX 0a 30! a PY 30 ~ 30! g NE 30! D 1 |alEN 5 l C.Iv NOD 5 ! 1 R EAO 900 y MODF a WEDa HE D2 I F iirlGDE ~ EQ ~ 5HSTUP ! GO To QQOQ CALL T [ TLE HEAD 1000 q da WaD y INr Nda NH ~ ISa lP I F I P ~ EU ~ I ! PUNC H 900' MCDEg HED PRlNT 20&Of 8 f Hf D V =8+ H' D/2 7 ~ 8 = H/2 ~ 0 = 0/2 ~ IF IK ~ t4 ~ 0! Gati TG a0 IPEAD 1050a X l ! a I If NH! REAIJ I050a Y I ! a 1=!a NH! GO ErJ 60 50 CALL CEN aRD N8aNH! 60 NH1 = NH 1 NO 1 = NI:I 1 Np = NH~NH NFE = NFa14r4H1 I'=-Y 1! DO 110 L = I a NH DO 110 J = 1a N8 PX a J! = X J! P V L, J! = Y L! 110 CQNT[NUE Chl L C CNCQP NB 1 a NHl ! C ALi. HEAT~II P ! C ALL 1 TLE rae I N E 2 0 r.'i0 a N d a 3, NI r aH a e a 4 P a NF T Iak INE 20'00 I F I P ~ FO ~ 0 ! raQ T Q 139 L=2 A =8 HN C D L,~r. I l' =at-N T DA TA lF Ia' ~ trJ ~ 1 ! raUNCH 9000y AyQ ~ Anil ~ A ~ 8q A aB r-'UNCW 5 300 ~ N9 a L 1.~ " J = 92a .'4H D l 13 i 1=1 a I4I4 K =K+1 HJRCH >lu3 ~ Kg~A. Ja I! SPY J ~ 1! 136 CCNE l xu;"- K = 0 L= 1 J=2 A = r P iJIJ C 5i;i~0 a ~Vol. 53doa il Dri a0 L la N I '4- I 1 I= v L I ~ LT ~ 0 ~ ! 9=2 J.J I 4d J 1 a N3 ~ J! 7 + J I ~%I< ! 172 IF J ~ EC ~ 9t4! GQ TG 140 N J! = tl-T + J - L+NR I ! IF La EO ~ NH 1 GG TG 140 K = K + NaO ! = K kOD ! = NO + K+L NOD 3} = NOD 2! -t. NGD ! = NQO 3! NB NOD ! = trOO 4! + 1 IF Ir ~ EV ~ 1! P'JNCH eOoor NtjD I ! f I 1 r5 l ~ Nt~ TC K! 140 CONT IKUF. K 1= NH + I L PRINT 2100 r P Y Kl ~ 1!r X Jl r J = 1 ~ NUl PRINT 2101 ! F L eEQ e NH! GD TG 150 NZ ' = NDI riL tv = NET + 1! N2 N 1 = N + Ndl 1 P HI NY 24'3 0r NE J! ~ J = I r NBI ! PR INT 2400 ~ TC J!r J = N ~ NI! 150 CCNT INUE PRINT 2200 ~ PX I ~ J! r J = I ~ %8l PRINT 4000 PRI NT 6430 8=0 L=' DD 200 t =1 r NH IF PV Lr 1! ~ GT ~ 0 ~ ! GG TU 210 ht=M+1 Zt CON 7 I tQ UE 210 N= NU 1 +NHI-hi IP ~ 6'0 ~ 0! Ga TV 220 A=9HCUNVECTI ti=RHCN DATA UieCH v040rAr Br' t3rArRrA ~ 8 PUNCH 5000r L 220 L=1 f 4M+NI3 J= I+Nt' IF I P.EQ ~ I ! P'JNCtr 6500 ~ t r I ~ J r NB Pk INT eao00r L r Ir JrNi! =NHI ht I = lP-NU J =NP IF I P ~ t..O ~ 1 ! PUNCH 6500 r L ~ I r J r NU Pa INT trhi rL r Ir J ~ NB V= I L=L+ I I =Nt3~ NH 1+? J= I-I IF I P ~ Fu ~ 1 ! P JNCH 6500 rLr I ~ J r K PP I NT o.i00r L r I ~ JrK L =t.. 0 t< I.' 1 1 =NP J= I I IF I+ ~ Cid I j PUNCH ei500 r L r I ~ J,K Pl-' I N T <>rit! 0 r L r Ir JrK GC Tti l wlg3 FLeMA T Air 3X r 1 dA4 ~ /1 5A4 '! t 900 FFtP4fAT >F10 ~ 0r 515! Ddt! F Ot l73 20 ~ ! F ORMAT ///2K, 0 0 I MENSION 5 QF STRUC TVRE ¹ ~ 2OX~ 1/ 4'4Xq ¹ ~ w y 2/ LENGTH X! => /F5 ~ I f¹ FEET¹ y 20Xy + g% ~ 3/ HE 1GHT Y 1 =¹yF5 ~ 1 y ¹ FEET¹ 20Xq ¹ ~ ¹ p 4/ w I!!THT Z } ~¹yFS ~ 1~ + FEET¹ ~ 204r ¹ ~ ~ ~ ~ X¹ 5/ 4HX« '+e¹y 20'«t06/ FORM AT //1X,¹45Xy HL WZIGt T r4 I NODALPGI NTS FOR TEMPERATUREANALVS IS ELEM 1FNT N JNtHERS4N3 ELEMENT CREATION TI MES HOURS!¹ I 21 00 FQAYAT / «F7 ~ 1 y 3H ¹ y 20F6 ~ Oq/! '101 FOHMA T » ¹ ! 2200 FORMAT BX ~ 121 H+ i y /IOXg 20F6 ~ 1 l 2300 F ORhitAT 1 3K i 20I6 I 40002400 FORMATFORMAT /+ 13X ~ C23!FAE NT 6 RL ~ 1 I! NE ¹ ~25X ¹ HQR I ZQNTAL 0 ISTANCE FROM CEN TERL INE l OF STRUCTUHE> FEET¹1 500t! F !RMAT { 8 I 5 ! 5 1 00 F QRMA T I 5 y SK y 2F 1 0 ~ 4 ! 60 00 f QRMAT a 15 g 20 X ~ I'5e 10X yF 10 ~ 4 I O400 t-ORMAZD //// 3 X ¹ CQNVFCTI Ghl ELEMENTS AND NQOAL PQ IN T OATA ¹ / I 8X, i< El t WENT4 ~ IOX ¹ NODALPQINTS + ~1 OX+STEP FUNCT I 0 4¹ / 8 X q ~ NUMBER '-> ~ 10 X~ * I ¹1 6500 F QRMAT I 5 I SX IS! c>o00 FORMAT QX y I 5 y 11Xy ISED16 y 15Xy I 51 9000 F CREAT X «RAN! S TOP I=ND SUe QUT INE T I TLE CQM»tbN /DE / Jq Hy O HEQ 18 ! q HFD2 15 I -ik I'NT 23 0' HE'3t HE32 2000 FORMAT HI ~ 2X r 19A4«15A41 k E TUHN E t«it! Ut!f'OUT INg CONCOP NUI f NHI C 4 4:!N /!LS / 8 y HpD «HEQ 18 ! ~HED2 15 I COWL!N /T {Mr=VA/ V p»7gNFC ~ NFR ~ TC 490 'I 4EAI! 1!Ol! PR kT NFC NFi3 IF ~ T ~ 3 ~ 0 ~ ! RT= V/PR IF t~+ ~ EO ~ '! ~ ! P»= V/PT 8R=H/t' 'f N= 1 I < NFC ~ T ~ 01 Il= f N SVORO V I INL GEIVGav wig rnlW! CCI Hl k Q.'0 /O E 5 / f! t W ~ O r HF O 1 I! ! Ci3NlikON /G HI DCQ/ X 0 } r Y 0! OI-'HEr $ ION G ! r G 1 ! r G2 ! rG3 ! OA1 A G I ! 1=1 r5 ! /20 ~ r !Os r5 ~ f 2t r I ~ / OaTa GI I I r 5! /75 ~ r 31 ~ f IO ~ r 5t f 0 ~ / DATA G2 l!r I=it /43 ~ r 18 ~ r6 ~ r2 ~ rO ~ / DATA G3 I ! r I=1 r 5! /I|! ~ r5 ~ t4 ~ t2 ~ tle/ H2 = W/2 ~ NH2 = H2 CALL GR Ill HP r Xr G3rG2! NW = NAP +I Y !=-20 ' Y ! =- IO ~ V ! =0 ~ V NH! =H K1 = N 1 OQ 100 L = lr Kl Y L + 3 ! =ilI I 2- X 8- l ! I F Y L+3! ~ EO ~ '! ~ l Y L+3!= ~ 5 K =NH-L Y K !=W- Y Lt 3! 100 CONT I rtU~ CALL GR IO '3 r NB Xr Gr Gl! RETURN E,NO .'~Ji 3 - IJ 'JT IA IQ t< r 4r Ztbr Gl l U ikI 43l 3H Z i0!r !r Gl ! Z ! = 0 OQ a'0 J lrS C = II Z l IF C ~ LT ~ G1 J ! ! tU TQ 20 DQ 10 I 10 I's N + 1 Z d! = i 4-I ! t G J! IF Z 4! GT 's-GI Jl ! ! GQ TQ 20 I J CQ 9 I I I DQ 250 J=-1!K PF3 0 1 I! =0 ~ I 3=.NW 1-0 I 4=1 DO 320 I=ltI3 VQ 3!O L=l>F11 IF Y<1! ~ ~T. L ! GQ TQ 310 F 3= 1 L+ 1! T2 f +1! !/l3 r 4= T1 L! -12 L! !/o ~ 0 0 J =- 1 > r ~s 1 K=Kt 1 Fl= Tl L!-X 4! >F4 F 2= T 1 L i 1 !- X J ! '+f. 3 1C f;!=F 1+ Fc'. f' ll~< I ~ L Y I! !! 3{-0 C N'f IREE I 4=L GO TO 320 310 CCNT I r UF 320 C4NT I RUE 2 300 F 'Hr;AT / /2X + PR !DuCT ION PATE 4 / ! 2 0~0 F i ! fe 9 A T t. HE I G T ~ f EET T II4lt:. y WOJ RS CAYS ! T IHC s I -H Jf~S DAY S ! aRODUC. T ION HATE PER FOOT QF 8 I SE 'f ~ / l.' <0X i 1 .3i.f A t' Cf'O'TEHL I tvE i 13X i 13HAT X-t9OVNDARY v 15X ~ C Ui3 IC YhkD~ PER WGUR /1'.~X i >0 > t9X gf 7 ~ 2i 21X y Ff ~ 2! i l 00 F QwflAT 1 2Xt 4i2 < >i tF+ ~ 2 t2H < yF6 ~ 2 y2WI I y !SXyFB ~ 2! "400 F '1 fc I4",A T < / //. x > ~!iaLC IF tFD RATE 'jf RI SF AT CFNTERL I VP QF STAUCTURE4 ! i' 'i 1 0 > GHANA // /3 x e " 'iaLC IF I ED RATe GF R I SE AT x-BQUNDAHY OF 5TRUC TURF+ ! ' 'LT L GUBht!UTI NL r 177 SUAR04T INE HEATVI T ~ Away My IP! D 1'At NS IfIN T 13! pF 1 13! ~ AGE 13! DATA ACiE I ! p l=1 f 13! /0 ~ f 20 ~ 40 f 60 f 12 ~ 0 ~ 2 ~ 8 ~ f600 f 96 ~ f 180 ~ l" 290 ~ >1000 ~ / IF T 12! EQ ~ ~ 0001! T 12! =0 lF T 3! ~ EO 0001 ! T l3! ~0 ~ PA INT 2000 rF Z~.En.O! ra TQ Va HEAD 1 000 sF 1 PR lNT ? 200 GQ TO 100 90 PRINT 2100 100 DO ZOO l=1t 13 HI~ = A t B/? . ! 4T I ! M +ED ~ 0! GQ TO 150 I F F 1 ! ! +EQ ~ 0 ~ ! Fl I 1= 1 ~ HRM =HR4F 1 I ! PRINT 2300yAGF 1! yhfkyF1 I! yHRM GO TQ 190 0 PRINT ?300y*GE I ! fHR HRM~HV 1'o.0 200 CONl I'VE I F IP ~ F. J ~ 0 ! GQ TC 999 ! L=1 K=12 A =OHHEAT GEN R=8HFUNCT ~ PUNCH 9000yAgHpAy ByAy8 Ag8 PUNCH 3000tLtK PUNCH S100q ACiF l! y T l ! ! il 1 ~ 13! I 000 F DRMAT 1 3F'5 ~ 01 2000 FVRM A T I //3Xi ViREAT GENERATI Oh FUNCT l QN + ! 21 OO f f.lRI~AT 8 X y *T VE.y HOURS HEAT RAT Ey 9TU/FT 3/HOUR 2200 F UR4'Al 15 X T I NE HUVRS HEAT RATE ~ BTU/FT 3/HOUR AX O' FACTOR NIQDIF IEQ HEAT RATE 2300 O'QHMAT OX FS ~ 1 9X UFO 1 20X F6 2$6r>F8 1! 3000 FORMAT 3IS! 31 00 FGRMAT OF 10 ~ 2! OOOO F dHkAT X y OAO! 9999 RETURN I- h,D j.78 180 ~~o+ WlM PVAGQ gpss~ fÃ>A7F zrfM i'd% case ararat ~g$'M% Pe YB-CV. 181 APPENDIX I,: USER INSTRUCTIONS PROGRAM TEMP Program TEMP is described in general in Chapter 5. Below are specific instruc- tions concerning preparation of the cards required to run the program. I. Problem Initiation and Title - A5,3X,ISA4,15A4! Total Cards = 2 Column Variable 1 - 5 MODE Punch START, Problem Initiation 6 - 8 BLANK 9-80 HED Description for Identifying Output Second Card l- 60 HED2 Continuation of Description can be blank card! Note: Only information on first cax'd can be used directly with DETECT. II. Structure Dimensions, Grid Generation and Punch Control Card F10.0,5I5! Total Cards = 1 Column Variable 1- 10 Tots.l Base Length of Structure, feet X-dix'ection! 11 - 20 Height of Structure above foundation!, feet Y-direction! 21 - 30 Total Depth of Structure, feet Z-direction, normal to 2-D grid! 31 34 35 IN Option a! 0: Automatic Grid Generation. Option b! 1". Grid coordinates specified by programmer. 36- 39 40 Only specified if Option b! IN = 1; otherwise, leave blank for Option a!. Total number of grid lines specified along base length of structure fx'om centerline to X-boundary max. = 18 for DETECT program!. 41 44 45 Only specified if Option b! IN = 1; otherwise, leave blank for Option a!. Total number of grid lines specified along height of structure, including any in foundation max. = 18 for DETECT program!. 182 Column Variable 46 49 Option c! 0: Incremental Construction - All elements have specific creation times established in this program. Option d! 1: All elements exist at start of program - used for analysis of existing structure. 51- 54 55 IP Option e! 0: No data cards punchedfor input into DETECT program. Option f! 1: punch data cards. III. Grid GenerationCards 8P10.0! If Option a!, total cards= 0 no cards!. If Option b!, two sets of cards, as many as necessary to specify X and Y coordinates of grid. Column 1- 10 X ! .X coordinate of grid measuredfrom centerline of structure. X l! must equal 0. ll- 20 X ! Consecutive X-coordinate from centerline to X- boundary. etc. 71 - 80 X 8! Consecutive X-coordinate from centerline to X- boundary. Next Card if necessary! 1 10 X 9! etc, X NB! Last X-coordinate must equal total base length 2 total numberof X-coordinatelines equals NB specified on Card II!. Column Vari ah 1 e 10 Y l! If foundation coordinate, specify distance below structures as negative value example: 20 feet below structures = -20!. If no foundation elements, Y l! must equal 0.0. 183 17 - 20 Y ! Foundation or structure coordinate at foundation and structure intercept. The ordinate must equal 0.0. etc. Y NH! hast Y-coordinatemust equal height of structure abovefoundation!. Total numberof Y-coordinates lines equals NHspecified on Card II. IV. F10.0,215! Column Variable 1- 10 Option 1 a! - Production rate specified, average cubic yards per hour. Can be left blank if Option l b! selected. 11 20 RT Option l b! Total time to completion, from start to finish for structure concreting operation. Canbe left blank if Option 1 a! selected. 21- 25 NFC Option 1: 0 Constant rate of production, constant rate of rise over entire surface. Option 2: Specify total numberof specific data set points given to establish rate of rise at centerline of' structure max. number = SO!. 26 30 NFB Option 1 or 2: 0 Option 3: Specify total numberof specific data set points given to establish rate of rise at X-boundary of structure. Note: Option 1: Constantrate of rise over entire surface. Option2: Rateof rise specifiedat centerof structure or X-boundary!, constant over entire surface. Option3: Rateof rise specified at center andat X-boundaryof structure, linear variation between center and X-boundary constant rate between center and 2-boundary 184 total cards = 0 no cards!. V. Rates of Rise S ecified 4 F10.0! If Option !, If Option !, as many cards as required to specify NFC number of data points time, height! at centerline of structure. If Option !, as many cards as required to specify NFB number of data points time, height! at X-boundary. 'a d Column Variable 1-10 FT l! Time at height No. 1 must = 0. 11 20 FH ! Height No. 1 must = 0. 21 - 30 FT ! Time at height No. 2. 31- 40 FH {2! Height No. 2. etc. etc. FT NFC! Timeof completion must = RTvalue on Card IV. FH NFC! Total height of structure abovefoundation must = H on Card I. * Sameas for Option{2! set of cards Option ! cardsfollow Option ! cards. Column Variable FT NFB! Timeof completionmust = RTvalue on Card IV. FH NFB! Must = total height of structure = H on Card I above foundation. VI. Heat Generation Function F10.0,215! Column Variable 1-10 CEM Numberof pounds of cementper cubic yard of concrete {if blank, no heat generation function formulated!. 11 - 20 POZ Number of pounds of pozxolan per cubic yard of concrete. 21 - 25 Option A: 1: Type I cement heat generation average!. Option B.' 2: Type II cementheat generation average!. Option C: 3: Type II higher than averageheat generation. 185 Column Variable Descri tion 26- 29 Option D: 0: No modifications to internal program heat generation functions. 30 Option E: 1: Modifications made to internal heat generation functions. VII. Modification Factors 3FS.O! No cards if Option D. One card if Option E. Blank card if no modification.! F 1 ! Decimal factor multiplication of heat rate function Number l. 6 10 F 1 ! Decimal factor multiplication of heat r+e function Number 2. etc. 56- 60 Fl 2! Function number appears as 0.0 on output, but is assumed to be .0001~CEM + POZ/2 before modifi.cation 6l 65 F 1 3! made. Note: On first run through,'no modification need be made. Heat rate functions are printed out so future adjustments can be made if necessary. 186 APPENDIX M: INTERFACE INSTRUCTIONS PROGRAMS TEMP AND DETECT As is described in Chapter 5, program TEMPwas written to provide input, based upon commonvariables found in a tremie concrete placement, to the finite- element program, DETECT,which does the actual temperature calculations. Below are instructions which indicate how the output from program TEMP interfaces with program DETECT. Additional information on program DETECTmay be found in Polivka and Wilson's description of the program Reference 33!. I Source I Numbeof Program I ~ Must Indiv. Cards "TEMP" y Punch I. Problem Initiation and Title 1 I II. Master Control Card 1 *Partial I Info. I I III. Nodal Point Coordinates > As many as v ~ number of 1 , nodes. I IV. Boundary Condition Functions I I A. Control Information «Partial Check Info. I B. Time Function Data ! 3 Heat Gen. > I Values Function ~ 1! Any Additional l Boundary Value I I Functions I I V. ' Nodal Point Boundary Conditions As many as ' specified I IV A! ' 1 I I I VI. Element Specification ~e 1 - A. Control Information 1 Check B. Material Properties One for each Cards Information material- supplied I 1. concrete with 1 6 I 2. foundation 2 punched, I 187 Source I Number of Program I Must Indiv. Cards ~ ITEMPII I Punch C. Element Data I As many as i number of ~ elements. I Type 2 - A. Control Information B. Element Data ! As many as ~ required. 1I Type 3 Cooling Pipe Elements None Required I I VII. Solution Time Span Data I A. Lift Data Control Cards !Nu ber of , cards speci- efied on II!.' I B, Initial Conditions I As speci- fied on I VI I A! I to follow I a card. VIII. New Problem Data Same as I through VII. IX. Termination Card "STOP" 188 APPENDIX N: SAMPLE OUTPUT PROGRAMS TEMP AND DETECT 1. Figures N-I through N-5 present samples of output from Programs TEMP and DETECT which are described in Chapter 5, 2. The output from Program TEMP shows the automatic grid generation and the constant rate of concrete production options. The geometry of the placement is that shown in Figure i86 of Chapter 5. !io~N gOPyONLY ~AriOe 189 C Q IIJ V IZQ. C U! NV! Q aor LIJ IZ N IX ~ CCC >WW b. tJ~ Ih IW Z ~~P X g WD W0 pDWQ EVIL.r a0 W 4 &ON!g 0I OO Ih cf 8 ~ ~ ~ ~ 0 NO 0I ~ WC 4 00 M 00 aJ 0' lJ 0I II II II II 0 0 5 ~ ~ ~ ~ ~ IIJ LIJ I0 g P lg W 0! X X XI~r U gl ZZ 0 I- 8 '7 I 4 t0 Q V! 00 ~Z 0 00 PQ 0 Q. U 0 C4 0 r A LIJ C4 Cl th ~ 0 LIJI- LIJ iJ 4' LIII~I W LJ IIJ 'JJ ' Ir9gl 00 ~ Ll. 'J~ + 'JJ 4 LLI 3 >C Ch 0 3 OCr ~C gP ~ ~ ~ IJJQ 4rIN ! i!~ Jl I I Z ! J R II 0 II c[ 'l LJau a Q 'PT IJ VZ~~> !C > 2'M- w n UI- W Wr rI P TT. Z7'.0 IP I 0 LLILJ ? wW IJ r[ m Elg tl g LJ V 190 ZCI IK LU Z IU 0 I LU X 0 LU 0 L' uc LU IIII 0 aa CtK 0N X A fG I! VU P4 '0 I w IX tR 0 ~ Id LU bb Cl In 0 Cl 0 Lo. '4 4! Vl III V QO LU CQg b0 v 4 QoOOOOOOOOOO ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 4 j.O N<~NONaODOOO ~O.' I et+ g IU ILl za I I I I I I «««««+ &«I«t%& aa« I««~&la««~gaga% ««M«« t% COIljdNghhjjjP 5 hijjl9114dblO14t «Fihjhjij«OhtAA, PK O«CILRP!dLjj4hhjjj <««Ngdlhijj4hjjjcjj&O«CgAPjdjjjI 'Wg ~ i ~ ~ ~ ~ i ~ ~ ~ i ~ ~ ~ ~ ~ ~ ~ ~ ~ 1 i t ~ ~ ~ ~ ~ ~ ~ ~, ~ ~ ~ Ci O. I '««««~«««I«««««CVLLINAf AINCV Z g vQvvvvvvv'iar vvvvvv MvvvV'v vvvvvvvvvv Ljj I Lti th0 h hLjj Ijj ijj d 4 P!tij «!«0 5 Chjj5h h 4g Ljjd 8 A N««0 Ch5 ILLI ILI Cj h C Ljj d g N «O Q e h e e d e «O e Cj r e e d m Cu«O g e e e e i 4J Ij ILL ~ ~y ~~ ',~~ ~0 $8~ ~~I~ ~~ I~~ ~~ ~~ ~~ ~~ ~ ~~ 0~ i~ 4 LLjl-0«RLflht7 «6IjjhglO8d.4COONIdILLh g~tij!flh 0I«Y! d4 bOW j 0 0 ? '5 >u ~jsa«««,««ra«~ ««,«m«««« ~««+ra «««««« 0 4 0 2 Ijj 4 d N0ihjjjn.«>hjjjMOaj e~ eue eed «Lj h IIjm 0 hew' A IO a v « 0 «AI P!ndijj4t I IL'0 O««LLI~djjjijj4hCCOO O«nlhlhdijj ~ ~ i ~ ~ ~ ~ 1 + ~ I ~ ~ ~ ~ ~ t,' ~ y ~ ~ ig ~ ~ ~ ~ ~ ~ t ' ~ ~ ~ ~, Ljj C 0 «««« I«««««««««hl OI g g g 5 N 4!J >I 192 I ~2 yPI g~ i Cp r' O4, xo' QXi VI QD Cl Q. I II.' XI IIJ - 0J w i I o5 "i ! LIJIIJ ~ «ia, < Z LIJ ' ~ JI 0J « ~ I > ee «h 4O ah ole aN a IJJ ~ ~ ' 0J ~ r ~ I-a~ IJI 0J O a ZN 0 VJ ljl se + IIJ h te + Ifl Cl' ~ A ~ I~ HI N 0J a W IIJ IIJ ! ~ l ~ 0 a O.e g M IL,' X .ey N t «tN' J 0 00 Clh IOIe +N i IO 0 OO I I' ~ l0J ~ al IIJ ~ ~ ' VI IA I0J ~ I ~I O ghA] ; ~ 0 QOJA IJJ 0l i r,, O' , IJJ lti Pll V X he N >II II. 2 N Al I I h, g,',~ ! C VI .0J O UI 0JI ILI.VI ~! IIIJ 4h ,4N QK IIJ X e' ~ IN ~ Z 0J OiI ~ «'la 7 IJJ J * ~ l ~ 2 LU O CI « ~ ~ 4 N 0l I IJI h Ne I v ! VI ] ~t ~ ~; g 7I e ~ P! ~ 0J ~ c5 II! 193 x I h.' h! N K hlh; Ofh! P! OOO OOO ooa Oae 4 +4 +++ +++ +++ W LULU W LUW LLILU LU LLILLl LU eh!V e'!I! V» W IIILU Opwf gdP! Olf!V hC! hl Q P!LI! ao P! hl Off!e P! IPP CV ooa a&% 0! O' lf' IC! Lnr,o CL!hb If! LnLn Lf! !L!» b! M 4J O+ If! IO ~ LC I! h . Lf!tALf! If!%» !LI ~ e ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ 0 N W g 4J CJ O ! 0WoaA bb 0 4' ! m U » PC! If!» P!g Lf!4 h I -C!' 9 If!»1 ~P! I If! 4l ~ . Hh! P!P! V It! If! !f!C Pl Pf V ~ 'L!-! 0 0 0 m bb e c h!Nhf Nh!h! Ol h!hf hf hf h! H LUghlh!N O I OOO4lOOO ooo oaa 4J +++ +++/++0 +++ +++ 000! WOW W LULU LULULU LULL!uJ d! If! hP! hl Co V »Pl V ma Ie OO !C!CP I, g' CVh OP! hilt If! 4O 4 hlf! g 4 b! O' Oft OOC! V V ho l hf In !I! Pwua! NA V Lf! V lf, lf! e Ic y e Ln »LPP! bb a! IC!If! If! In lf! Ifl 9 lf} S Ln » Ch LC! 0 4 ! ~ ~ ~ ~ 0 ~ ~ !LI $ ~ ~ t ~ b~ ~ S4 > -Im Il 4 !f' V o $ h! Ie V 4 C e IL! e O'Ln m » h!CJ r!P! 194 FEDERALLY COORDINATED PROGRAM FCP! OF HIGH%'AY RESEARCH AND DEVELOPMENT The Offices of Researchand Development R&D! of the qualityof the humanenviron nent.The goals the FederalHighway Administration FHWA! are are reduction o adverse highway and traffic responsiblefor a broadprogram of staffand contract impacts,and protectionand enhancement of the research and development and a Federal-aid environment. program,conducted by or tht.oughthe Statehighway transportationagencies, that includesthe Highway Improved Materials Planningand Research HP&R! programand the Durability National CooperativeHighway ResearchProgram Materia!s R&D is concernedwith expandingthe NCHRP!managed by the TransportationResearch knowledgeand technologyof materialsproperties, Board.The FCP is a carefullyselected group of proj- using availab!enatural materials,improving struc- ects that uses research and development resources to tural foundation materials, recycling highway obtain timely solutions to urgent national highway materials,converting industrial wastesinto useful engineeringproblems.' highway products, developing extender or The diagonaldouble stripe on the coverof thisreport substitute materials for those in short supply, and representsa highwayand is color-codedto identify deve!oping more rapid and reliable testing the FCP categorythat the report falls under. A red procedures.The goalsare lower highwaycon- stripeis usedfor category1, dark blue for category2, struction costs and extended inaintenance-free light bluefor category3, brownfor category4, gray operation for category5, green for categories6 and.7, and an IgnprovedDesign to ReduceCosts, Extend orangestripe identifies category 0. Life Expectancy, and Insure Structural FCP CategoryDescriptiorga Safety Structural R&D is concerned with furthering the I. Improved Highway Design and Operation latest technological advancesin structural and for Safety hydraulic designs,fabrication processes,and SafetyR&D addressesproblems associated with constructiontechniques to provide safe, efficient the responsibilitiesof the FHWA under the highwaysat reasonablecosts. HighwaySafety Act andincludes investigation of appropriatedesign standards, roadside hardware, 6. Improved Technology for Highway signing,and physicaland scientificdata l'or the Construction formulation o improvedsafety regulations. This categoryis concernedwith the research, development, and implementation of highway 2. Reduction of Traffic Congestion, and constructiontechnology to increaseproductivity, ImprovedOperational Efficiency reduceenergy consumption, conserve dwindling Traffic R&D is concerned with increasing the resources,and reduce costswhi!e improving the operationalefficiency of existinghighways by quality and methodsof construction. advancingtechnology, by improvingdesigns for existingas wel! as new facilities, and by balancing 7. Improved Technology for Highway the demandwapacityrelationship through traffic Maintenance managementtechniques such as busand carpool This categoryaddresses prob!ems in preserving preferentialtreatment, motorist information, and the Nation's highwaysand includes activities in rerouting of tral'fic. physics! maintenance,traffic services,manage- $. Environmental Considerations in Highway ment, and equipment.The goal is to maximize Design,Location, Construction, and Opera- operationalefficiency and safetyto the traveling public while conserving resources. tion Environmental R&D is directed toward identify- 0. Other New Studies ing and evaluatinghighway elements that affect This category,not included in the seven.volume vThe complete seven volume o finial statement o the FCP is available from officia! statelnent of the FCP, is concerned with the NationalTechnical In ormationService, Springfield, Va. 22161. Single HP&R and NCHRPstudies not specificallyrelated copiesof theintroductory volume ate availab1e ndthout charge from Program to FCP projects.These studies involve R&D AnalysisQ RD-3hOffices>f Research and Development, Federal Highway Administration,washington, D.C. 20590. supportof otherFHWA program office research. N .Q T ! 0,20i30! >N PRINT 207 1 {C TO 20 PR ltd I 2t!l 2 GC 1 Pill t«1 2078 PR it,1 2100 « V I P>l ERR «RT C ALL I I