DOCSLIB.ORG

Alkali-Aggregate Reactivity (Aar) Facts Book

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Alkali-Aggregate Reactivity (Aar) Facts Book ALKALI-AGGREGATE REACTIVITY (AAR) FACTS BOOK 1. Report No. 2. Government Accession No. 3. Recipient’s Catalog No. FHWA-HIF-13-019 4. Title and Subtitle 5. Report Date March 2013 Alkali-Aggregate Reactivity (AAR) Facts Book 6. Performing Organization Code 7. Author(s) 8. Performing Organization Report No. Thomas, M.D.A., Fournier, B., Folliard, K.J. 9. Performing Organization Name and Address 10. Work Unit No. The Transtec Group, Inc. 6111 Balcones Drive Austin, TX 78731 11. Contract or Grant No. DTFH61-06-D-00035 12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered Office of Pavement Technology Final Report March 2013 Federal Highway Administration 1200 New Jersey Avenue, DE Washington, DC 20590 14. Sponsoring Agency Code 15. Supplementary Notes Contracting Officer’s Representative (COR): Gina Ahlstrom, HIAP-10 16. Abstract This document provides detailed information on alkali-aggregate reactivity (AAR). It primarily discusses alkali-silica reaction (ASR), cover­ ing the chemistry, symptoms, test methods, prevention, specifications, diagnosis and prognosis, and mitigation. Alkali-carbonate reaction (ACR) is also addressed. 17. Key Words 18. Distribution Statement Alkali-silica reactivity, alkali-aggregate reaction, reactive No restrictions. This document is available to the public through the Na­ aggregates, ASR, concrete durability, symptoms, identifica­ tional Technical Information Service, Springfield, VA 22161. tion, prevention, mitigation, lithium 9. Security Classif. (of this 20. Security Classif. (of this 21. No of Pages 22. Price report) page) 211 SI* (MODERN METRIC) CONVERSION FACTORS APPROXIMATE CONVERSIONS TO SI UNITS Symbol When You Know Multiply By To Find Symbol LENGTH in inches 25.4 millimeters mm ft feet 0.305 meters m yd yards 0.914 meters m mi miles 1.61 kilometers km AREA in2 square inches 645.2 square millimeters mm2 ft2 square feet 0.093 square meters m2 yd2 square yard 0.836 square meters m2 ac acres 0.405 hectares ha mi2 square miles 2.59 square kilometers km2 VOLUME fl oz fluid ounces 29.57 milliliters mL gal gallons 3.785 liters L ft3 cubic feet 0.028 cubic meters m3 yd3 cubic yards 0.765 cubic meters m3 NOTE: volumes greater than 1000 L shall be shown in m3 MASS oz ounces 28.35 grams g lb pounds 0.454 kilograms kg T short tons (2000 lb) 0.907 megagrams (or "metric ton") Mg (or "t") TEMPERATURE (exact degrees) oF Fahrenheit 5 (F-32)/9 Celsius oC or (F-32)/1.8 ILLUMINATION fc foot-candles 10.76 lux lx fl foot-Lamberts 3.426 candela/m2 cd/m2 FORCE and PRESSURE or STRESS lbf poundforce 4.45 newtons N lbf/in2 poundforce per square inch 6.89 kilopascals kPa APPROXIMATE CONVERSIONS FROM SI UNITS Symbol When You Know Multiply By To Find Symbol LENGTH mm millimeters 0.039 inches in m meters 3.28 feet ft m meters 1.09 yards yd km kilometers 0.621 miles mi AREA mm2 square millimeters 0.0016 square inches in2 m2 square meters 10.764 square feet ft2 m2 square meters 1.195 square yards yd2 ha hectares 2.47 acres ac km2 square kilometers 0.386 square miles mi2 VOLUME mL milliliters 0.034 fluid ounces fl oz L liters 0.264 gallons gal m3 cubic meters 35.314 cubic feet ft3 m3 cubic meters 1.307 cubic yards yd3 MASS g grams 0.035 ounces oz kg kilograms 2.202 pounds lb Mg (or "t") megagrams (or "metric ton") 1.103 short tons (2000 lb) T TEMPERATURE (exact degrees) oC Celsius 1.8C+32 Fahrenheit oF ILLUMINATION lx lux 0.0929 foot-candles fc cd/m2 candela/m2 0.2919 foot-Lamberts fl FORCE and PRESSURE or STRESS N newtons 0.225 poundforce lbf kPa kilopascals 0.145 poundforce per square inch lbf/in2 *SI is the symbol for the International System of Units. Appropriate rounding should be made to comply with Section 4 of ASTM E380. (Revised March 2003) Table of Contents 1 – Introduction .............................................................................................................................1 1.1 DEFINITIONS.....................................................................................................................1 1.2 HISTORY OF AAR.............................................................................................................2 1.3 AAR TODAY .......................................................................................................................4 REFERENCES ..........................................................................................................................8 2 – Fundamentals of Alkali-Silica Reaction................................................................................9 2.1 INTRODUCTION ...............................................................................................................9 2.2 CHEMISTRY OF THE REACTION ..............................................................................10 2.3 MECHANISM OF EXPANSION ....................................................................................13 2.4 REACTIVE SILICA .........................................................................................................15 2.4.1 Types of Reactive Silica ...............................................................................................15 2.4.2 Effect of Aggregate Size ...............................................................................................18 2.4.3 Pessimum Effect ........................................................................................................... 20 2.5 SOURCES OF ALKALI ...................................................................................................22 2.5.1 Pore Solution Composition ...........................................................................................22 2.5.2 Threshold Alkali Contents ............................................................................................25 2.5.3 Alkali Recycling ........................................................................................................... 27 2.6 ROLE OF MOISTURE.....................................................................................................29 REFERENCES ........................................................................................................................31 3 – Symptoms of Alkali-Silica Reaction (ASR).........................................................................35 3.1 INTRODUCTION .............................................................................................................35 3.2 CRACKING .......................................................................................................................35 3.3 EXPANSION CAUSING MOVEMENTS AND DEFORMATIONS...........................40 3.4 POP-OUTS .........................................................................................................................43 3.5 SURFACE DEPOSITS (GEL EXUDATION VS. EFFLORESCENCE).....................45 REFERENCES ........................................................................................................................46 4 – Test Methods..........................................................................................................................47 4.1 INTRODUCTION .............................................................................................................47 4.2 ASR TEST METHODS FOR EVALUATING AGGREGATE REACTIVTY ...........47 4.2.1 ASTM C 295: Standard Guide for Petrographic Examination of Aggregates for Con­ crete........................................................................................................................................ 48 4.2.2 ASTM C 289: Standard Test Method for Potential Alkali-Silica Reactivity of Aggre­ gates (Chemical Method) ....................................................................................................... 50 4.2.3 ASTM C 227: Standard Test Method for Potential Alkali Reactivity of Cement- Aggregate Combinations (Mortar-Bar Method) .................................................................... 51 4.2.4 AASHTO T 303 (ASTM C 1260): Standard Test Method for Potential Alkali Reactiv­ ity of Aggregates (Mortar-Bar Method) ................................................................................ 51 4.2.5 ASTM C 1293: Standard Test Method for Concrete Aggregates by Determination of Length Change of Concrete Due to Alkali-Silica Reaction ................................................... 54 4.3 ASR TEST METHODS FOR EVALUATING PREVENTIVE MEASURES ............ 58 4.3.1 ASTM C 441: Standard Test Method for Effectiveness of Mineral Admixtures or Ground Blast-Furnace Slag in Preventing Excessive Expansion of Concrete Due to the Al­ kali-Silica Reaction ................................................................................................................ 59 4.3.2 ASTM C 1567: Standard Test Method for Determining the Potential Alkali-Silica Re­ activity of Combinations of Cementitious Materials and Aggregate (Accelerated Mortar-Bar Method).................................................................................................................................. 61 4.3.3 ASTM C 1293: Standard Test Method for Concrete Aggregates by Determination of Length Change of Concrete Due to Alkali-Silica Reaction ................................................... 63 4.3.4 Other ASR Test Methods.............................................................................................. 64 4.4 ACR TEST METHODS FOR EVALUATING AGGREGATE REACTIVITY......... 66 4.5 SUMMARY.......................................................................................................................
Load more

Recommended publications
  • History of the Chlor-Alkali Industry
    2 History of the Chlor-Alkali Industry During the last half of the 19th century, chlorine, used almost exclusively in the textile and paper industry, was made [1] by reacting manganese dioxide with hydrochloric acid 100–110◦C MnO2 + 4HCl −−−−−−→ MnCl2 + Cl2 + 2H2O (1) Recycling of manganese improved the overall process economics, and the process became known as the Weldon process [2]. In the 1860s, the Deacon process, which generated chlorine by direct catalytic oxidation of hydrochloric acid with air according to Eq. (2) was developed [3]. ◦ 450–460 C;CuCl2 cat. 4HCl + O2(air) −−−−−−−−−−−−−−→ 2Cl2 + 2H2O(2) The HCl required for reactions (1) and (2) was available from the manufacture of soda ash by the LeBlanc process [4,5]. H2SO4 + 2NaCl → Na2SO4 + 2HCl (3) Na2SO4 + CaCO3 + 2C → Na2CO3 + CaS + 2CO2 (4) Utilization of HCl from reaction (3) eliminated the major water and air pollution problems of the LeBlanc process and allowed the generation of chlorine. By 1900, the Weldon and Deacon processes generated enough chlorine for the production of about 150,000 tons per year of bleaching powder in England alone [6]. An important discovery during this period was the fact that steel is immune to attack by dry chlorine [7]. This permitted the first commercial production and distribu- tion of dry liquid chlorine by Badische Anilin-und-Soda Fabrik (BASF) of Germany in 1888 [8,9]. This technology, using H2SO4 for drying followed by compression of the gas and condensation by cooling, is much the same as is currently practiced. 17 “chap02” — 2005/5/2 — 09Brie:49 — page 17 — #1 18 CHAPTER 2 In the latter part of the 19th century, the Solvay process for caustic soda began to replace the LeBlanc process.
    [Show full text]
  • Suppression Mechanisms of Alkali Metal Compounds
    SUPPRESSION MECHANISMS OF ALKALI METAL COMPOUNDS Bradley A. Williams and James W. Fleming Chemistry Division, Code 61x5 US Naval Research Lnhoratory Washington, DC 20375-5342, USA INTRODUCTION Alkali metal compounds, particularly those of sodium and potassium, are widely used as fire suppressants. Of particular note is that small NuHCOi particles have been found to be 2-4 times more effective by mass than Halon 1301 in extinguishing both eountertlow flames [ I] and cup- burner flames [?]. Furthermore, studies in our laboratory have found that potassium bicarbonate is some 2.5 times more efficient by weight at suppression than sodium bicarhonatc. The primary limitation associated with the use of alkali metal compounds is dispersal. since all known compounds have very low volatility and must he delivered to the fire either as powders or in (usually aqueous) solution. Although powders based on alkali metals have been used for many years, their mode of effective- ness has not generally been agreed upon. Thermal effects [3],namely, the vaporization of the particles as well as radiative energy transfer out of the flame. and both homogeneous (gas phase) and heterogeneous (surface) chemistry have been postulated as mechanisms by which alkali metals suppress fires [4]. Complicating these issues is the fact that for powders, particle size and morphology have been found to affect the suppression properties significantly [I]. In addition to sodium and potassium, other alkali metals have been studied, albeit to a consider- ably lesser extent. The general finding is that the suppression effectiveness increases with atomic weight: potassium is more effective than sodium, which is in turn more effective than lithium [4].
    [Show full text]
  • Alkali-Silica Reactivity: an Overview of Research
    SHRP-C-342 Alkali-Silica Reactivity: An Overview of Research Richard Helmuth Construction Technology Laboratories, Inc. With contributions by: David Stark Construction Technology Laboratories, Inc. Sidney Diamond Purdue University Micheline Moranville-Regourd Ecole Normale Superieure de Cachan Strategic Highway Research Program National Research Council Washington, DC 1993 Publication No. SHRP-C-342 ISBN 0-30cL05602-0 Contract C-202 Product No. 2010 Program Manager: Don M. Harriott Project Maxtager: Inam Jawed Program AIea Secretary: Carina Hreib Copyeditor: Katharyn L. Bine Brosseau May 1993 key words: additives aggregate alkali-silica reaction cracking expansion portland cement concrete standards Strategic Highway Research Program 2101 Consti!ution Avenue N.W. Washington, DC 20418 (202) 334-3774 The publicat:Lon of this report does not necessarily indicate approval or endorsement by the National Academy of Sciences, the United States Government, or the American Association of State Highway and Transportation Officials or its member states of the findings, opinions, conclusions, or recommendations either inferred or specifically expressed herein. ©1993 National Academy of Sciences 1.5M/NAP/593 Acknowledgments The research described herein was supported by the Strategic Highway Research Program (SHRP). SHRP is a unit of the National Research Council that was authorized by section 128 of the Surface Transportation and Uniform Relocation Assistance Act of 1987. This document has been written as a product of Strategic Highway Research Program (SHRP) Contract SHRP-87-C-202, "Eliminating or Minimizing Alkali-Silica Reactivity." The prime contractor for this project is Construction Technology Laboratories, with Purdue University, and Ecole Normale Superieure de Cachan, as subcontractors. Fundamental studies were initiated in Task A.
    [Show full text]
  • Silica Fume As a Scm for Pervious Concrete
    THE EFFECTS OF UTILIZING SILICA FUME IN PORTLAND CEMENT PERVIOUS CONCRETE A THESIS IN Civil Engineering Presented to the Faculty of the University of Missouri-Kansas City in partial fulfillment of the requirements for the degree MASTER OF SCIENCE By DANIEL ALLEN MANN B.S. University of Missouri-Kansas City, 2012 Kansas City, Missouri 2014 © 2014 DANIEL ALLEN MANN ALL RIGHTS RESERVED THE EFFECTS OF UTILIZING SILICA FUME IN PORTLAND CEMENT PERVIOUS CONCRETE Daniel Allen Mann, Candidate for the Master of Science Degree University of Missouri-Kansas City, 2014 ABSTRACT Silica fume has long been used as a supplementary cementing material to provide a high density, high strength, and durable building material. Silica fume has a particle size a fraction of any conventional cement, which allows it to increase concrete strength by decreasing the porosity especially near the aggregates surface. Because Portland Cement Pervious Concrete (PCPC) has a smaller bond area between aggregate and paste, silica fume has significant impacts on the properties of the PCPC. The research in this paper studies the workability of a cement paste containing silica fume in addition to analyzing the results of testing on Portland Cement Pervious Concrete mixtures that also contained silica fume. Testing conducted included a study of the effects of silica fume on cement’s rheological properties at various dosage rates ranging from zero to ten percent by mass. It was determined that silica fume has negligible effects on the viscosity of cement paste until a dosage rate of five percent, at which point the viscosity increases rapidly. In addition to the rheological testing of the cement paste, trials were also conducted on the pervious concrete samples.
    [Show full text]
  • Microstructural and Compressive Strength Analysis for Cement Mortar with Industrial Waste Materials
    Available online at www.CivileJournal.org Civil Engineering Journal Vol. 6, No. 5, May, 2020 Microstructural and Compressive Strength Analysis for Cement Mortar with Industrial Waste Materials Zahraa Fakhri Jawad a, Rusul Jaber Ghayyib a, Awham Jumah Salman a* a Al-Furat Al-Awsat Technical University, Najaf, Kufa, Iraq. Received 06 December 2019; Accepted 02 March 2020 Abstract Cement production uses large quantities of natural resources and contributes to the release of CO2. In order to treat the environmental effects related to cement manufacturing, there is a need to improve alternative binders to make concrete. Accordingly, extensive study is ongoing into the utilization of cement replacements, using many waste materials and industrial. This paper introduces the results of experimental investigations upon the mortar study with the partial cement replacement. Fly ash, silica fume and glass powder were used as a partial replacement, and cement was replaced by 0%, 1%, 1.5%, 3% and 5% of each replacement by the weight. Compressive strength test was conducted upon specimens at the age of 7 and 28 days. Microstructural characteristic of the modified mortar was done through the scanning electron microscope (SEM) vision, and X-ray diffraction (XRD) analysis was carried out for mixes with different replacements. The tests results were compared with the control mix. The results manifested that all replacements present the development of strength; this improvement was less in the early ages and raised at the higher ages in comparison with the control specimens. Microstructural analysis showed the formation of hydration compounds in mortar paste for each replacement. This study concluded that the strength significantly improved by adding 5% of silica fume compared with fly ash and glass powder.
    [Show full text]
  • How to Make Concrete More Sustainable Harald Justnes1
    Journal of Advanced Concrete Technology Vol. 13, 147-154, March 2015 / Copyright © 2015 Japan Concrete Institute 147 Scientific paper How to Make Concrete More Sustainable Harald Justnes1 A selected paper of ICCS13, Tokyo 2013. Received 12 November 2013, accepted 16 February 2015 doi:10.3151/jact.13.147 Abstract Production of cement is ranking 3rd in causes of man-made carbon dioxide emissions world-wide. Thus, in order to make concrete more sustainable one may work along one or more of the following routes; 1) Replacing cement in con- crete with larger amounts of supplementary cementing materials (SCMs) than usual, 2) Replacing cement in concrete with combinations of SCMs leading to synergic reactions enhancing strength, 3) Producing leaner concrete with less cement per cubic meter utilizing plasticizers and 4) Making concrete with local aggregate susceptible to alkali silica reaction (ASR) by using cement replacements, thus avoiding long transport of non-reactive aggregate. 1 Introduction SCMs, also uncommon ones like calcined marl 2. Replacing cement in concrete with combinations of The cement industry world-wide is calculated to bring SCMs leading to synergic reactions enhancing about 5-8% of the total global anthropogenic carbon strength dioxide (CO2) emissions. The general estimate is about 3. Producing leaner concrete with less cement per cubic 1 tonne of CO2 emission per tonne clinker produced, if meter utilizing plasticizers. fossil fuel is used and no measures are taken to reduce it. 4. Making concrete with local aggregate susceptible to The 3rd rank is not because cement is such a bad mate- alkali silica reaction (ASR) by using cement re- rial with respect to CO2 emissions, but owing to the fact placements, thus avoiding long transport of non- that it is so widely used to construct the infrastructure reactive aggregate and buildings of modern society as we know it.
    [Show full text]
  • Experimental Investigation of Self Healing Behavior of Concrete Using Silica Fume and GGBFS As Mineral Admixtures
    ISSN (Print) : 0974-6846 Indian Journal of Science and Technology, Vol 8(36), DOI: 10.17485/ijst/2015/v8i36/87644, December 2015 ISSN (Online) : 0974-5645 Experimental Investigation of Self Healing Behavior of Concrete using Silica Fume and GGBFS as Mineral Admixtures RA. B. Depaa* and T. Felix Kala Dr. MGR Educational and Research Institute University, Chennai - 600095, Tamil Nadu, India; [email protected], [email protected] Abstract The process of self-healing of concrete has been gaining momentum nowadays due to increased deterioration of concrete structures subjected to adverse environmental conditions. Admixtures like silica fume and ground granulated blast furnace slag is one of the self healing agents being experimented recently. The method of usage of Silica fume and ggbfs, the waste derivatives from coal and steel industries, strength and durability testing of these mixes for achieving the self healing prop- erty has been presented. The effects of self-healing on normal concrete by adding small amounts of GGBFS and silica fume to concrete is studied. For this purpose, silica fume is added to concrete at percent of 0%, 2.5%, 5%, 7.5%, 10%, 12.5% and cement has been replaced with GGBFS by 35% and 55% respectively. The adopted water binder ratio for silica fume specimensand GGBFS to mixes generate is 0.45. microcracks M30 mix designfor studying is being the done durability as per properties the Indian of Standard the specimens. Code IS: The 10262-1982. strength properties The specimens of con- are first tested for compressive strength at 28 days, then 70% and 90% of the compressive load is applied to another set of crete specimens made using silica fume and GGBFS are tested for compressive strength and the durability properties are studied using sorptivity index test.
    [Show full text]
  • Silica Fume and Metakaolin As Supplementary Cementing Materials- a Review
    ISSN(Online): 2319-8753 ISSN (Print): 2347-6710 International Journal of Innovative Research in Science, Engineering and Technology (A High Impact Factor, Monthly, Peer Reviewed Journal) Visit: www.ijirset.com Vol. 6, Issue 10, October 2017 Silica Fume and Metakaolin as Supplementary Cementing Materials- A Review Syed Abuthahir 1, Nirmalkumar2 P.G. Student, Department of Civil Engineering, Kongu Engineering College, Perundurai, Erode, India1 Professor, Department of Civil Engineering, Kongu Engineering College, Perundurai, Erode, India2 ABSTRACT:The replacement of cement by various mineral admixtures as supplementary cementing materials for concrete has gained a global attention in recent years. This replacement becomes efficient not only by increasing the strength and durability of the concrete but also reduces the usage of the ordinary cement thereby curtailing the environmental hazardous due to cement manufacturing industries. This paper reviews the work carried out on the use of silica fume (SF) and Metakaolin (MK) as supplementary cementing materials as a partial replacement for cement. The literature demonstrates that both SF and MK are effective and causes significant improvement in various properties of the concrete in both fresh and harden state. KEYWORDS: Metakaolin, Silica Fume, Compressive Strength, Durability Properties. I.INTRODUCTION Major of the construction company relies on the concrete. Cement is major constituent of concrete. The annual global production of ordinary portland cement is about 3 Gt. Cement becomes a dominant binder due to its versatility, durability, and its demand increases dramatically. Even though it is a vital material, it production directly affects the environment by releasing 0.87t of carbon dioxide for every tonne of cement produced.
    [Show full text]
  • Effect of Immersion in Water Or Alkali Solution on the Structures and Properties of Epoxy Resin
    polymers Article Effect of Immersion in Water or Alkali Solution on the Structures and Properties of Epoxy Resin Bin Wang 1, Dihui Li 2,3,4, Guijun Xian 2,3,4 and Chenggao Li 2,3,4,* 1 Central Research Institute of Building and Construction Co., Ltd., Beijing 100088, China; [email protected] 2 Key Lab of Structures Dynamic Behavior and Control, Ministry of Education, Harbin Institute of Technology, Harbin 150090, China; [email protected] (D.L.); [email protected] (G.X.) 3 Key Lab of Smart Prevention and Mitigation of Civil Engineering Disasters of the Ministry of Industry and Information Technology, Harbin Institute of Technology, Harbin 150090, China 4 School of Civil Engineering, Harbin Institute of Technology, Harbin 150090, China * Correspondence: [email protected]; Tel./Fax: +86-451-8628-3120 Abstract: The durability of fiber-reinforced polymer (FRP) composites is significantly dependent on the structures and properties of the resin matrix. In the present paper, the effects of physical or chemical interactions between the molecular chain of the epoxy resin matrix and water molecules or alkaline groups on the water absorption, mechanical structures, and microstructures of epoxy resin samples were studied experimentally. The results showed that the water uptake curves of the epoxy resin immersed in water and an alkali solution over time presented a three-stage variation. At different immersion stages, the water uptake behavior of the resin showed unique characteristics owing to the coupling effects of the solution concentration gradient diffusion, molecular hydrolysis reaction, and molecular segment movement. In comparison with the water immersion, the alkali solution environment promoted the hydrolysis reaction of the epoxy resin molecular chain.
    [Show full text]
  • Effect of Alkalies on Wool
    U. S. DEPARTMENT OF COMMERCE NATIONAL BUREAU OF STANDARDS RESEARCH PAPER RP810 Part of Journal of Research of the N.ational Bureau of Standards, Volume 15, July 1935 EFFECT OF ALKALIES ON WOOL By Milton Harris 1 ABSTRACT Data on the effect of various alkaline reagents on the physical and chemical properties of wool yarn are presented. When wool is treated with dilute sodium­ hydroxide solutions, a rapid splitting off of a portion of the sulphur occurs. On continued treatment, the sulphur content of the residual wool approaches a con­ stant value of about 1.8 percent. The results indicate that the alkaline treatment has changed a portion of the sulphur to a form which tends to resist further split­ ting from the molecule. Oxidizing and reducing agents attack the disulphide groups and make wool more susceptible to alkaline treatments. The susceptibil­ ity of untreated wool to alkaline reagents appears to be closely associated with the lability of its sulphur in alkaline solutions. CONTENTS Page I. Introduction________ _____ _______ _____ ____ _______ ____ ___________ 63 II. Materials and methods_ _ _ _ _ __ _ ___ _ _ _ _ __ __ _ __ _ __ ______ _________ __ 64 nI. Results and discussion___ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ _ __ _ _ _ _ _ _ __ _ _ _ _ _ _ 65 1. Effect of alkaline reagents on wool yarn___ __________ ________ 65 2. Nature of the action of alkalies on the sulphur of wooL_ __ ____ 66 3.
    [Show full text]
  • Investigation of Alkali-Silica Reactivity in Sustainable Ultrahigh Performance Concrete
    sustainability Article Investigation of Alkali-Silica Reactivity in Sustainable Ultrahigh Performance Concrete Safeer Abbas 1, Wasim Abbass 1, Moncef L. Nehdi 2,* , Ali Ahmed 1 and Muhammad Yousaf 1 1 Civil Engineering Department, University of Engineering and Technology Lahore, Lahore 54890, Pakistan; [email protected] (S.A.); [email protected] (W.A.); [email protected] (A.A.); [email protected] (M.Y.) 2 Department of Civil and Environmental Engineering, Western University, London, ON N6A 5B9, Canada * Correspondence: [email protected]; Tel.: +1-519-6612111 (ext. 88308) Abstract: Considering its superior engineering properties, ultrahigh performance concrete (UHPC) has emerged as a strong contender to replace normal strength concrete (NSC) in diverse construction applications. While the mechanical properties of UHPC have been thoroughly explored, there is still dearth of studies that quantify the durability of UHPC, especially for sustainable mixtures made with local materials. Therefore, this research aims at investigating the alkali-silica reactivity (ASR) potential in sustainable UHPC in comparison with that of NSC. Sustainable UHPC mixtures were prepared using waste untreated coal ash (CA), raw slag (RS), and locally produced steel fibers. UHPC and benchmark NSC specimens were cast for assessing the compressive strength, flexural strength, and ASR expansion. Specimens were exposed to two curing regimes: accelerated ASR conditions (as per ASTM C1260) and normal water curing. UHPC specimens incorporating RS achieved higher compressive and flexural strengths in comparison with that of identical UHPC specimens made with CA. ASR expansion of control NSC specimens exceeded the ASTM C1260 limits (>0.20% at Citation: Abbas, S.; Abbass, W.; 28 days).
    [Show full text]
  • United States Patent (19) | 1 || 3,975,503 Hauschild Et Al
    United States Patent (19) | 1 || 3,975,503 Hauschild et al. |45| Aug. 17, 1976 (54) METHOD FOR PRODUCING ALKAL 3.25.49.46 6/1966 Hass et al. .......................... 423f42 3644()89 2/ 1972 Minz et al........................... 423f4 CARBONATE 3,751.56() 8/1973 Neumann..... ... .42318.9 (75) Inventors: Ulrich Hauschild; Reimar Musall, 3,7739()2 11/1973 Neumann..... ... 42.3/421 both of Hannovcr; Hans-Jirgen 387 (),784 3/1975 Sueman............................... 4231431 Schröder, Pattensen, Hannover, all of Germany FOREIGN PATENTS OR APPLICATIONS 73,794 4/1968 Belgium.............................. 423/42 Assignee: Kali-Chemie Aktiengesellschaft, 229 3/1971 Japan..... ... 423f421 Hannover, Germany 2) 43 6/197l Japan..................... ... 4231421 89569() 5/1962 United Kingdom................. 423/42 Filcd: Dec. 13, 1974 Appl. No.: 532,365 Primary Examiner-Oscar R. Vertiz Assistant Examiner-Gary P. Straub Related U.S. Application Data Attorney, Agent, or Firn-Spencer & Kaye 63 Continuation of Ser. No. 436,719, Jan. 25, 1974, abandoned, which is a continuation of Ser. No. 204,058, Dec. 2, 1971, abandoned. 57) ABSTRACT A method for producing alkali carbonate crystals, in 3() Foreign Application Priority Data cluding adding to an alkali carbonate and alkali hy Dec. 8, 97 () Germany............................ 206()287 droxide solution stream a 10 to 75 weight-% alkali hy Aug. 27, 197 Germany............................ 243 ()()8 droxide solution, charging the resulting mixture into a CO-containing gas whose temperature is from 150 to 52) U.S. Cl.................................. 423/421; 423/189 700°C, collecting mixture remaining as liquid from the 51 int. Cl............................................ C01D 7/07 gas at the end of a residence time of mixture in gas of 58 Field of Search............................
    [Show full text]