_STP_266-1960.pdf

SYMPOSIUM ON EFFECT OF WATER-REDUCING ADMIXTURES AND SET-RETARDING ADMIXTURES ON PROPERTIES OF CONCRETE Presented at the THIRD PACIFIC AREA NATIONAL MEETING AMERICAN SOCIETY FOR TESTING MATERIALS San Francisco,Calif.,October 14,I959 O Reg.U.S.Pat.Off.ASTM Special Technical Publication No.z66 Price 87.50;to Members$6.00 Published by the AMERICAN SOCIETY FOR TESTING MATERIALS I916 Race St.,Philadelphia 3,Pa.BY ARc,SOCIETY FOR TEsTO MATEma.S 1960 Library of Congress Catalog Card Number:60-9520 Printed in Baltimore,Md.June 196o FOREWORD The use of water-reducing admixtures and set retarders in concrete has grown continuously since their introduction over 25 years ago,with a present estimated usage in the production of 25 million cubic yards of concrete annually in the United States alone.Further indication of current interest is evidenced by the fact that ASTM Committee C-9 on Concrete and Con-crete Aggregates and certain public agencies are actively drafting standard methods of test and specifications to govern the purchase and performance requirements of these admixtures for concrete.The future of better concrete lies in an increased understanding of con-creting materials and the best manner of combining them to produce the maximum in strength and durability.It is with this in mind that Committee C-1 on Cement and Committee C-9 have jointly sponsored this Symposium,held during the Third Pacific Area National Meeting of the Society from October 11-16,1959,in San Francisco,Calif.The Symposium consisted of ten papers and a summary.It is of interest to note that four of the papers represent the joint contribution of four principal producers of admixtures.The remaining papers were prepared by repre-sentatives of consumer interests,research organizations and the cement industry.The Symposium was held during two sessions on Wednesday,October 14.Professors R.E.Davis and Milos Polivka,both of the University of Cali-fornia,presided over the two sessions respectively.The Joint Symposium Committee,representing Committees C-1 and C-9,included the following members:R.E.DAVIS,University of California(Chairman)W.C.HANNA,California Portland Cement Co.(Vice-Chairman)MILOS POLIVKA,University of California(Secretary)R.L.BLAINE,National Bureau of Standards JosEPH E.GY,National Crushed Stone Assn.E.C.HmGINSON,U.S.Bureau of Reclamation THOMAS B.KENNEDY,Corps of Engineers WnJ.IAM LERCH,Portland Cement Assn.W.J.McCoY,Lehigh Portland Cement Co.RICg_AI C.MILENZ,Master Builders Co.NoTE.-The Society is not responsible,as a body,for the statements and opinions advanced in this publication.CONTENTS PAGE Introduction-Bruce Foster.1 Actions of Calcium Sulfate and Admixtures in Portland Cement Pastes-W.C.Hansen.3 Discussion.25 Structural and Lean Mass Concrete as Affected by Water-Reducing,Set-Retarding Agents-George B.Wallace and EIwood L.Ore.38 Discussion.94 Observations in Testing and Use of Water-Reducing Retarders-Lewis H.Tuthill,Robert F.Adams,and John M.Heroine,Jr.97 Discussion.118 Effect of Water-Reducing Admixtures and Set-Retarding Admixtures as Influenced by Portland Cement Composition-Milos Polivka and Alexander Klein.124 Field Experience Using Water-Reducers in Ready-Mixed Concrete-E.L.Howard,K.K.Griflfiths,and W.E.Moulton.140 Discussion.148 Detection of Lignosulfonate Retarder in Cement Suspensions and Pastes-E.G.Swensen and T.Thorvaldson.159 Discussion.169 Introduction to Producers Papers on Water-Reducing Admixtures and Set-Retard-ing Admixtures for Concrete-M.E.Prior and A.B.Adams.170 Effect of Water-Reducing Admixtures and Set-Retarding Admixtures on the Prop-erties of Plastic Concrete-C.A.Vollick.180 The Effect of Water-Reducing Admixtures and Set-Retarding Admixtures on the Properties of Hardened Concrete-D.R.MacPherson and H.C.Fischer.201 Water-Reducing Admixtures and Set-Retarding Admixtures for Concrete:Uses;Specifications;Research Objectives-Richard C.Mielenz.218 Discussion.234 Summary-Bruce Foster.240 SYMPOSIUM ON EFFECT OF WATER-REDUCING ADMIXTURES AND SET-RETARDING ADMIXTURES ON PROPERTIES OF CONCRETE INTRODUCTION BY BRUCE FOSTER 1 Admixtures for portland cement con-crete are those ingredients which are added to the primary constituents(port-land cement,aggregates,and water)to(1)improve or modify the properties of the concrete,(2)compensate for some deficiency in a primary constituent,or(3)effect a reduction in cost.Some ma-terials which we class as admixtures,such as pozzolan and blood,were con-crete ingredients used by the Romans.Because the addition of another in-gredient is very likely to require addi-tional control and technical skill on the part of the concrete producer and in-spection agency,and extra facilities for handling and proportioning,and because admixtures in general were originally frowned upon by the cement and con-crete industries,these materials were for many years slow in gaining general ac-ceptance.However,the recognition of the role of entrained air in imparting frost resistance to concrete h