Evaluating Air-Entraining Admixtures for Highway Concrete (2007)

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TRANSPORTAT ION RESEARCH BOARD WASHINGTON, D.C. 2007 www.TRB.org N A T I O N A L C O O P E R A T I V E H I G H W A Y R E S E A R C H P R O G R A M NCHRP REPORT 578 Subject Areas Materials and Construction Evaluating Air-Entraining Admixtures for Highway Concrete Mohamad A. Nagi Paul A. Okamoto A N D Ronald L. Kozikowski CONSTRUCTION TECHNOLOGY LABORATORIES, INC. Skokie, IL A N D Kenneth Hover CORNELL UNIVERSITY Ithaca, NY Research sponsored by the American Association of State Highway and Transportation Officials in cooperation with the Federal Highway Administration

NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM Systematic, well-designed research provides the most effective approach to the solution of many problems facing highway administrators and engineers. Often, highway problems are of local interest and can best be studied by highway departments individually or in cooperation with their state universities and others. However, the accelerating growth of highway transportation develops increasingly complex problems of wide interest to highway authorities. These problems are best studied through a coordinated program of cooperative research. In recognition of these needs, the highway administrators of the American Association of State Highway and Transportation Officials initiated in 1962 an objective national highway research program employing modern scientific techniques. This program is supported on a continuing basis by funds from participating member states of the Association and it receives the full cooperation and support of the Federal Highway Administration, United States Department of Transportation. The Transportation Research Board of the National Academies was requested by the Association to administer the research program because of the Board’s recognized objectivity and understanding of modern research practices. 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Published reports of the NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM are available from: Transportation Research Board Business Office 500 Fifth Street, NW Washington, DC 20001 and can be ordered through the Internet at: http://www.national-academies.org/trb/bookstore Printed in the United States of America NCHRP REPORT 578 Project 18-10 ISSN 0077-5614 ISBN: 978-0-309-09889-2 Library of Congress Control Number 2007930093 © 2007 Transportation Research Board COPYRIGHT PERMISSION Authors herein are responsible for the authenticity of their materials and for obtaining written permissions from publishers or persons who own the copyright to any previously published or copyrighted material used herein. Cooperative Research Programs (CRP) grants permission to reproduce material in this publication for classroom and not-for-profit purposes. 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The members of the technical committee selected to monitor this project and to review this report were chosen for recognized scholarly competence and with due consideration for the balance of disciplines appropriate to the project. The opinions and conclusions expressed or implied are those of the research agency that performed the research, and, while they have been accepted as appropriate by the technical committee, they are not necessarily those of the Transportation Research Board, the National Research Council, the American Association of State Highway and Transportation Officials, or the Federal Highway Administration, U.S. Department of Transportation. Each report is reviewed and accepted for publication by the technical committee according to procedures established and monitored by the Transportation Research Board Executive Committee and the Governing Board of the National Research Council. 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CRP STAFF FOR NCHRP REPORT 578 Christopher W. Jenks, Director, Cooperative Research Programs Crawford F. Jencks, Deputy Director, Cooperative Research Programs Amir N. Hanna, Senior Program Officer Eileen P. Delaney, Director of Publications Hilary Freer, Senior Editor NCHRP PROJECT 18-10 PANEL Field of Materials and Construction—Area of Concrete Materials David L. Rettner, American Engineering Testing, Inc., St. Paul, MN (formerly Minnesota DOT) (Chair) Daniel P. Johnston, South Dakota DOT, Pierre, SD John F. Adam, Iowa DOT, Ames, IA Ahmad A. Ardani, ARA Transportation, Littleton, CO (formerly Colorado DOT) David Z. Graves, New York State DOT, Albany, NY Aly A. Hussein, South Carolina DOT, Columbia, SC Donald J. Janssen, University of Washington, Seattle, WA Darmawan Ludirdja, ACT Lab Inc., Wayne, NJ Peter A. Kopac, FHWA Liaison Frederick Hejl, TRB Liaison AUTHOR ACKNOWLEDGMENTS The research reported herein was performed under NCHRP Project 18-10 by Construction Technol- ogy Laboratories, Inc. (CTL). Dr. Mohamad Nagi, Senior Engineer, was the principal investigator. The other authors of this report are Paul Okamoto and Ron Kozikowski of CTL, who participated in the lab- oratory testing and the statistical analysis of the collected data; and Dr. Kenneth Hover, Professor of Civil Engineering, Cornell University, who participated in the literature review and development of the experimental program. C O O P E R A T I V E R E S E A R C H P R O G R A M S

This report presents a recommended procedure for evaluating air-entraining admixtures used in highway concrete. The procedure involves the testing of non-air-entrained concrete and concrete containing the air-entraining admixture under simulated field conditions. Cri- teria are proposed for acceptance of admixtures for use in either highway pavements or structures. The recommended procedure and acceptance criteria will guide materials engi- neers in evaluating and selecting air-entraining admixtures that should contribute to appro- priate freeze-thaw durability and thus to good performance and long service life. The con- tent of the report will be of immediate interest to materials engineers, researchers, and others concerned with the design of concrete mixtures for use in highway pavements and structures. Extensive laboratory testing and long-term field experience have demonstrated conclu- sively that concrete must be properly air entrained if it is to resist the action of freezing and thawing. For more than 50 years, neutralized Vinsol resin has been used effectively for air entrainment. However, other air-entraining admixtures have been introduced in recent years and their use has increased primarily because of the higher cost and limited supply of Vinsol resin. Current test methods, such as AASHTO T 157, Air-Entraining Admixtures for Concrete, set limits on the effects that any given air-entraining admixture may exert on certain prop- erties of the fresh and hardened concrete mixture in comparison with a similar concrete mix- ture containing a standard-reference air-entraining admixture such as neutralized Vinsol resin. However, experience with bridge decks, pavements, and other highway structures that were constructed with concrete mixtures incorporating newer air-entraining admixtures indicated that current test methods do not accurately assess the impact of these newer admix- tures on concrete properties and durability. Thus, research was needed to address the issues associated with the use of these air-entraining admixtures in highway concrete and to develop recommendations to help improve specifications for air-entraining admixtures. Under NCHRP Project 18-10, “Procedures for Evaluating Air-Entraining Admixtures for Highway Concrete,” Construction Technology Laboratories, Inc., of Skokie, Illinois, worked with the objective of developing procedures for evaluating and qualifying air- entraining admixtures for hydraulic cement concrete for highway applications. To accom- plish this objective, the researchers conducted an extensive test program in which they examined the properties of concrete mixtures containing a variety of air-entraining admix- tures and related these properties to freezing and thawing durability. Based on analysis of test results, the researchers developed a procedure for evaluating air-entraining admixtures that involves the testing of non-air-entrained concrete and concrete containing the air- entraining admixture under simulated field conditions. Admixture evaluation is made by F O R E W O R D By Amir N. Hanna Staff Officer Transportation Research Board

comparing the results from these tests against proposed evaluation criteria. The procedure includes two protocols: one for evaluating admixtures intended for use in highway pave- ments and the other for evaluating admixtures intended for use in highway structures. Finally, validity of the recommended procedure was confirmed by laboratory tests con- ducted on concrete mixtures containing five air-entraining admixtures with known perfor- mance records. The recommended test method and proposed acceptance criteria will provide a good indicator of the expected concrete properties and resistance to freezing and thawing and can, therefore, be used to evaluate air-entraining admixtures intended for use in highway pavements and structures. The test method will be particularly useful to highway agencies and is recommended for consideration and adoption by AASHTO as a standard test method. Appendixes A through C contained in the research agency’s final report are not published herein. These appendixes are accessible on the web as NCHRP Web-Only Document 101 at http://www4.trb.org/trb/onlinepubs.nsf. These appendixes are titled as follows: Appendix A: Literature Review and Survey; Appendix B: Foam Drainage and Infrared Test Results; and Appendix C: Detailed Test Results

C O N T E N T S 1 Summary 3 Chapter 1 Introduction 3 Project Background 3 Objective and Scope of the Research 3 Research Approach 4 Factors Affecting Air-Entrainment 4 Statistical Analysis of Selected Factors 4 Development and Validation of New Procedures 5 Chapter 2 Background and Literature Search 5 Introduction 5 Mechanism of Air Entrainment 5 Effects of Air Entrainment on Properties of Concrete 6 Factors Affecting Air Entrainment 8 Identification and Evaluation of Test Procedures 9 Selection and Procurement of Air-Entraining Admixtures 9 Identification and Procurement of Admixtures 9 Testing of Admixtures 10 Selection of Admixtures for Laboratory Test 11 Experimental Program 13 Chapter 3 Analysis of Test Results 13 Concrete Properties 13 Compressive Strength 13 Flexural Strength 13 Air-Void Analysis 13 Strength Reduction Evaluation 13 Statistical Analysis 15 Factors Affecting Spacing Factor 19 Factors Affecting Strength 25 Effects of Air-Entraining Admixture Type on Strength 28 Chapter 4 Development of Air-Entraining Admixture Evaluation Process 28 Introduction 28 Performance Requirements 28 Testing Protocols 29 Validation of the Proposed Procedures 30 Properties of the Selected Admixtures 30 Test Results

35 Chapter 5 Summary of Findings and Suggested Research 35 Summary of Findings 35 Suggested Research 36 References 38 Attachment A: Recommended Method for Air-Entraining Admixtures for Highway Concrete and Standard Specification for Air-Entraining Admixtures for Highway Concrete