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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 589 Subject Areas Materials and Construction Improved Conditioning and Testing Procedures for HMA Moisture Susceptibility Mansour Solaimanian PENNSYLVANIA STATE UNIVERSITY University Park, PA Ramon F. Bonaquist ADVANCED ASPHALT TECHNOLOGIES, LLC Sterling, VA Vivek Tandon THE UNIVERSITY OF TEXAS AT EL PASO El Paso, TX 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 Boardâs recognized objectivity and understanding of modern research practices. The Board is uniquely suited for this purpose as it maintains an extensive committee structure from which authorities on any highway transportation subject may be drawn; it possesses avenues of communications and cooperation with federal, state and local governmental agencies, universities, and industry; its relationship to the National Research Council is an insurance of objectivity; it maintains a full-time research correlation staff of specialists in highway transportation matters to bring the findings of research directly to those who are in a position to use them. The program is developed on the basis of research needs identified by chief administrators of the highway and transportation departments and by committees of AASHTO. Each year, specific areas of research needs to be included in the program are proposed to the National Research Council and the Board by the American Association of State Highway and Transportation Officials. Research projects to fulfill these needs are defined by the Board, and qualified research agencies are selected from those that have submitted proposals. Administration and surveillance of research contracts are the responsibilities of the National Research Council and the Transportation Research Board. The needs for highway research are many, and the National Cooperative Highway Research Program can make significant contributions to the solution of highway transportation problems of mutual concern to many responsible groups. The program, however, is intended to complement rather than to substitute for or duplicate other highway research programs. 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 589 Project 9-34 ISSN 0077-5614 ISBN: 978-0-309-09906-6 Library of Congress Control Number 2007907446 © 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. Permission is given with the understanding that none of the material will be used to imply TRB, AASHTO, FAA, FHWA, FMCSA, FTA, or Transit Development Corporation endorsement of a particular product, method, or practice. It is expected that those reproducing the material in this document for educational and not-for-profit uses will give appropriate acknowledgment of the source of any reprinted or reproduced material. For other uses of the material, request permission from CRP. NOTICE The project that is the subject of this report was a part of the National Cooperative Highway Research Program conducted by the Transportation Research Board with the approval of the Governing Board of the National Research Council. Such approval reflects the Governing Boardâs judgment that the program concerned is of national importance and appropriate with respect to both the purposes and resources of the National Research Council. 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. The Transportation Research Board of the National Academies, the National Research Council, the Federal Highway Administration, the American Association of State Highway and Transportation Officials, and the individual states participating in the National Cooperative Highway Research Program do not endorse products or manufacturers. Trade or manufacturersâ names appear herein solely because they are considered essential to the object of this report.
CRP STAFF FOR NCHRP REPORT 589 Christopher W. Jenks, Director, Cooperative Research Programs Crawford F. Jencks, Deputy Director, Cooperative Research Programs Edward T. Harrigan, Senior Program Officer Eileen P. Delaney, Director of Publications Ellen M. Chafee, Assistant Editor NCHRP PROJECT 09-34 PANEL Field of Materials and ConstructionâArea of Bituminous Materials Timothy B. Aschenbrener, Colorado DOT (Chair) Phillip B. Blankenship, Asphalt Institute, Lexington, KY German J. Claros, Texas DOT Ronald Cominsky, Pennsylvania Asphalt Pavement Association Karl W. Frick, Oregon DOT Wade McClay, Freeport, ME Gale C. Page, Florida DOT Richard E. Root, Consultant, Scottsdale, AZ Judie Ryan, Wisconsin DOT John DâAngelo, FHWA Liaison Frederick Hejl, TRB Liaison AUTHOR ACKNOWLEDGMENTS The research reported herein was performed under NCHRP Project 9-34 by the Pennsylvania Trans- portation Institute at Pennsylvania State University, the University of Texas at El Paso, Advanced Asphalt Technologies, LLC, and PaveTex Engineering and Testing, Inc. The Pennsylvania Transportation Insti- tute was the primary contractor. Dr. Mansour Solaimanian, Director of the Northeast Center of Excellence for Pavement Technology at Pennsylvania State University, served as principal investigator for the project. Work at Advanced Asphalt Technologies, LLC, was performed under the direction of Dr. Ramon Bonaquist, Chief Operat- ing Officer, who also served as the project manager. Dr. Vivek Tandon, Associate Professor of Civil Engi- neering, University of Texas, El Paso, was responsible for the work performed at the University of Texas at El Paso. Mr. Maghsoud Tahmoressi, President, PaveTex Engineering and Testing, Inc., oversaw the work performed at PaveTex. Dr. Charles Antle, Professor Emeritus, Pennsylvania State University, pro- vided statistical advice to the research team. Several graduate students were involved with testing and contributed significantly to the success of this project. Dr. Ali Soltani was instrumental in providing the data acquisition program. Mr. Darin Hunter, Senior Technician at Pennsylvania State University, and David Fedor, former Pennsylvania State Univer- sity graduate student, made important contributions toward conducting the quality testing program for this research. 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 the findings of a research project to investigate whether combin- ing the environmental conditioning system with the simple performance test would pro- vide a superior procedure for determining the moisture susceptibility of hot-mix asphalt (HMA). The report will be of particular interest to materials engineers in state highway agencies, as well as to materials suppliers and paving contractor personnel who are respon- sible for the design and evaluation of HMA. Moisture susceptibility is a primary cause of distress in hot-mix asphalt (HMA) pave- ments. There is good evidence that moisture susceptibility is influenced by aggregate min- eralogy, aggregate surface texture, asphalt binder chemistry, and the interaction between asphalt binder and aggregate. The great number of different aggregate mineralogies and the numerous types of unmodified and modified asphalt binders used across the United States, coupled with varied environmental conditions, traffic levels, and construction practices, have made testing to accurately predict HMA moisture susceptibility a difficult task. Under NCHRP Project 9-34, âImproved Conditioning Procedure for Predicting the Moisture Susceptibility of HMA Pavements,â the Pennsylvania Transportation Institute was tasked with developing an improved method for determining the moisture susceptibility of HMA. The method would be based on the use of the Strategic Highway Research Program (SHRP) environmental conditioning system (ECS) combined with the dynamic modulus procedure developed as a simple performance test for HMA in NCHRP Projects 9-19 and 9-29; the measure of moisture susceptibility would be the ratio of dynamic modulus before conditioning to the dynamic modulus after conditioning in the ECS. At a minimum, the improved conditioning and testing procedure would be sensitive to the effects of normal variability in material and mix properties expected during laboratory mix design and field construction and exhibit acceptable levels of repeatability and reproducibility compared with current methods for moisture susceptibility testing. In Phase I of the project, Pennsylvania Transportation Institute evaluated the three HMA performance tests developed in NCHRP Project 9-19 and determined that the dynamic modulus test method combined with the ECS conditioning procedure provided the best accuracy and precision compared with ASTM D4867, Standard Test Method for Effect of Moisture on Asphalt Concrete Paving Mixtures. In the following Phase IA, a prelim- inary ECS/dynamic modulus method was applied to laboratory specimens prepared from materials used in the construction of eight pavements of known field moisture susceptibil- ity. The ECS/dynamic modulus procedure was shown to provide the best correlation with field performance compared with the results of both ASTM D4867 and the Hamburg wheel tracking test. However, despite this demonstrated ability to discriminate between mixes that F O R E W O R D By Edward T. Harrigan Staff Officer Transportation Research Board
perform well and mixes that perform poorly in resisting moisture damage, it is unlikely that the ECS/dynamic modulus procedure would be adopted for routine use in its present form. Specifically, further work would be needed to reduce the duration of water and load condi- tioning and to better define the temperature at the time of conditioning and the magnitude of the required conditioning load. This final report includes (1) detailed descriptions of the conditioning and test equip- ment, the laboratory experiments, and the data analysis procedures; (2) a discussion of the research results and their limitations; and (3) a summary of the key findings, conclusions, and recommendations. The following appendixes are available online at http://trb.org/news/ blurb_detail.asp?id=8113: Appendix A ECS/Dynamic Modulus Procedure for Phase IA Appendix B Test Specimen Identification and Air Void Content Appendix C HWTD Data and Graphs Appendix D ECS/Dynamic Modulus Results Appendix E Visual Inspection Appendix F Statistical Analysis of Dynamic Modulus Results.
C O N T E N T S 1 Summary 3 Chapter 1 Introduction and Research Approach 3 1.1 Background and Problem Statement 3 1.2 Laboratory Tests for Moisture Damage Prediction 4 1.3 Objective and Scope 5 1.4 Report Organization 6 Chapter 2 Experimental Program 6 2.1 Phase I Experimental Program and Findings 8 2.2 Phase IA Experiment Design 9 2.3 Materials Selection 10 2.4 Laboratory Testing Program 27 Chapter 3 Findings 27 3.1 Mix Design Verification 30 3.2 ASTM D4867 Results 41 3.3 The Hamburg Wheel Tracking Test 43 3.4 Dynamic Modulus Testing 52 3.5 Statistical Analysis of Dynamic Modulus Test Results 61 Chapter 4 Interpretation, Appraisal, and Applications 61 4.1 Interpretation of the Results 61 4.2 Appraisal of the ECS/Dynamic Modulus Test Procedure 62 4.3 Applications 64 4.4 Cost of the ECS/Dynamic Modulus Set-Up 65 Chapter 5 Conclusions and Recommendations 65 5.1 Conclusions 65 5.2 Recommendations 67 References 69 Appendixes
