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2017 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 RESEARCH REPORT 863 Material Properties of Cold In-Place Recycled and Full-Depth Reclamation Asphalt Concrete Charles W. Schwartz University of Maryland College Park, MD and Brian K. Diefenderfer Benjamin F. Bowers virginia transportation research coUncil Charlottesville, VA Subscriber Categories Construction â¢ Maintenance and Preservation â¢ Materials 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 is the most effective way to solve 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 results in increasingly complex problems of wide inter- est to highway authorities. These problems are best studied through a coordinated program of cooperative research. Recognizing this need, the leadership of the American Association of State Highway and Transportation Officials (AASHTO) in 1962 ini- tiated an objective national highway research program using modern scientific techniquesâthe National Cooperative Highway Research Program (NCHRP). NCHRP is supported on a continuing basis by funds from participating member states of AASHTO and receives the full cooperation and support of the Federal Highway Administration, United States Department of Transportation. The Transportation Research Board (TRB) of the National Academies of Sciences, Engineering, and Medicine was requested by AASHTO to administer the research program because of TRBâs recognized objectivity and understanding of modern research practices. TRB is uniquely suited for this purpose for many reasons: TRB maintains an extensive com- mittee structure from which authorities on any highway transportation subject may be drawn; TRB possesses avenues of communications and cooperation with federal, state, and local governmental agencies, univer- sities, and industry; TRBâs relationship to the National Academies is an insurance of objectivity; and TRB maintains a full-time staff of special- ists in highway transportation matters to bring the findings of research directly to those in a position to use them. The program is developed on the basis of research needs identified by chief administrators and other staff of the highway and transportation departments, by committees of AASHTO, and by the Federal Highway Administration. Topics of the highest merit are selected by the AASHTO Special Committee on Research and Innovation (R&I), and each year R&Iâs recommendations are proposed to the AASHTO Board of Direc- tors and the National Academies. Research projects to address these topics are defined by NCHRP, and qualified research agencies are selected from submitted proposals. Administration and surveillance of research contracts are the responsibilities of the National Academies and TRB. The needs for highway research are many, and NCHRP can make significant contributions to solving 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 research 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 by going to http://www.national-academies.org and then searching for TRB Printed in the United States of America NCHRP RESEARCH REPORT 863 Project 09-51 ISSN 2572-3766 (Print) ISSN 2572-3774 (Online) ISBN 978-0-309-44671-6 Library of Congress Control Number 2017960991 Â© 2017 National Academy of Sciences. All rights reserved. COPYRIGHT INFORMATION 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, FRA, FTA, Office of the Assistant Secretary for Research and Technology, PHMSA, or TDC 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 research report was reviewed by the technical panel and accepted for publication according to procedures established and overseen by the Transportation Research Board and approved by the National Academies of Sciences, Engineering, and Medicine. The opinions and conclusions expressed or implied in this report are those of the researchers who performed the research and are not necessarily those of the Transportation Research Board; the National Academies of Sciences, Engineering, and Medicine; or the program sponsors. The Transportation Research Board; the National Academies of Sciences, Engineering, and Medicine; and the sponsors of 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 the report.
The National Academy of Sciences was established in 1863 by an Act of Congress, signed by President Lincoln, as a private, non- governmental institution to advise the nation on issues related to science and technology. Members are elected by their peers for outstanding contributions to research. Dr. Marcia McNutt is president. The National Academy of Engineering was established in 1964 under the charter of the National Academy of Sciences to bring the practices of engineering to advising the nation. Members are elected by their peers for extraordinary contributions to engineering. Dr. C. D. Mote, Jr., is president. The National Academy of Medicine (formerly the Institute of Medicine) was established in 1970 under the charter of the National Academy of Sciences to advise the nation on medical and health issues. Members are elected by their peers for distinguished contributions to medicine and health. Dr. Victor J. Dzau is president. The three Academies work together as the National Academies of Sciences, Engineering, and Medicine to provide independent, objective analysis and advice to the nation and conduct other activities to solve complex problems and inform public policy decisions. The National Academies also encourage education and research, recognize outstanding contributions to knowledge, and increase public understanding in matters of science, engineering, and medicine. Learn more about the National Academies of Sciences, Engineering, and Medicine at www.national-academies.org. The Transportation Research Board is one of seven major programs of the National Academies of Sciences, Engineering, and Medicine. The mission of the Transportation Research Board is to increase the benefits that transportation contributes to society by providing leadership in transportation innovation and progress through research and information exchange, conducted within a setting that is objective, interdisciplinary, and multimodal. The Boardâs varied committees, task forces, and panels annually engage about 7,000 engineers, scientists, and other transportation researchers and practitioners from the public and private sectors and academia, all of whom contribute their expertise in the public interest. The program is supported by state transportation departments, federal agencies including the component administrations of the U.S. Department of Transportation, and other organizations and individuals interested in the development of transportation. Learn more about the Transportation Research Board at www.TRB.org.
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 AUTHOR ACKNOWLEDGMENTS The research reported herein was performed under NCHRP Project 09-51 by the Department of Civil and Environmental Engineering at the University of MarylandâCollege Park, MD (UMD), with the Virginia Transportation Research Council (VTRC), Wirtgen GmbH, and Colas Solutions Inc. The report was authored by Dr. Charles W. Schwartz, UMD (Principal Investigator), Dr. Brian K. Diefenderfer, Associate Principal Research Scientist, VTRC (Co-Principal Investigator), and Dr. Benjamin F. Bowers, Research Scientist, VTRC. Mr. Mike Marshall (Wirtgen GmbH) and Mr. Todd Thomas (Colas Solutions Inc.) also contributed to the work described in this report. The work was done under the general supervision of Dr. Schwartz at UMD. The authors greatly appreciate the efforts of those who assisted with collecting field cores for this study. They include personnel from the following state departments of transportation: Colorado; Delaware; Illinois; Kansas; Maine; New York State; Utah; and Washington State; along with the West Virginia Division of Highways; Los Angeles County Department of Public Works; City of San Jose Department of Public Works; City of Edmonton Transportation Services; FHWA Eastern and Central Federal Lands Highway Divisions; Ministry of Transportation of Ontario; Blount Construction, S&ME, and Road Science Georgia (Georgia); S. Drain Engineering of Illinois; AMEC Environment and Infrastructure (Ontario); and Pavement Recycling Systems (California). CRP STAFF FOR NCHRP RESEARCH REPORT 863 Christopher J. Hedges, Director, Cooperative Research Programs Lori L. Sundstrom, Deputy Director, Cooperative Research Programs Edward T. Harrigan, Senior Program Officer Anthony P. Avery, Senior Program Assistant Eileen P. Delaney, Director of Publications Sharon Lamberton, Editor NCHRP PROJECT 09-51 PANEL Field of Materials and ConstructionâArea of Bituminous Materials Andrew Gisi, Topeka, KS (Chair) Julie E. Kliewer, Arizona DOT, Phoenix, AZ Gaylon L. Baumgardner, Paragon Technical Services, Inc., Jackson, MS Thomas A. Kane, New York State DOT, Albany, NY Leslie A. McCarthy, Villanova University, Villanova, PA Mohammed A. Mulla, North Carolina DOT, Raleigh, NC John A. Siekmeier, Minnesota DOT, Maplewood, MN Jeffrey S. Uhlmeyer, Washington State DOT, Turnwater, WA Michael Voth, FHWA Liaison
This report presents procedures for determining material properties of cold-recycled asphalt mixtures for input to structural design and analysis programs and suggested Level 3 modulus values for these materials for use in pavement structural analyses with Pavement ME Design. The report will be of immediate interest to engineers in state highway agencies and industry with responsibility for structural design and analysis of pavements incorporating cold-recycled, asphalt-stabilized materials. Highway agencies are placing increasing emphasis on sustainability, recycling, and mak- ing maximum use of existing pavement assets in rehabilitation strategies. Such emphasis has led agencies to explore the advantages of producing asphalt mixtures using cold-recycling technology, particularly cold in-place recycling (CIR), cold central-plant recycling (CCPR), and full-depth reclamation (FDR). Recent improvements in asphalt emulsion chemistry that enable better aggregate coating, shorter curing times, and the elimination of solvents have substantially increased the appli- cability of mixtures produced by CIR, CCPR, and FDR. Unfortunately, minimal information is available on the material properties of these asphalt mixtures to facilitate the structural design of pavements incorporating stabilized base materials produced with these processes. In particular, the Mechanistic-Empirical Pavement Design Guide (MEPDG) developed under NCHRP Project 1-37A and now available as AASHTOWare Pavement ME Design provides only minimal guidance for using these processes and materials. The objective of this research was to determine relevant properties of CIR, CCPR, and FDR materials with emulsified or foamed asphalt recycling/stabilizing agents for input into pavement structural design programs. The research was conducted by the University of Maryland, College Park, Maryland, with support from the Virginia Transportation Research Council, Charlottesville, Virginia. The project developed a small-scale testing procedure that permits the measurement of the dynamic modulus and repeated load permanent deformation characteristics of field-produced and cured asphalt-stabilized, cold-recycled mixtures. These properties were determined for cold-recycled materials sampled from field projects across the United States. Suggested Level 3 modulus inputs were developed by the research team for use in structural design and analysis programs. Finally, structural analyses were conducted with these inputs in Pavement ME Design that demonstrated the sensitivity of the test data to the different stabilizing agents used in the various field projects. This report fully documents the research and includes one Appendix: Deviations from AASHTO TP 79-15. F O R E W O R D By Edward Harrigan Staff Officer Transportation Research Board
Note: Photographs, figures, and tables in this report may have been converted from color to grayscale for printing. The electronic version of the report (posted on the web at www.trb.org) retains the color versions. 1 Summary 5 Chapter 1 Introduction 5 1.1 Background 6 1.2 Study Objectives 8 Chapter 2 Projects and Materials Investigated 8 2.1 Description of Projects 8 2.2 Description of Cores 13 Chapter 3 Specimen Preparation and Testing Methods 13 3.1 Test Specimen Fabrication 16 3.2 Small-scale Test Specimen Geometry 18 3.3 Dynamic Modulus Testing 19 3.4 RLPD Testing 21 Chapter 4 Dynamic Modulus Test Results 21 4.1 Outlier Analysis 22 4.2 Significance Testing of Dynamic Modulus Data at 10 Hz 25 4.3 Master Curve Analysis 30 4.4 Analysis of Fitting Parameters 32 4.5 Analysis of Phase Angle 37 4.6 Relationship between Stiffness and Mixture Properties 42 Chapter 5 RLPD Test Results 42 5.1 RLPD Analysis 42 5.2 Outlier Analysis 45 5.3 RLPD Data Envelopes 48 5.4 Relationship between Rutting Susceptibility and Density 50 Chapter 6 Performance Evaluation 50 6.1 The Mechanistic-Empirical Pavement Design Guide 51 6.2 Initial Comparisons 63 6.3 Rutting Performance Evaluation of All Cold-recycled Materials 69 Chapter 7 Conclusions 72 References 74 Appendix C O N T E N T S