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2018 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 877 Performance-Based Mix Design of Porous Friction Courses Donald Watson Nam H. Tran Carolina Rodezno Adam J. Taylor NatioNal CeNter for asphalt teChNology Auburn, AL Tommy M. James, Jr. advaNCed Materials serviCes, llC Auburn, AL Subscriber Categories Design â¢ Materials â¢ Pavements 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 877 Project 01-55 ISSN 2572-3766 (Print) ISSN 2572-3774 (Online) ISBN 978-0-309-39030-9 Library of Congress Control Number 2018943786 Â© 2018 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 CRP STAFF FOR NCHRP RESEARCH REPORT 877 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 Natalie Barnes, Associate Director of Publications Scott E. Hitchcock, Senior Editor NCHRP PROJECT 01-55 PANEL Field of DesignâArea of Pavements Mylinh Lidder, Nevada DOT, Carson City, NV (Chair) Richard S. Gribbin, Jas. W. Glover Ltd., Honolulu, HI Thomas A. Kane, New York State DOT, Albany, NY Tanya M. Nash, PRI Asphalt Technologies, Tampa, FL Shihui Shen, Pennsylvania State UniversityâAltoona, Altoona, PA Eric J. Weaver, FHWA Liaison
This report presents a proposed AASHTO standard mix design method for porous asphalt friction courses. Thus, the report will be of immediate interest to materials engineers in state highway agencies and in the construction industry with responsibility for design of porous friction courses (PFCs). PFCs have been used in the United States for many years. Their open aggregate grada- tions and resultant high air void contents provide PFCs with the ability to quickly remove water from the surface of a roadway, thus reducing the potential for vehicles to hydroplane and improving skid resistance. Splash, spray, and glare are also reduced, improving pave- ment marking visibility in wet weather. PFCs can also provide additional environmental benefits by reducing the pollutant load of storm water runoff as well as traffic noise. Despite their many benefits, the use of PFCs has been limited in part because of cost, lack of a standard mixture design method, premature failure by raveling or stripping, and loss of functionality by clogging with debris. In addition to the need to develop improved maintenance methods to address clogging, the performance of PFC mixtures will benefit from the development of a standardized mixture design method that balances durability in terms of resistance to premature failure with functionality in terms of permeability and noise reduction. The objective of this research was to develop a performance-based mix design procedure for PFC mixtures. The procedure is based on the use of the Superpave gyratory compactor and addresses both selection of materials and the use of laboratory performance tests and criteria for mixture properties related to rutting, raveling, cracking, moisture susceptibility, and permeability. The goal was to achieve the required balance in the mix design between PFC durability and functionality. The research was performed by the National Center for Asphalt Technology in Auburn, Alabama, with the support of Advanced Materials Services, LLC, also of Auburn, Alabama. The research developed a balanced mix design approach for designing PFC mixtures. Performance tests and related criteria for durability, cracking, and cohesiveness were selected. The applicability and suitability of the selected tests and criteria were determined through evaluation of six PFC mixes with known good and poor performance in the field. The research found that the air voids content of PFC mixtures is directly related to their permeability, and the design method proposes a minimum permeability rate of 50 meters/ day and a minimum design air void content of 15%. The Cantabro Test proved a good indicator of mix durability and resistance to raveling, and a maximum loss of 20% is sug- gested. The indirect tensile strength test, based on a modified version of AASHTO T 283, and mixture shear tests were identified as good indicators of mix cohesiveness. The peak F O R E W O R D By Edward T. Harrigan Staff Officer Transportation Research Board
load of the I-FIT semicircular bend test was shown to be a good measure of resistance to cracking. Finally, the use of increased aggregate content passing the #200 sieve provided more durable mixtures for those designs that have high air voids, high Cantabro stone loss, and low tensile strength. The practical outcome of the project is a proposed AASHTO standard mix design method for porous asphalt friction courses. This report fully documents the research and includes two appendices presenting (1) the proposed standard method and (2) detailed information on the mix designs evaluated in the research. (The second appendix, Appendix B: Mix Designs Evaluated in This Study, can be downloaded from the NCHRP Project 01-55 web site at https://apps.trb.org/cmsfeed/ TRBNetProjectDisplay.asp?ProjectID=3627.)
1 Summary 3 Chapter 1 Introduction 3 Background 3 Objective and Scope 5 Chapter 2 Literature Review 5 Introduction 5 Benefits of Porous Mixtures 5 Reduced Hydroplaning and Improved Friction 6 Backsplash, Spray, and Glare Reduction 7 Pavement Noise Reduction 8 Mix Designs 8 Suitable Materials 9 Design Gradation Selection 11 Determining the Optimum Asphalt Binder Content 12 State of the Practice 12 Selection of Materials 18 Optimum Binder Content Selection 21 Construction and Maintenance of PFC Mixes 23 Performance Testing 23 Moisture Susceptibility 23 Cantabro Abrasion Testing 24 Field Performance 25 Factors Affecting Performance of PFC Mixes 25 Raveling 26 Delamination 27 Top-Down Cracking 27 Loss of Permeability over Time 30 Loss of Noise Reduction over Time 31 Issues Related to Cold Weather 32 Lift Thickness 35 Chapter 3 Work Plan 35 Introduction 36 Verification of PFC Mix Designs 36 Part 1âDevelopment of Performance-Based PFC Mix Design 37 Part 2âOptimizing Performance-Based Mix Design Procedure for PFC 37 Experiment 1âEffect of Added Dust 38 Experiment 2âEvaluation of Binder Modification 39 Experiment 3âEffect of Lift Thickness-to-NMAS Ratio C O N T E N T S
40 Chapter 4 Methodology 40 Introduction 40 Volumetric Analysis 41 Cantabro Testing 41 Draindown 42 Wet Track Abrasion Test 42 Hamburg Wheel-Tracking Test 44 Tensile Strength Ratio 44 Shear Strength 45 Permeability 46 Cracking 46 Texas Overlay Test 47 I-FIT 49 Laboratory Conditioning of Specimens 50 Chapter 5 Part 1: Evaluation of Mix Designs 50 Introduction 52 Results and Discussion 52 Cantabro Testing 55 Volumetric Results 60 Performance Testing 64 Cracking Susceptibility Test Results 74 Chapter 6 Part 2 74 Experiment 1: Effect of Increased P-200 Content 74 Introduction 74 Results and Discussion 89 Experiment 2: Effect of Binder Modification 89 Introduction 90 Results and Discussion 93 Hamburg Results by Binder Type 101 Experiment 3: Evaluation of the Effect of Layer Thickness on Performance 101 Introduction 101 Results and Discussion 103 Chapter 7 Performance-Based Mix Design Procedure 103 Key Mix Properties Affecting Field Performance 103 Design Air Voids 104 Film Thickness 104 Voids in Mineral Aggregate 105 Voids in Coarse Aggregate Ratio 106 Permeability Results 107 Draindown 107 Cantabro Stone Loss 107 Moisture Susceptibility and Mixture Cohesiveness 108 Shear Strength 109 Cracking Tests 110 Hamburg Wheel-Tracking Test 110 Proposed Revisions to AASHTO PP 77
112 Effect of Added P-200 Material 112 Design Air Voids, Permeability, and Draindown 113 Durability and Rutting Resistance 114 Cracking Resistance 115 Summary 116 Effect of Fiber 117 Effect of Binder Modification 117 Design Air Voids and Permeability 117 Draindown 118 Durability and Rutting Resistance 120 Effect of Layer Thickness 120 Balanced Mix Design Framework for PFC Mixtures 122 Chapter 8 Conclusions and Recommendations for Future Research 122 Findings 122 Conclusions 123 Recommendations for Future Research 125 References 129 Appendix A Draft Performance-Based Mix Design Procedure for Porous Friction Course 135 Appendix B Mix Designs Evaluated in This Study 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.