TRANSPORTATION RESEARCH BOARD 2025 EXECUTIVE COMMITTEE*

OFFICERS

CHAIR: Leslie S. Richards, Professor of Practice, University of Pennsylvania, Philadelphia

VICE CHAIR: Joel M. Jundt, Secretary of Transportation, South Dakota Department of Transportation, Pierre

EXECUTIVE DIRECTOR: Victoria Sheehan, Transportation Research Board, Washington, DC

MEMBERS

James F. Albaugh, President and CEO, The Boeing Company (retired), Scottsdale, AZ

Carlos M. Braceras, Executive Director, Utah Department of Transportation, Salt Lake City

Douglas C. Ceva, Vice President, Customer Lead Solutions, Prologis, Inc., Jupiter, FL

Nancy Daubenberger, Commissioner of Transportation, Minnesota Department of Transportation, St. Paul

Marie Therese Dominguez, Commissioner, New York State Department of Transportation, Albany

Garrett Eucalitto, Commissioner, Connecticut Department of Transportation, Newington

Andrew Fremier, Executive Director, Metropolitan Transportation Commission, San Francisco, CA

Martha Grabowski, Professor Emerita, Information Systems, Le Moyne College, Madden College of Business & Economics, Cazenovia, NY

Randell Iwasaki, President and CEO, Iwasaki Consulting Services, Walnut Creek, CA

Carol A. Lewis, Professor, Transportation Studies, Texas Southern University, Houston

Hani S. Mahmassani, W.A. Patterson Distinguished Chair in Transportation; Director, Transportation Center, Northwestern University, Evanston, IL

Scott C. Marler, Director, Iowa Department of Transportation, Ames

Ricardo Martinez, Adjunct Professor of Emergency Medicine, Emory University School of Medicine, Decatur, GA

Russell McMurry, Commissioner, Georgia Department of Transportation, Atlanta

Craig E. Philip, Research Professor and Director, VECTOR, Department of Civil and Environmental Engineering, Vanderbilt University, Nashville, TN

Steward T.A. Pickett, Distinguished Senior Scientist, Cary Institute of Ecosystem Studies, Millbrook, NY

Susan A. Shaheen, Professor and Co-Director, Transportation Sustainability Research Center, University of California, Berkeley

Marc Williams, Executive Director, Texas Department of Transportation, Austin

EX OFFICIO MEMBERS

Michael R. Berube, Deputy Assistant Secretary for Sustainable Transportation, U.S. Department of Energy, Washington, DC

Steven G. Bradbury, Deputy Secretary, U.S. Department of Transportation, Washington, DC

Steven Cliff, Executive Officer, California Air Resources Board, Sacramento

LeRoy Gishi, Chief, Division of Transportation, Bureau of Indian Affairs, U.S. Department of the Interior, Germantown, MD

Firas Ibrahim, Director, Office of Research, Development, and Technology, Office of the Assistant Secretary for Research and Technology (OST-R), Washington, DC

Jason Kelly, Deputy Commanding General for Civil Works and Emergency Operations, U.S. Army Corps of Engineers, Washington, DC

Sandra Knight, President, WaterWonks, LLC, Washington, DC

Ben Kochman, Acting Administrator, Pipeline and Hazardous Materials Safety Administration, Washington, DC

Zahra “Niloo” Parvinashtiani, Engineer, Mobility Consultant Solutions, Iteris Inc., Fairfax, VA, and Chair, TRB Young Members Coordinating Council

Chris Rocheleau, Acting Administrator, Federal Aviation Administration, Washington, DC

Gloria Shepherd, Acting Deputy Administrator, Federal Highway Administration, Washington, DC

Karl Simon, Director, Transportation and Climate Division, U.S. Environmental Protection Agency, Washington, DC

Paul P. Skoutelas, President and CEO, American Public Transportation Association, Washington, DC

Jim Tymon, Executive Director, American Association of State Highway and Transportation Officials, Washington, DC

___________________

^* Membership as of May 2025.

NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM

Evaluation of Post-Consumer
Recycled Plastics in Asphalt Mixtures
via the Dry Process

Randy West
Fan Yin
Maede Mottaghi
Chen Chen
Raquel Moraes
Nam Tran
NATIONAL CENTER FOR ASPHALT TECHNOLOGY AT AUBURN UNIVERSITY
Auburn, AL

Yogesh Kumbargeri
Jean-Pascal Planche
Jeramie Adams
Joseph Rovani
WESTERN RESEARCH INSTITUTE
Laramie, WY

C.J. DuBois
DOW INC.
Lake Jackson, TX

Gayle King
GHK INC.
Galveston, TX

Subscriber Categories
Highways • Materials • 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, and implementable research is the most effective way to solve many problems facing state department of transportation (DOT) administrators and engineers. Often, highway problems are of local or regional interest and can best be studied by state DOTs individually or in cooperation with their state universities and others. However, the accelerating growth of highway transportation results in increasingly complex problems of wide interest 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 initiated an objective national highway research program using modern scientific techniques—the 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 (FHWA), 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 TRB’s recognized objectivity and understanding of modern research practices. TRB is uniquely suited for this purpose for many reasons: TRB maintains an extensive committee 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, universities, and industry; TRB’s relationship to the National Academies is an insurance of objectivity; and TRB maintains a full-time staff of specialists 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 FHWA. Topics of the highest merit are selected by the AASHTO Special Committee on Research and Innovation (R&I), and each year R&I’s recommendations are proposed to the AASHTO Board of Directors, the FHWA, 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 oversight of research contracts are the responsibilities of NCHRP.

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.

NCHRP RESEARCH REPORT 1143

Project 09-66
ISSN 2572-3766 (Print)
ISSN 2572-3774 (Online)
ISBN 978-0-309-73331-1
Library of Congress Control Number 2025936916

© 2025 by the National Academy of Sciences. National Academies of Sciences, Engineering, and Medicine and the graphical logo are trademarks of the 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, APTA, FAA, FHWA, FTA, GHSA, or NHTSA 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.

This material is based upon work supported by the FHWA under Agreement No. 693JJ32350025. The opinions, findings, and conclusions or recommendations expressed or implied in this publication 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; the FHWA; or the program sponsors.

The Transportation Research Board does not develop, issue, or publish standards or specifications. The Transportation Research Board manages applied research projects which provide the scientific foundation that may be used by Transportation Research Board sponsors, industry associations, or other organizations as the basis for revised practices, procedures, or specifications.

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 manufacturers’ names or logos appear herein solely because they are considered essential to the object of the report.

Published research reports of the

NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM

are available from

National Academies Press
500 Fifth Street, NW, Keck 360
Washington, DC 20001

(800) 624-6242

and can be ordered through the Internet by going to

https://nap.nationalacademies.org

Printed in the United States of America

The National Academy of Sciences was established in 1863 by an Act of Congress, signed by President Lincoln, as a private, nongovernmental 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. John L. Anderson 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.nationalacademies.org.

The Transportation Research Board is one of seven major program divisions of the National Academies of Sciences, Engineering, and Medicine. The mission of the Transportation Research Board is to mobilize expertise, experience, and knowledge to anticipate and solve complex transportation-related challenges. The Board’s varied activities annually engage about 8,500 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 departments of transportation, 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.

COOPERATIVE RESEARCH PROGRAMS

CRP STAFF FOR NCHRP RESEARCH REPORT 1143

Monique R. Evans, Director, Cooperative Research Programs

Waseem Dekelbab, Deputy Director, Cooperative Research Programs, and Manager, National Cooperative Highway Research Program

Roberto Barcena, Senior Program Officer

Anthony P. Avery, Senior Program Assistant

Natalie Barnes, Director of Publications

Heather DiAngelis, Associate Director of Publications

Lisa Whittington, Editor

NCHRP PROJECT 09-66 PANEL
Field of Materials and Construction—Area of Bituminous Materials

Samuel B. Cooper, III, Louisiana Department of Transportation and Development, Baton Rouge, LA (Chair)

John A. D’Angelo, D’Angelo Consulting, LLC, Annandale, VA

Daba Gedafa, University of North Dakota, Grand Forks, ND

Robert Q. Kluttz, Kraton Polymers, Houston, TX

Ross “Oak” A. Metcalfe, Montana Department of Transportation, Helena, MT

Kelly Senger, Illinois Department of Transportation, Springfield, IL

Ronald Sines, CRH Americas Materials, Rindge, NH

Jack S. Youtcheff, Jr., FHWA Liaison

Casey Soneira, AASHTO Liaison

FOREWORD

By Roberto Barcena
Staff Officer
Transportation Research Board

NCHRP Research Report 1143: Evaluation of Post-Consumer Recycled Plastics in Asphalt Mixtures via the Dry Process presents performance results and impacts of using post-consumer recycled (PCR) plastics in asphalt mixtures. The evaluations were conducted through a comprehensive laboratory testing plan, consisting of five experiments. The analyses also include comparisons between plant-produced mixes and field samples. This research report will be of immediate interest to pavement design and materials personnel at state and local transportation agencies and asphalt mixture producers. The report can inform their decisions related to the use, handling, testing, and evaluation of asphalt mixtures with PCR plastics.

In late 2016, media reports began generating interest in the possibility of using recycled plastic waste in asphalt mixtures. This idea was marketed as an opportunity to simultaneously improve the quality of asphalt pavements and help address the issue of waste plastics in cities, towns, and waterways across the United States. Thus, a comprehensive research effort was needed to understand how recycled plastics affect the volumetric properties, workability, and surface characteristics of asphalt mixtures and the long-term effects of recycled plastics on various aspects of asphalt pavements, including life-cycle costs, worker safety, environmental impact, and recyclability.

Under NCHRP Project 09-66, “Performance Properties of Laboratory Produced Recycled Plastic Modified (RPM) Asphalt Binders and Mixtures,” Auburn University’s National Center for Asphalt Technology was asked to evaluate the impact of PCR plastic waste—including low-density polyethylene (LDPE), high-density polyethylene (HDPE), and polypropylene (PP)—on the performance properties of asphalt mixtures when added using the dry process.

In addition to the report, the research project produced several deliverables that are available on the National Academies Press webpage for NCHRP Research Report 1143: Evaluation of Post-Consumer Recycled Plastics in Asphalt Mixtures via the Dry Process (https://doi.org/10.17226/28867) under “Resources.” These deliverables are as follows:

• Appendix A: Annotated Bibliography.
• Appendix B: Recycled Plastics in Asphalt Mixtures: Contractor Questionnaire.
• Recycled Plastics Guide.
• Mixture Results Database.
• Workshop Materials.

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CONTENTS

Summary

Chapter 1 Introduction

1.1 Background

1.2 Research Objectives

1.3 Research Approach

Chapter 2 Literature Review

2.1 Availability and Sourcing of Recycled Plastics

2.2 Methods of Incorporating Recycled Plastics

2.3 Laboratory Binder Characterization

2.4 Laboratory Mixture Characterization

2.5 Plant Operations

2.6 Construction

2.7 Health and Safety

2.8 Environmental Impact

2.9 Field Projects

2.10 Other Potential Civil Engineering Applications

Chapter 3 Laboratory Work Plan

3.1 Experiment 1: Characterization and Selection of PCR Plastics

3.2 Experiment 2: Laboratory Characterization of Plant-Produced RPM versus Control Asphalt Mixtures and Extracted Binders

3.3 Experiment 3: Survey on Recycled Plastics in Asphalt Mixtures and Exploratory QC Testing of PCR Plastics

3.4 Experiment 4: Selection of Laboratory Method for Adding Recycled Plastics via the Dry Process

3.5 Experiment 5: Laboratory Characterization of Laboratory-Prepared RPM versus Control Asphalt Mixtures and Extracted Binders

Chapter 4 Results and Findings

4.1 Experiment 1: Characterization and Selection of PCR Plastics

4.2 Experiment 2: Laboratory Characterization of Plant-Produced RPM versus Control Asphalt Mixtures and Extracted Binders

4.3 Experiment 3: Survey on Recycled Plastics in Asphalt Mixtures and Exploratory QC Testing of PCR Plastics

4.4 Experiment 4: Selection of Laboratory Method for Adding Recycled Plastics via the Dry Process

4.5 Experiment 5: Laboratory Characterization of Laboratory-Prepared RPM versus Control Asphalt Mixtures and Extracted Binders

Chapter 5 Conclusions and Future Research

5.1 Conclusions

5.2 Future Research

References

Abbreviations

Appendices