Disc Shaped Compact Tension (DCT) Specifications Development for Asphalt Pavement Andrea Schokker, Principal Investigator Department of Civil Engineering University of Minnesota Duluth JUNE 2019 Research Project Final Report 2019-24 RESEARCH SERVICES & LIBRARY • mndot.gov/research To request this document in an alternative format, such as braille or large print, call 651-366-4718 or 1- 800-657-3774 (Greater Minnesota) or email your request to [email protected]. Please request at least one week in advance. Technical Report Documentation Page 1. Report No. 2. 3. Recipients Accession No. MN/RC 2019-24 4. Title and Subtitle 5. Report Date Disc shaped compact tension (DCT) specifications development June 2019 for asphalt pavement 6. 7. Author(s) 8. Performing Organization Report No. Eshan V. Dave, Mirkat Oshone, Andrea Schokker and Chelsea E. Bennett 9. Performing Organization Name and Address 10. Project/Task/Work Unit No. Department of Civil and Environmental Engineering CTS #2015015 University of New Hampshire 11. Contract (C) or Grant (G) No. 33 Academic Way, Durham NH 03824 (C) 99008 (wo) 162 12. Sponsoring Organization Name and Address 13. Type of Report and Period Covered Minnesota Department of Transportation Final Report Office of Research & Innovation 14. Sponsoring Agency Code 395 John Ireland Boulevard, MS 330 St. Paul, Minnesota 55155-1899 15. Supplementary Notes http:// mndot.gov/research/reports/2019/201924.pdf 16. Abstract (Limit: 250 words) The disc-shaped compact tension (DCT) fracture energy test has been shown to discriminate between asphalt mixtures with respect to their thermal cracking potential. This research refines the DCT fracture energy testing procedure, identifies needed adjustments in asphalt mixture to increase fracture energy, determines the suitability of DCT-test-based parameters as indicators of reflective cracking, and proposes threshold values to lower the potential for premature reflective cracking in asphalt overlays. A number of recommendations have been developed to implement outcomes of this research as well as to fill knowledge gaps identified through this study. 17. Document Analysis/Descriptors 18. Availability Statement Fracture tests, Test procedures, Asphalt mixtures, No restrictions. Document available from: Recommendations, Thermal degradation, Cracking, Overlays National Technical Information Services, (Pavements), Improvements, Pavements Alexandria, Virginia 22312 19. Security Class (this report) 20. Security Class (this page) 21. No. of Pages 22. Price Unclassified Unclassified 135 DISC SHAPED COMPACT TENSION (DCT) SPECIFICATIONS DEVELOPMENT FOR ASPHALT PAVEMENT FINAL REPORT Prepared by: Eshan V. Dave and Mirkat Oshone Department of Civil and Environmental Engineering University of New Hampshire Andrea S. Schokker Department of Civil Engineering University of Minnesota Duluth Chelsea E. Bennett Office of Materials and Road Research Minnesota Department of Transportation June 2019 Published by: Minnesota Department of Transportation Office of Research & Innovation 395 John Ireland Boulevard, MS 330 St. Paul, Minnesota 55155-1899 This report represents the results of research conducted by the authors and does not necessarily represent the views or policies of the Minnesota Department of Transportation, the University of Minnesota, or the University of New Hampshire. This report does not contain a standard or specified technique. The authors, the Minnesota Department of Transportation, the University of Minnesota, or the University of New Hampshire do not endorse products or manufacturers. Trade or manufacturers’ names appear herein solely because they are considered essential to this report. ACKNOWLEDGMENTS This research study would not have been possible without the contribution of a number of individuals. We sincerely acknowledge significant efforts from Joe Voels and Shongtao Dai (technical lead for the project) from MnDOT Office of Materials and Road Research for their continuous input during the course of this study as well as for undertaking extensive laboratory testing campaigns. The MnDOT Bituminous Office and specifically John Garrity provided substantial support to this study. All their efforts are sincerely acknowledged. The support and feedback of the project technical advisory panel members (specifically David Van Deusen, Eddie Johnson, Eyoab Zegeye and Luke Johanneck) is very much appreciated. We would also like thank the Minnesota DOT Research Services Section for their help in administration of this project, especially Katie Fleming (administrative liaison for the project). Finally, we would like to thank the staff at University of Minnesota’s Center for Transportation Studies (CTS) for all their help during the course of the project. TABLE OF CONTENTS CHAPTER 1: INTRODUCTION ...............................................................................................................1 CHAPTER 2: DEVELOPMENT OF DATABASE OF FRACTURE ENERGY ON CURRENT ASPHALT MIXTURES ..2 2.1 Introduction ........................................................................................................................................ 2 2.2 Database Details ................................................................................................................................. 2 2.2.1 Project Information ..................................................................................................................... 3 2.2.2 Mix Information .......................................................................................................................... 4 2.2.3 Testing Information ..................................................................................................................... 6 CHAPTER 3: PROJECT SELECTION, SAMPLE PROCUREMENT AND TEMPERATURE CONDITIONING STUDY ..........................................................................................................................................................8 3.1 Introduction ........................................................................................................................................ 8 3.2 Project Information ............................................................................................................................ 8 3.3 Temperature Conditioning Study ..................................................................................................... 13 3.3.1 Phase I ....................................................................................................................................... 13 3.3.2 Phase II ...................................................................................................................................... 14 3.4 Preliminary Inter-Laboratory Comparison ........................................................................................ 15 CHAPTER 4: DCT TESTING AND DATA ANALYSIS ................................................................................ 19 4.1 Introduction ...................................................................................................................................... 19 4.2 Overview of Round Robin Testing Campaign ................................................................................... 19 4.3 Round Robin Testing Results and Discussions .................................................................................. 21 4.4 Aging Study ....................................................................................................................................... 26 4.4.1 Mix Design Specimens ............................................................................................................... 26 4.4.2 Reheat Specimens ..................................................................................................................... 27 4.4.3 Non-Reheat Specimens ............................................................................................................. 28 4.4.4 Field Core Specimens ................................................................................................................ 29 4.4.5 Comparison of Different Aging States ....................................................................................... 30 4.5 Summary ........................................................................................................................................... 32 CHAPTER 5: PILOT DCT SPECIFICATION DEVELOPMENT ..................................................................... 33 5.1 Introduction ...................................................................................................................................... 33 5.2 Statistical Analysis to Recommend Reproducability Limits for DCT Fracture Energy ...................... 33 5.3 Pilot DCT Specification ...................................................................................................................... 34 CHAPTER 6: EFFECT OF MIX DESIGN PARAMETERS ON LOW TEMPERATURE CRACKING PERFORMANCE ........................................................................................................................................................ 36 6.1 Introduction ...................................................................................................................................... 36 6.2 Mix Parameters ................................................................................................................................ 36 6.3 Data Extent ......................................................................................................................................