Federal Title PageAuthor's Title PageDisclaimerAcknowledgmentsTable of ContentsList of FiguresList of TablesChapter 1. IntroductionBackgroundObjectivesReport OrganizationChapter 2. Development of Upgraded Overlay TesterIntroductionUpgraded Overlay TesterData InterpretationVariability of Upgraded Overlay TestingSensitivity of Upgraded Overlay TestingOverlay Testing ProtocolSummary and ConclusionsChapter 3. Validation of Upgraded Overlay TesterIntroductionValidation of Upgraded Overlay Tester Using Field Cores with Known Reflective Cracking PerformancePreliminary Pass/Fail Criteria on Reflective Cracking Resistance of Asphalt MixturesComparison Between Overlay Tester and Beam Fatigue TestValidation of Overlay Tester Using MnRoad CoresSummary and ConclusionsChapter 4. Application of the Overlay Tester to Evaluate Reflective Cracking Resistance of Typical TxDOT MixturesInfluence of Asphalt Binder Type on Reflective Cracking ResistanceInfluence of Aggregate Properties on Reflective Cracking ResistanceEvaluation of Reflective Cracking Resistance of TxDOT’s MixtureChapter 5. Case Studies: Optimization of Asphalt Overlay Mixture Design Using the Overlay Tester and Hamburg Wheel Tracking Test (HWTT)IntroductionA Preliminary Framework for Asphalt Overlay Mixture Design, Considering Both Reflective Cracking and RuttingCase Study 1: US82, Wichita Falls, TexasCase Study 2: CMHB-F Design for the Atlanta District, TexasChapter 6. Framework of Overlay Tester Based Reflective Cracking Analysis SystemIntroductionReflective Cracking Modeling Approach Based on Fracture MechanicsFramework of Reflective Cracking Analysis SystemChapter 7. TxDOT’s Brand New Overlay Tester and User ManualOverlay Tester SpecificationsUser Manual for New Overlay TesterChapter 8. Conclusions and RecommendationsConclusionsRecommendationsReferencesTechnical Report Documentation Page 1. Report No. FHWA/TX-05/0-4467-2 2. Government Accession No. 3. Recipient's Catalog No. 4. Title and Subtitle OVERLAY TESTER: A RAPID PERFORMANCE RELATED RACK RESISTANCE TEST C 5. Report Date October 2004 Resubmitted: March 2005 6. Performing Organization Code 7. Author(s) Fujie Zhou and Tom Scullion 8. Performing Organization Report No. Report 0-4467-2 10. Work Unit No. (TRAIS) 9. Performing Organization Name and Address Texas Transportation Institute The Texas A&M University System C ollege Station, Texas 77843-3135 11. Contract or Grant No. Project 0-4467 13. Type of Report and Period Covered Technical Report: eptember 2002-August 2004 S 12. Sponsoring Agency Name and Address Texas Department of Transportation Research and Technology Implementation Office P. O. Box 5080 A ustin, Texas 78763-5080 14. Sponsoring Agency Code 15. Supplementary Notes Project performed in cooperation with the Texas Department of Transportation and the Federal Highway Administration. Project Title: Developing an Upgraded Overlay Tester System to Characterize the Reflection Cracking esistance of Asphalt Concrete R 16. Abstract The focus of many asphalt mixture design procedures over the past 10 years has led to the development of stiffer, drier mixtures. However, these mixes are more difficult to construct and are potentially more prone to reflective cracking. In this research the upgraded overlay tester is introduced and proposed as a simple performance test on reflective cracking. The overlay tester can be run on standard size samples, typically 6 in (150 mm) long by 3 in (75 mm) wide by 1.5 in (38 mm) high. These specimens can be prepared from either field cores or from Superpave Gyratory Compactor (SGC) molded specimens. The test is rapid and repeatable, and poor samples fail in minutes. It characterizes both crack initiation and crack propagation properties of asphalt mixtures. Based on repeatability study results, three replicates are recommended for the overlay tester. Sensitivity studies indicate that the overlay tester provides reasonable test results. Increasing asphalt content will significantly improve the reflective cracking resistance of asphalt mixtures. In a series of tests on Texas mixtures, it was determined that aggregate absorption has a major impact on the performance of specimens in the overlay tester. This topic has not received much attention recently but it obviously needs to be investigated. In the lab these highly absorptive aggregates did not severely impact the rutting performance but they had a major impact on cracking life. The effectiveness of the overlay tester was validated by five case studies in Texas. The overlay tester results all correlated well with the field performance. Furthermore, the overlay tester results have good correlations with beam fatigue test results and low temperature performance of asphalt mixtures in the field. A preliminary framework of asphalt overlay mixture designs and associated criteria have been proposed. Based on the framework, two examples of asphalt overlay mixture designs are presented in this report. This framework and the associated criteria are preliminary and they will need further refinement. Finally, a brand new overlay tester has been manufactured and delivered to TxDOT’s central lab at the edar Park office. In addition, training for the operation and analysis has been provided. C 17. Key Words Reflective Cracking, Overlay Tester, Asphalt Mixtures 18. Distribution Statement No restrictions. This document is available to the public through NTIS: National Technical Information Service 5285 Port Royal Road Springfield, Virginia 22161 http://www.ntis.gov 19. Security Classif.(of this report) Unclassified 20. Security Classif.(of this page) Unclassified 21. No. of Pages 86 22. Price Form DOT F 1700.7 (8-72) Reproduction of completed page authorizedOVERLAY TESTER: A RAPID PERFORMANCE RELATED CRACK RESISTANCE TEST by Fujie Zhou Assistant Research Scientist Texas Transportation Institute and Tom Scullion, P.E. Research Engineer Texas Transportation Institute Report 0-4467-2 Project 0-4467 Project Title: Developing an Upgraded Overlay Tester System to Characterize the Reflection Cracking Resistance of Asphalt Concrete Performed in cooperation with the Texas Department of Transportation and the Federal Highway Administration October 2004 Resubmitted: March 2005 TEXAS TRANSPORTATION INSTITUTE The Texas A&M University System College Station, Texas