EVALUATION OF SHRP INDIRECT TENSION TESTER TO MITIGATE CRACKING IN ASPHALT CONCRETE PAVEMENTS AND OVERLAYS

Specific objectives of this project were as follows: (1) Evaluate the measurement system for the existing Strategic Highway Research Program (SHRP) Indirect Tension Tester (IDT) to identify improvements that need to be made to make the test more practical and reliable; (2) Develop an improved measurement system based on the findings of this evaluation; (3) Evaluate existing data acquisition and data reduction software for the SHRP IDT to identify limitations and deficiencies associated with the determination of relevant asphalt mixture properties; (4) Develop and evaluate data acquisition and data reduction software as necessary to determine relevant asphalt mixture properties from the SHRP IDT; (5) Determine the minimum amount of mixture testing required to reliably determine the master creep compliance curve of asphalt mixtures by evaluating the use of empirical and theoretical relationships between properties of asphalt binders and asphalt mixtures, including the binder-to-mixture stiffness relationship developed for use in the Superpave mixture design and analysis system; (6) Develop and evaluate a method and data reduction software to generate the master creep compliance curve automatically from creep compliance test results at multiple test temperatures; (7) Use the SHRP IDT and the measurement and data analysis procedures developed to determine the properties of several typical asphalt mixtures used in Florida and use the data to illustrate how the data can be used to evaluate the performance of asphaltic mixtures; and (8) Establish recommendations for further development and implementation of the SHRP IDT to establish an implementable testing system that can be used to establish an asphalt mixture specification based on asphalt mixture properties and/or parameters that control the cracking mechanisms of asphalt pavements and overlays. The results of this study are presented in the following chapters: (1) Introduction; (2) Evaluation of Existing SHRP IDT; (3) Evaluation of Binder-to-Mixture Stiffness Relationships; (4) Improvements to the SHRP IDT Testing and Analysis System; (5) Resilient Modulus from SHRP IDT; (6) Modulus and Failure Limits from SHRP IDT Strength Test; (7) Creep Compliance Curve and m-Value from SHRP IDT; (8) Asphalt Mixture Performance Evaluation Using the SHRP IDT; (9) Future Development and Implementation of the SHRP IDT; and (10) Closure (Summary).