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Federal Highway Administration Research and Technology
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Publication Number:  FHWA-HRT-98-141    Date:  June 2001
Publication Number: FHWA-HRT-98-141
Date: June 2001


Microdamage Healing in Asphalt and Asphalt Concrete, Volume I: Microdamage and Microdamage Healing, Project Summary Report

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Public Law 102-240, the Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991, directed the Federal Highway Administration in Section 6016 to enter into a 5-year contract research program with the Western Research Institute (WRI) of the University of Wyoming. The title of this research program is Fundamental Properties of Asphalts and Modified Asphalts, Contract No. DTFH6 1 -92-C-00 170. As part of this contract, Task K-Microdamage Healing in Asphalt and Asphalt Concrete was performed by the Texas Transportation Institute of Texas A&M University and North Carolina State University.

This report details the results of the Task K subcontract; the main body of the WRI report will be published subsequently. The results of Task K have advanced our understanding, both theoretically and in terms of measurement, of fatigue damage, especially fatigue cracking, in asphalt pavements. It explicitly and quantitatively considers the impact of healing, the regaining of pavement strength and integrity upon standing without traffic (resting), on fatigue life. This research is expected to forrn the basis of specification testing for fatigue susceptibility and the improvement of fatigue life of asphalt pavements.

T. Paul Teng, P.E. Director

Office of Infrastructure R & D



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