U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
202-366-4000


Skip to content
Facebook iconYouTube iconTwitter iconFlickr iconLinkedInInstagram

Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations

 
Report
This report is an archived publication and may contain dated technical, contact, and link information
Back to Publication List        
Publication Number:  FHWA-HRT-99-143    Date:  June 2001
Publication Number: FHWA-HRT-99-143
Date: June 2001

 

Microdamage Healing in Asphalt and Asphalt Concrete, Volume III: A Micromechanics Fracture and Healing Model for Asphalt Concrete

This report is available only in PDF format.

PDF Version (4.91 mb)

PDF files can be viewed with the Acrobat® Reader®

Abstract

Volume 3 documents the development of a micromechanics fracture and healing model for asphalt concrete. This model can be used to calculate the density and growth of microcracks during repeated direct tensile controlled-strain loading. The model is based on a relationship among stiffness changes in the mixture as damage occurs, the rate of change in dissipated pseudo strain energy as loading are applied to the samples and as damage occurs and mixture properties including crack length changes upon loading and mixture cohesive surface energies. The report demonstrates that microcrack growth is the dominate mode of distress at temperatures below 25C and that microcrack healing is the dominate mode of recovery of dissipated pseudo strain energy at these test temperatures. However, at temperatures above about 25C, the predominate mode of distress is plastic damage. Cracking rates during fatigue damage are related to de-wetting cohesive surface energy measurements of the bitumen whereas microcracking healing rates are related to wetting cohesive surface energy measurements of the bitumen. Surface energies of five bitumens with widely different chemical compositions were found to correlate strongly with healing properties as defined by viscoelastic fracture and healing theory.

 

 

Federal Highway Administration | 1200 New Jersey Avenue, SE | Washington, DC 20590 | 202-366-4000
Turner-Fairbank Highway Research Center | 6300 Georgetown Pike | McLean, VA | 22101