Measuring Crack Propagation Resistance of Asphalt Mixtures Using Notched Samples in the TSRST

There have been a number of mixture fracture tests developed to understand thermal cracking. With the exception of the Thermal Stress Restrained Specimen Test (TSRST), almost all of the tests simulate the low temperature cracking using mechanical loading, rather than thermal loading. These mechanical loading tests also do not commonly measure the Coefficients of Thermal Contraction (CTC) or the glass transition change, which is measured in the modified TSRST. One of the shortcomings of the current TSRST protocol is the use of monolithic samples with no notches, which cannot be used to derive fracture propagation properties. The findings of this study indicate that un-notched samples require higher energy and lower temperatures to initiate the crack. However, if the crack already exists, propagation can happen at higher temperatures and the energy required for propagation is highly dependent on mixture composition, but only marginally on cooling rate. Hence, the Asphalt Thermal Cracking Analyzer (ATCA) test with notched samples provides a significant advantage as compared to the other cracking tests, because all required properties (including relaxation modulus, cracking propagation resistance, and CTC) can be measured. Finally, it is concluded that both un-notched and notched samples are needed for reliable prediction of pavement cracking.

Language

  • English

Media Info

  • Media Type: Print
  • Pagination: pp. 1-21.
  • Monograph Title: Proceedings of the Sixth-Second Annual Conference of the Canadian Technical Asphalt Association (CTAA): Halifax, Nova Scotia

Subject/Index Terms

Filing Info

  • Accession Number: 01668498
  • Record Type: Publication
  • Source Agency: Transportation Association of Canada (TAC)
  • Files: ITRD, TAC
  • Created Date: May 3 2018 3:17PM