Identification of a Suitable Rheology Model and Shear Failure Mechanism of Asphalt Mixtures

Instability rutting, which is shear related and occurs when the compacted mixture cannot resist critical stress conditions occurred at the pavement surface, is a major distress mode in flexible pavements. According to a NCHRP Report 465, the point at which excessive deformations occur from laboratory rut testing is the most important factor that determines the rutting performance of asphalt mixtures. Nevertheless, a clear and complete failure mechanism has not been identified. This research focuses on identifying a suitable rheology model and a failure criterion for asphalt mixtures that are loaded under repeated shearing forces at high temperature. To this purpose, Rotary Asphalt Wheel Tester (RAWT), which has been recently developed to conduct rutting performance evaluation of asphalt mixtures, was used as a main test in this study. From the results of laboratory rut testing, it was found that a linear viscoelastic approach appears valid and suitable for characterizing the rutting behavior of asphalt mixtures, and an energy-based failure mechanism appears to be a valid shear failure criterion. From this observation, the parameter “shear failure time” developed in this study, appears to have potential for evaluating a mixture’s rutting performance.

Language

  • English

Media Info

  • Media Type: CD-ROM
  • Features: Figures; Photos; References;
  • Pagination: 25p
  • Monograph Title: TRB 86th Annual Meeting Compendium of Papers CD-ROM

Subject/Index Terms

Filing Info

  • Accession Number: 01044578
  • Record Type: Publication
  • Report/Paper Numbers: 07-0339
  • Files: TRIS, TRB
  • Created Date: Feb 8 2007 4:54PM