Mixture Versus Neat-Film Binder Oxidation and Hardening and the Impact of Binder Oxidation on Estimated Mixture Fatigue Life

Asphalt oxidation causes major changes to binder properties and is hypothesized to be a major contributor to age-related pavement failure such as fatigue cracking. Neat film asphalt oxidative aging stiffens the binder, leading to higher binder stresses under a given deformation; when these stresses exceed the strength of the binder, failure occurs. Thus, heavily-aged binders exhibit a significantly reduced failure strain (e.g. in direct tension) compared to less aged binders. However, the impact of binder oxidation in HMAC mixtures on fatigue lives has not been adequately addressed. In this study, we have investigated the effect of binder oxidation on hot mix asphalt concrete (HMAC) mixture fatigue performance under strain-controlled conditions in the laboratory. Binder aging was characterized by FT-IR carbonyl area growth and by changes in DSR function hardening (G'/(eta'/G')). HMAC Mixture fatigue life was estimated by a calibrated mechanistic with surface energies (CMSE) fatigue approach. Binders recovered from aged mixtures track across the DSR function map (log G' versus eta'/G'), following the same path as neat binder aged in a 60 C environmental room, a path that previous study has shown correlates well with significant decreases in binder ductility. Mixture fatigue resistance measured under strain-controlled conditions in the laboratory also decreases dramatically in direct relation to binder oxidative hardening.

Language

  • English

Media Info

  • Media Type: CD-ROM
  • Features: Figures; References; Tables;
  • Pagination: 18p
  • Monograph Title: TRB 86th Annual Meeting Compendium of Papers CD-ROM

Subject/Index Terms

Filing Info

  • Accession Number: 01044196
  • Record Type: Publication
  • Report/Paper Numbers: 07-2390
  • Files: TRIS, TRB
  • Created Date: Feb 8 2007 7:04PM