Fracture Tolerance of Asphalt Binder at Intermediate Temperatures

Load-induced fatigue cracking is one of the primary distress modes in asphalt pavements at intermediate temperatures. The asphalt community is still searching for a reliable methodology to obtain relevant properties of asphalt binder to assess relative cracking performance. This study proposed an enhanced binder fracture energy (BFE) test to determine the fracture tolerance of asphalt binders. The BFE test successfully differentiated unmodified and modified binders based on the characteristics of the true stress–true strain curve. More importantly, binder fracture energy density (FED) quantitatively distinguished rubber-modified, hybrid, and polymer-modified binders. Finally, fracture properties translated well from binder to mixture such that binders with higher FED resulted in higher mixture FED values. Mixture cracking performance was evaluated by using the energy ratio (ER) parameter that is governed by both failure limit (FED) and rate of damage of asphalt mixtures. An excellent correlation was found between binder FED and mixture ER, given binders containing SBS polymer typically lead to a low mixture rate of damage. Therefore, it appears that binder FED obtained from the BFE test can be used to assess relative cracking performance. Future research on binder rate of damage may be necessary to account for new binder modifications.

Language

  • English

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Filing Info

  • Accession Number: 01632901
  • Record Type: Publication
  • Files: TRIS, ASCE
  • Created Date: Apr 21 2017 3:03PM