Relating asphalt binder elastic recovery properties to HMA crack modeling and fatigue life prediction

Fatigue cracking is one of the major distresses occurring in hot-mix asphalt (HMA) pavements, which is a consequence of accumulation of damage under repeated load applications and changes in the environmental conditions. HMA is predominantly composed of aggregates and asphalt binder, where the latter plays a significant role in the HMA fatigue performance. The elastic recovery of asphalt binders is one of the characteristic properties that are hypothesized to play a significant role in the fatigue cracking resistance of HMA pavements. In this study, the relationships between the asphalt binder elastic recovery properties and the HMA fatigue performance were comparatively investigated. Two asphalt binder tests, namely the elastic recovery (ER) and multiple stress creep recovery (MSCR) tests were conducted to comparatively characterize the asphalt binder elastic recovery properties in the laboratory, and their results were then correlated to the predicted HMA fatigue life based on the TxME modeling software, which was subsequently validated with other laboratory test results and field performance data. Eleven typical Texas HMA mixes collected from different construction sites were used for the study. Overall, the results indicated that HMA mixes with high asphalt binder elastic recovery properties (⩾59%) exhibited better cracking resistance potential with long predicted fatigue life (>150 months), which was also consistent with other studies and field performance observations. For mixes with low elastic recovery properties (<59%), there is no clear correlation with the predicted fatigue life.