A major distress mode in asphalt pavements is low temperature cracking, which results from the contraction and expansion of the asphalt pavement under extreme temperature changes. The potential for thermal cracking involves interplay between the environment, the road structure, and importantly the properties of the asphalt mixture. In the present study, the low temperature cracking performance of asphalt mixture has been investigated numerically and experimentally. A low temperature cracking model has been utilized, which was developed by integrating fracture energy threshold into an asphalt concrete thermal fracture model considering non-linear thermal contraction coefficients. Based on the asphalt concrete mixture viscoelastic properties, this enhanced model can predict thermally-induced stresses and fracture temperatures. It was observed that the thermal contraction coefficient in asphalt concrete is nonlinear in the temperature range of interest for low temperature cracking. The implications of having nonlinear thermal contraction coefficient were investigated numerically. From the analysis, it was found that this enhanced model can be utilized to evaluate the low temperature cracking performance of asphalt mixtures and rank them accordingly. Interestingly, non-linear thermal contraction coefficient gave much better prediction than the linear approach.
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