Phase-Transition Temperature of Asphalt Materials Based on DMA

Asphalt materials including binder, mortar, and mixture are extensively used in the field of pavement engineering considering their obvious viscoelastic properties. To study the phase-transition temperature (T_p) of asphalt materials, we apply dynamic mechanical analysis (DMA) to conduct several temperature-sweep mode tests and compare the T_p values among these materials with similar sizes. Meanwhile, 27 AC5 mixtures are tested to determine the impact of binder type, gradation and, binder content on T_p. Results indicate that the T_p of binder and mortar is negative, but that of mixture is positive. Good correlations among T_p of binder, mortar, and mixture with the same binder type are observed, showing that binder quality is the key factor affecting T_p. Gradation type also affects T_p, and the mixture with a finer gradation has a lower T_p. Among the AC5 asphalt mixtures, the T_p of AR mixture is lower than those of the others, thereby demonstrating better low-temperature performance.