Study on the change rule of low-temperature properties of asphalt binder with aging time

Low-temperature cracking is common distress in asphalt pavements. Understanding the change rule of its low-temperature properties is helpful in investigating the optimal maintenance timing of asphalt pavement. In this paper, the change rule of low-temperature properties of asphalt binders with aging time is investigated by various indexes. Four asphalt binders and four anti-aging modified asphalt binders were subjected to the rolling thin film oven (RTFO) test and pressure aging vessel (PAV) test. Dynamic Shear Rheometer (DSR) with the 4 mm parallel plates was used to determine the low-temperature properties of asphalt binders. The results show that aging and low temperature have a negative impact on the low-temperature properties of asphalt binders. The anti-aging agent improves the low-temperature properties and aging resistance of asphalt binders. Compared with other indexes, the critical cracking temperature Tc and the critical temperature difference ΔTc are more suitable for analysing the effect of aging on the low-temperature properties of asphalt binders. Also, the ΔTc shows the three-stage decreasing rule of 'fast-slow-fast', with the inflection points. It meant that the low-temperature properties of asphalt binders had been altered at the inflection points, which provided a favourable reference to research on the optimal maintenance timing of asphalt pavement.