Effect of aging on the constitutive models of asphalt and their mixtures

Aging of asphalt and mixture occurs with extension of service time, thereby reducing performance of asphalt mixtures, and causing considerable impact on the function of pavement. This study explored the dynamic mechanical behaviors and constitutive models of SBS modified asphalt and mixtures after different aging methods, including RTFOT (rolling thin film oven test), PAV (pressurized aging vessel), ultraviolet (UV) radiation and field aging for asphalt, and short and long-term aging for asphalt mixture. The effect of aging on dynamic mechanical behaviors and constitutive model parameters were evaluated. The results show that complex modulus of asphalt significantly increases after aging. The relative ranking of aging methods according to the complex modulus of asphalt places RTFOT as the least influential and outdoor aging as the most influential, with the PAV and UV aging falling in-between. Dynamic modulus of mixture shows an increasing trend as degree of aging become more serious. Parameters in Burgers model of asphalt mixture increase overall as degree of aging become more serious except eta(1) at 5 degrees C, indicating enhanced anti-deformation ability at high-temperature and weakened anti-deformation ability at low-temperature. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

This study investigated the dynamic mechanical behaviors and constitutive models of SBS modified asphalt and mixtures after different aging methods. The results showed that the complex modulus of asphalt significantly increased after aging, while the dynamic modulus of mixture showed an increasing trend with aging. Parameters in the Burgers model of asphalt mixture generally increased with aging, indicating changes in anti-deformation ability at different temperatures.