关键词: 道路工程；分子动力学模拟；老化沥青；再生剂；扩散系数

Abstract: The molecular dynamics software Materials Studio was used to construct 12 component asphalt molecular models of aged and unaged asphalt, in order to study the regeneration mechanism of aged asphalt under different simulated temperatures, aging degrees, and rejuvenator dosages. The results of molecular dynamics simulation experiments were verified by asphalt dynamic viscosity experiments. The results show that as the temperature increases, the sensitivity of diffusion coefficient to temperature decreases and the growth rate slows down. The effect of rejuvenators on the increase in diffusion coefficient of aged asphalt models is significant, and the diffusion rate of rejuvenators in aged asphalt is faster. As the dosage of rejuvenator increases, the increase in diffusion coefficient of the aged asphalt model decreases. When the dosage reaches 10%, the diffusion coefficient basically no longer increases. The dynamic viscosity of aged asphalt decreases with the increase of rejuvenator dosage, indicating an increase in asphalt fluidity and improvement in diffusion performance, which is consistent with the results of molecular dynamics simulation results at the nano-micro scale.

Key words: highway engineering; molecular dynamics simulation; aging asphalt; rejuvenator; diffusion coefficient