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

摘要： 利用分子动力学软件Materials Studio构建老化和未老化的12组分沥青分子模型，以研究在不同模拟温度、老化程度和再生剂掺量下老化沥青的再生机理，并通过沥青动力黏度试验对分子动力学模拟结果进行验证。结果表明：随着温度提升，扩散系数对温度的敏感性降低，增速变缓；再生剂对老化沥青模型扩散系数提升幅度影响大，再生剂在老化沥青中的扩散速度更快；随着再生剂掺量的增加，老化沥青模型扩散系数的增幅减小，当掺量达到10%后扩散系数基本不再升高；老化沥青动力黏度随再生剂掺量的增加而减小，表明沥青流动性增加，扩散性能提升，这与纳微观尺度分子动力学模拟结果一致。

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