The diffusion efficiency of rejuvenator in aged asphalt is an important indicator to evaluate the quality of rejuvenator. In this study, hexadecanamide was selected as a representative molecular structure of bio-rejuvenators. Based on the weight ratio of each component and the number of aged groups, three asphalt binder models were constructed for different aging states. The RDF function was used as an important approach to analyze the states of molecular agglomerations in virgin and aged asphalt binder. To calculate the diffusion coefficient of asphalt reasonably, the asphalt-aggregate diffusion model was constructed in diffusion planes from different directions. The influence of temperature on this process was also considered. The average diffusion coefficient of aged asphalt at the aggregate model surface was lower than that of virgin asphalt. However, under the influence of hexadecanamide, the average diffusion coefficient of aged asphalt showed an increasing trend.

CICTP;molecular dynamics;asphalt binder;Diffusion