Self-healing Mechanism of Asphalt: Molecular Modeling and Shear-healing Test

Abstract

This study aims to investigate the intrinsic repair behavior of asphalt using molecular dynamics simulation. The Materials Studio software was employed to construct a virgin asphalt and SBS modified asphalt. The evaluation of the two types of asphalt included diffusion coefficient, activation energy of diffusion, and pre-exponential factor. The self-healing performance of both virgin asphalt and SBS modified asphalt was then analyzed and verified through fatigue shear-healing tests. The molecular dynamics results indicate that the self-healing properties of both asphalts improve with increasing temperature. The time required for the cracked area to be filled was found to be shorter than the time needed for the asphalt material to recover its mechanical properties. Furthermore, the activation energy of diffusion for SBS modified asphalt was slightly higher compared to that of virgin asphalt, as observed in the experimental results. The self-healing speed and collision frequency of SBS modified asphalt were both faster than those of virgin asphalt, indicating that the self-healing performance of SBS modified asphalt is superior overall.

Keywords

asphalt binder / molecular dynamics / self-healing / diffusion coefficient

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Wuhan University of Technology and Springer-Verlag GmbH Germany, Part of Springer Nature