Analysis of migration behavior of aggregate-asphalt system based on interface effect of particles

Abstract

The spatial migration of aggregate-asphalt system is the internal manifestation of the shear deformation of asphalt mixture. To elucidate the migration mechanism, five asphalt mixtures were measured by two self-developed testers and a new evaluation method was proposed. The migration behaviors were analyzed based on interface effect involving composite geometric characteristics of coarse aggregates, contact properties of particle system and interface interaction between aggregates and asphalt binder. The results show that the maximum migration shear stress can effectively evaluate the migration behaviors of the aggregates-asphalt system. The migration behaviors of aggregate-asphalt system are predominantly affected by the interface effect which is closely related to the composite geometric characteristics, contact properties and interface interaction. The higher the composite angularity index of coarse aggregates doesn’t mean the stronger the capability of resisting the migration due to the influence of bonding and lubrication effect of asphalt binder. The bonding effect of asphalt has a poor ability to restrict the movement of large-sized fine aggregates, leading to the fine aggregates to significantly interfere with the skeleton structure of asphalt mixture.