Influence of Aggregate and Asphalt Type on the Bond Strength between Asphalt and Aggregates and Its Self-Healing Properties

Abstract

Determining the bond strength between asphalt and the aggregate base material is an intuitive way to ascertain the adhesion. In this study, we determined the bond strength between different types of asphalt and aggregates. First, the influence of these types of asphalt and aggregates on the bond strength was evaluated. Second, the bond strength of lime aggregate-based material and five types of asphalt in dry and immersion states was measured, and the influence of water on the bond strength was investigated. Third, the asphalt was extracted into aromatic, saturated, colloidal, and asphaltene by an asphalt component separation test, and the bond strength between each asphalt component and aggregate was tested. Finally, for the specimens with adhesive failure, the bond strength was retested to evaluate the self-healing ability of the adhesive. The results show that adhesion is influenced by asphalt and aggregate types as well as water immersion. The adhesion between asphalt and aggregate is primarily gum-based, followed by aromatics. After adhesion failure, the adhesion recovers to a certain extent (that is, it self-heals), but the healing rate decreases with the increase in test frequency; the adhesion tends to be stable after the third test.