Analysis of Adhesion Between Asphalt and Aggregate Based on the Infiltration Parameters and Surface Energy Theory

In order to solve the problem of lacking the quantitative evaluation of asphalt and aggregate adhesion, optical contact angle measuring instrument, liquid surface tension measuring instrument, and automatic mercury intrusion instrument were used to measure the contact angle of asphalt and aggregates, the surface tension of asphalt and the pore distribution of aggregates. Infiltration parameters and surface energy parameters of asphalt and aggregate were calculated and the adhesion was analyzed. Besides, the influencing factors of adhesion between asphalt and aggregate were analyzed, and the relationship between the surface tension and temperature of asphalt was established by combining theoretical and experimental results. The results show that the infiltration parameters and surface energy parameters can be used to evaluate the adhesion. Larger porosity and average pore diameter are beneficial to adhesion. Greater depth and shorter time are favorable to infiltration. The adhesion is positively correlated with adhesion work and wetting work. The adhesion between asphalt and aggregate is related to the surface tension of asphalt, the contact angle between asphalt and aggregate, and the surface characteristics of aggregate.