Study On Adhesion Between Asphalt And Aggregate Using Surface Energy Theory

Frost boiling, alligator crack, net-shaped crack and pits are commonly found in highway pavement, they are resulted from the moisture damage in the asphalt concrete pavements. To a large extent, the adhesion of the asphalt-aggregate influence on the water stability of the asphalt concrete pavement. Many scholars made research on the moisture damage of the asphalt-aggregate, but the research on the adhesion of asphalt-aggregate was not much based on the surface energy theory. From the perspective of the surface energy, the author made research on the adhesion and the water stability of the asphalt-aggregate and obtained these reserch findings:(1) In the thesis, the domestic and abroad evaluation methods about the adhesion of the asphalt with aggregate were introduced, then the advantage and disadvantage of these methods were analysed. The research on the relationship between the adhesion and the water stability of asphalt and aggregate was made in the thesis. The adhesion is the resistance of the asphalt stripped by water from the aggregate surface and it make the influence on the asphalt mixture water stability. Contacted with the process of the design, construction, maintenance and so on, some measures and suggestions to minimize or delay the emergence of the moisture diseases from the viewpoints of the surface energy theory were proposed.(2) Based on the production and development of the surface energy theory and the surface energy theory apply in various fields especially engineering field, acoording to the Owens-Wendt theory and the nature of the interface between the solid and the liquid, and combined with the Young's equation, the asphalt surface tension and the adhesion work of asphalt-aggregate were calculated in the thesis. Compared with the method in the specification, the advantage and feasibility of the surface energy method to be pointed out in the thesis.(3) The process of adhesion and stripping of the asphalt-aggregate were analysed in the thesis. The stripping process is the reverse process of the adhesion. the adhesion work and the sptripping work were calculated in the thesis, the results corresponded with the actual situation. The compatibility of the asphalt-aggregate, which is characterized by the ratio of the adhesion work and stripping work. The compatibility provide scientific basis for selecting the kind of asphalt and aggregate. The adhesion of the asphalt-aggregate for the water stability of the asphalt mixture is the necessary condition, not the sufficient condition.