In order to realize the high-throughput calculation of meso-contact for asphalt mixture skeleton, this paper firstly put forward two contact calculation methods, the neighbor list method and the improved window search method, and then four asphalt mixtures AC13, AC16, OGFC13 and SMA13 were used to compare the difference in calculation accuracy and efficiency among two new methods and exhaustive method, window search method and iPas software, and the range of image resolution that can achieve the balance of calculation speed and accuracy was investigated using virtual specimens. Finally, the applicability of the high throughput calculation method was verified. The results show that neighbor list method can avoid the redundant contact calculation of contact aggregate pairs with the exhaustive method, and the improved window search method can accomplish the purpose of a one loop sweep of the traditional window search method by morphological expansion processing. Neighbor list method, exhaustive method, window search method, improved window search method and iPas software have the same accuracy although there are differences in calculation principles. The order of computational efficiency of different calculation methods is: neighbor list method > exhaustive method > Improved window search method > iPas software > window search method. The decrease of image resolution will improve the speed of contact calculation but reduce the accuracy of contact point calculation results. Considering the requirements of both accuracy and efficiency, a balance of calculation speed and accuracy can be realized when the image resolution range is 0.05~0.075 mm/pixel. The neighbor list method can effectively realize the high throughput characterization of meso-contact of asphalt mixture skeleton.

As one of the common diseases of asphalt pavement, raveling can have a great adverse effect on the durability and road performance of asphalt pavement. To solve the problem of obtaining the asphalt-aggregate interface fracture energy required for asphalt pavement raveling prediction and sensitivity analysis, this research proposed a pendulum impact test method, by which the fracture energy of asphalt-aggregate interface was obtained by conducing lateral shear impact loading on “aggregate-asphalt-aggregate” specimens, causing a negligent failure at asphalt-aggregate interface. The research also analyzed the effects of temperature, asphalt type, aggregate type, water, and mineral filler on the asphalt-aggregate interface fracture energy. The results show that the asphalt-aggregate interface fracture energy can be used as the indicator to evaluate the asphalt-aggregate interface performance, reflecting the asphalt-aggregate adhesion performance, asphalt internal cohesion performance, and the mechanical characteristics of the asphalt-aggregate interface under different temperatures and loading conditions. Temperature has a great influence on the fracture energy of the asphalt-aggregate interface. As the temperature raises, the asphalt-aggregate interface fracture energy shows an upward trend followed by a downward trend, and the adhesion of asphalt and aggregate increases gradually, while the asphalt cohesion decreases. The fracture energy of SBS modified asphalt-aggregate interface and high-viscosity asphalt-aggregate interface are significantly greater than that of 70# asphalt-aggregate interface, while the difference between the fracture energy of the two modified asphalt and aggregate is not significant except for the peak value. The effect of aggregate types on the fracture energy of the asphalt-aggregate interface has no significant rule. Water will reduce the fracture energy of the asphalt-aggregate interface at all temperatures. The addition of mineral filler to asphalt can decrease the interface fracture energy and the range of optimum F/A ratio based on asphalt mixture performance do not have a positive effect on the asphalt-aggregate interface performance probably. The fracture energy of the asphalt-aggregate interface determined by the pendulum impact test can not only serve as a test basis for evaluating the performance of the asphalt-aggregate interface, but also provide material parameters for the numerical simulation analysis of raveling, and provide a criterion for the prediction of raveling and sensitivity analysis, so as to lay the foundation for the precise design of anti-raveling asphalt pavement.

To accurately evaluate the decay process, mechanism and influencing factors of anti-sliding performance of asphalt ultra-thin wear layer after opening to traffic, this study first used arc mold and its supporting wheel grinding mechanism to prepare arc-shaped ultra-thin wear layer specimens. Then, it carried out the accelerated loading test of asphalt ultra-thin wear layer specimens with four gradation types and three asphalt binder grades by driving wheel accelerated loading system. Finally, it scanned the specimens after a certain number of wheel loads by laser texture scanner. Combined with the test data, the macro and micro structure depth decay models of asphalt ultra-thin wear layer based on S-type function were established respectively, and the independent and coupling effects of each porosity and asphalt binder on skid resistance were analyzed based on grey correlation analysis. The experimental results show that the driving wheel accelerated loading system combined with the S-type function model can quantitatively evaluate and predict the evolution process of the performance of the asphalt ultra-thin wear layer. The porosity affects the early decay rate of the macro and micro structural depth of the ultra-thin wear layer. The larger the porosity, the greater the early decay rate of the macro and micro structural depth of the ultra-thin wear layer. The middle and late decay rate of macrostructure depth is more affected by the grade of asphalt binder. The higher the performance grade of asphalt binder, the slower the decay rate of macrostructure depth in the middle and late stages. Void ratio and asphalt binder grade have similar influence on the decay rate of the micro-structure depth of the ultra-thin wear layer in the middle and late stage. Therefore, when designing the anti-sliding performance of the ultra-thin wear layer, it is beneficial to select the opengraded ultra-thin wear layer mixture with large porosity for the anti-sliding durability of the pavement, and the performance grade of asphalt binder can be reasonably selected according to the traffic volume.