Comparative Study of the Mesomechanical Response of Asphalt Bridge Deck Pavement under Multiple Loads

Asphalt bridge deck pavement is a weak bridge structure area, and early damage usually occurs in this area under vehicle loads. Due to the complexity and diversity of vehicle loads and material structures, it is difficult to truly reflect the mechanical response of bridge deck pavement under vehicle loads. This paper studies the vehicle road interaction from a microscopic perspective. In this research, the dynamic response of asphalt bridge deck pavement under multiple loads is comparatively studied, considering the mesoscopic structure of the asphalt materials. First, the compressive properties, tensile properties and interlaminar shear properties of each layer were studied through laboratory tests. Second, the asphalt mixture bridge deck pavement model, including mesostructured, was established. Then, the subprograms of the sinusoidal vibration load, rolling load and vehicle road coupling load were realised using the discrete element method (DEM). Finally, the mesomechanical response of asphalt bridge deck pavement under those three dynamic loads was comparatively studied. The study finds that there is a large difference in the mechanical response of bridge deck pavement under multiple loads. A sinusoidal vibration load can simply be the moving load, the edge of the loading area and the bottom of the lower layer bear large tensile stress, and the shear stress at the edge of the loading area is approximately 4 times that of the middle area. The rolling load can better reflect the status of the vehicle. There is a certain difference in the shear stress response between the rolling load and the sinusoidal vibration load, and the lower layer bears compressive-tensile alternating stress. Under the vehicle road coupling load, the volatility of the dynamic response is obvious due to the road roughness. Therefore, it is of vital importance to improve the abrasion resistance of the surface layer. The results show that the comprehensive consideration of multiple loads and the mesostructure can provide a more reliable method for the dynamic design of bridge deck pavement, which is of great significance for improving the durability of the pavement.