As asphalt is a viscous liquid, its wetting effect on the surface of gravel directly affects the performance of asphalt mixture. Based on viscous fluid mechanics and surface energy theory, the asphalt spreading process on the gravel surface is analyzed. The results show that the spreading ability of asphalt on the solid surface is directly related to the roughness and complexity of the solid surface. At the mixing temperature, the asphalt can spread freely on the gravel surface. Its adhesion ability on the gravel surface can be evaluated by observing its spreading radius. After the asphalt droplets land on the gravel surface, and being heated for 3 minutes, the spreading is completed and the free energy balance of solid, liquid and gas surfaces is achieved. The limestone gravel has the roughest surface, the most complex pore features on surface, and the smallest spreading radius. The surface roughness of basalt gravel is basically the same as that of andesite surface.
viscous fluid, wetting, spreading, adhesion ability, interfacial tension, surface energy
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