Study On The Water-damage Of Asphalt Pavement Under Hydrodynamic Pressure

Dynamic state water, including hydrodynamic pressure on the road surface and The void water pressure in the pore of pavement structure, is the important reasons of asphalt pavement water-damage. Road surface dynamic water erosion lead to pavement asphalt membrane peeling, aggregate particle spalling,which Is an important cause of producing rut under traffic. Under the Internal pore water pressure,the erosion, pump suction, extrusion of Moving water erode the road structure and reduce the strength of the structure, the integrity of the structure.At present, the research on the water damage of asphalt pavement under the effect of pore water pressure is mainly focused on numerical simulation, which is the lack of measured data. In addition, due to the measurement method is not reasonable or low response frequency and other factors, a small number of existing measurement experiments, the results are not satisfactory. there is no systematic research on The propagation law of pore water pressure in asphalt pavement which shows the regularity of periodic attenuation. At present, there is no authoritative system experimental method and evaluation index for the water damage of asphalt pavement under the dynamic water erosion. Domestic research focuses on the development of the corresponding experimental equipment which can produce dynamic water scouring, and then through the equipment study the change of the asphalt mixture index. These devices have a common drawback, that is, could not simulate high-speed car.The paper establishes a simplified model, calculates the pore water pressure generated in the internal voids of asphalt pavement under certain conditions, and analyzes the propagation law of pore water pressure and the influence factors. The measurement method of pore water pressure is developed. The method has a small disturbance to the pavement structure and the high survival rate of the sensor, and the measurement results are accurate. Through this method, the pore water pressure of asphalt pavement structure under different vehicle speed is measured and the periodicity of the pore water pressure is analyzed by the principle of water hammer wave. The indoor asphalt surface layer material moving water erosion test equipment is developed, which integrates the temperature control system, the dynamic water system, the speed simulation system and so on. The evaluation index of water damage of asphalt mixture is put forward——Pit depth。The effect of silane coupling agent on the water stability of asphalt mixture was analyzed by the new evaluation index.