Influence Of Temperature And Pressure On Water Diffusion Characteristics Of Asphalt Concrete

Water damage is a common problem in China’s asphalt pavement,and the prevention and control of pavement water damage is also a worldwide problem.At home and abroad,the asphalt pavement is generally evaluated by its ability to freeze and thaw or soak water.Because the cause of water damage is more complicated,the external role of the road surface is complex and variable,so the evaluation system has a large deviation from the actual situation.This paper studies the water damage of pavement from the perspective of water diffusion of asphalt pavement.The degree of diffusion of water into the asphalt mixture can reflect the ease with which the asphalt pavement is damaged by water.The water diffusion coefficient,as a parameter of the asphalt mixture,can reflect the degree of moisture entering the interior of the asphalt concrete.In this paper,water intrusion into the interior of asphalt concrete is taken as the entry point,and the water diffusion coefficient is used to reflect the water diffusion performance of the asphalt pavement,which in turn reflects the water damage resistance of the asphalt pavement.In this study,a test method was designed to simulate the moisture,temperature and vehicle load(pressure)acting on the asphalt pavement.A test device was designed to ensure that the experimental material can be subjected to water-temperature-pressure three.Simultaneous effects of conditions.This test method is more realistic and the results are more accurate.In the aspect of calculation of water diffusion coefficient,the empirical formula for calculating water diffusion coefficient was modified,and the problems such as over-dependence on experimental data,constant quantity and complexity of calculation in the empirical formula were solved,and a simple and accurate calculation formula for water diffusion coefficient was summarized.In terms of the analysis of test results,the conclusion is drawn that the increase of pressure will lead to the increase of water diffusion coefficient of asphalt concrete and its components.In addition,when temperature and pressure are coupled to asphalt concrete and its composition,the increase of either side or both will lead to the increase of water diffusion coefficient of asphalt concrete and its components.