Study On Anti-sliding Performance Of Tunnel Asphalt Pavement Based On Environmental Factors

With the rapid development of China’s traffic construction,people feel not just more convenient brought by perfect road network,the frequent traffic accidents also let people realize the importance of traffic safety problems.The statistic data show that the accident rate of highway tunnel is equivalent to 1.34 to 8 times of ordinary road section,and 81% accident is related to the lack of skid resistance.With more and more extensive application of asphalt concrete pavement in our country,the research on the skid resistance of asphalt pavement is also paid more and more attention by scholars at home and abroad.There are many factors influencing the skid resistance,but under the fixed road and traffic conditions,the influence factors of skid resistance are only environmental factors such as temperature,rain,snow and road surface pollutants,so it is significant to study the influence of environmental factors on the skid resistance of pavement.Aiming at the tunnel asphalt pavement,this paper mainly studies the influence of temperature,humidity and road surface pollutants on skid resistance of pavement.The paper analyzed the differences of working environment inside and outside of the tunnel through the investigation and research on the working environment(temperature,humidity,illumination,noise,road surface pollution,etc.).We also analyzed the variation regularity of the temperature field in the tunnel through the establishment of the temperature field model of the tunnel asphalt pavement and numerical simulation.On the basis of analyzing the gradation of the asphalt mixture,the paper selects the superpave asphalt mixture as the skid-proof gradation,the material properties such as aggregate mineral properties,mechanical indices and physical properties of aggregates were tested by selecting aggregates.Using the Superpave-13 gradation of the surface layer of the 10-day high speed mountain tunnel in Gansu province,the optimum ratio of oil to rock was determined,and studying the high temperature stability,water stability and low-temperature anti-cracking performance of the mixture,as well as obtaining the mixture gradation which could be used in the subsequent experimental study.The paper studied the effects of temperature,humidity and pavement contaminants on the skid resistance of the tunnel asphalt pavement through the test of the pendulum value BPN by the indoor simulation experiment.The temperature rangeof the air is 0 to 40,the surface temperature range of the road is 0 to 10,and the variation regularity of the BPN of Superpave-13 asphalt mixture at different temperature and different road surface temperature is studied respectively.We also studied he change rule of BPN of Superpave-13 asphalt mixture under different humidity in the range of 0 ~ 100% with 10% humidity change.Based on the measurement index of the existing asphalt concrete anti-slide performance,a new control index is proposed to construct the depth filling rate as the pollutant degree of the road surface,and selected three typical coarse sand,fine sand and lubricating oil to measure the pendulum value of Superpave-13 asphalt mixture under different pollutant filling rate,as well as established the relationship between pendulum value and filling rate.The results show that the pavement pendulum value decreases with the increase of pollutant filling rate,but under the same filling rate,the descending amplitude of the pavement is different,and the order is lubricating oil,coarse sand and fine fine sand.