Asphalt Mixture Design Of Noise Reduction Enviroment-friendly Tunnel Pavement

Safe environment asphalt mixture is used in tunnel pavement. It can reduce traffic noise and dust pollution during tunnel construction process, It also can conserve consumption of energy and resources, reduce the occurrence of tunnel fire, improve entirely construction, traffic environment and the performance of tunnel asphalt pavement.Aiming at high noise in the tunnel which makes trouble to drivers and conductors, based on the pavement and tire noise mechanism, effect of different mixture type, mixture void ratio, thickness, and aggregate size was researched by standing wave measuring instrument in the paper. The paper analyzes the pavement noise debasing regularity by considering the above factors. It takes sound absorption efficiency below 1000Hz as evaluation index of absorption ability and makes a analysis of regression about comprehensive effect of various influencing factors by mathematical statistics. Finally, it identify that the big void mixture, maximum grain size of 13mm, thickness of 40mm, void ratio of 20% has the highest sound absorption ability, which sound absorption coefficient of peak value is 53.7%, sound absorption efficiency below 1000Hz is 241 %-Hz.The paper takes void ratio as control parameter of asphalt mixture and confirms that the target void ratio of TESM-13 asphalt mixture is 20% on the basis of structural performance and usability of asphalt pavement. In view of aggregate contact mechanism, it uses filtering filling method to design the proportion of coarse aggregate. Firstly, it takes the minimum of VCA as objective function and seeks the optimum proportion of coarse aggregate. Secondly, it fixes the proportion and makes a combinatorial optimization with the next grade. Finally, it gets the optimum proportion of coarse aggregate. The fine aggregate proportion of each file is used by the traditional calculation method - the n method. The proportion of coarse and fine aggregate is confirmed by theoretical method. The target percentage of void is confirmed by structural behavior and pavement performance of asphalt mixture.The security environment asphalt was used in this paper. Several special performance tests of safety and environmental asphalt mixture which means noise reduction, fire-retardant and antiskid was made in the paper, it also made some traditional performance tests, such as high temperature stability, low temperature crack resistance and water stability performance. The experimental results and the testing road test results demonstrate that the tunnel can fully play its excellent performance and can be designed more perfect asphalt pavements according to the special requirements of the road tunnel.The mixture was applied in the tunnel pavement, which noise is below 6dB than the normal pavement outside tunnel.