Study On The Technical Performance Of Warm Mixed Flame Retardant Asphalt And Its Mixture

With the rapid development of China's high-grade highways,there are more and more large and long tunnel projects.Featured by low noise and comfortable driving,asphalt pavement,as a typical pavement structure,is widely used as in highway engineering.Being a combustible material,asphalt must undergo flame-retardant treatment before application in the tunnel pavement works,and therefore,fire safety issues of tunnel asphalt pavement have aroused widespread concern at home and abroad.The warm mix asphalt mixture can solve the problem with high emission and high energy consumption in the process of pavement construction,and can significantly improve the construction environment for tunnel pavement.In order to meet the practical needs of the project,this paper carries out systematic study on the technical performance of the flame-retardant modified asphalt and its mixture,with the main achievements as follows:1?Based on SBS modified asphalt,by using asphalt conventional performance test and Superpave performance test respectively,it studies the technical performance of warm mix flame-retardant modified asphalt,analyzes the influence of different contents of flame retardant and warm mix agent on the asphalt performance,and evaluates the flame retardancy of the flame retardant modified asphalt by the limit oxygen index test.The results show that flame retardant entraining can not only improve the flame retardancy of asphalt,but also enhance its high-temperature performance effectively and increase its PG high-temperature grade,but may have some adverse effect on the low-temperature performance of asphalt.2.In light of the actual project situation,this paper performs the mix proportion design in connection with SBS modified asphalt mixture and warm mix flame-retardant asphalt mixture,studies the pavement performance of asphalt mixture through the high-temperature wheel tracking test,water stability test,low-temperature bending trabecular test and fatigue test,analyzes the effects of different contents of flame retardant on the pavement performance of asphalt mixture,and evaluates theflame retardancy of the warm mix flame-retardant asphalt mixture by the combustion test.The results show that flame retardant entraining can improve the high temperature anti-rutting ability and fatigue performance of asphalt mixture,and has no significant effect on the low-temperature crack resistance of the mixture,but shows some unfavorable influence on the water stability of the mixture.By summary of test results,the best amount of flame retardant is recommended to be 8% of the amount of asphalt.3.Through the comprehensive analysis of the pavement of the test road,it sums up the construction technology of the warm mix flame-retardant modified asphalt mixture,analyzes the energy saving and emission reduction effect of warm mix flame-retardant modified asphalt pavement,and evaluates and analyzes the economic and environmental benefits of warm mix flame-retardant modified asphalt.The research results of this paper have been successfully applied in West Extension Project of Zhongyuan Road,Zhengzhou City,and can provide some technical reference for similar projects.