Research On The Performance Of Warm Asphalt Mixture In Tunnel With Feature Of Inflaming Retarding And Smoke Suppression

With the rapid rise of the Midwest,the construction of the high road has also skyrocketed,and the vast mountain road tunnels have been an important part of the process.Compared with the cement concrete pavement,asphalt pavement with good resistance to sliding,smoothness and noise,and easy in maintenance advantage has been widely applied to tunnel pavement.However,there are some problems in the process of use.Firstly,it is the stage of pavement paving.Since the tunnel environment is relatively closed and narrow,the high temperature of hot mix asphalt mixture and the smoke emission are not easy to dissipate,causing serious damage to the construction personnel and machinery.Second,it is the service phase of the road,and the asphalt is a combustible material,which can be easily triggered by accident in the tunnel,which can pose a serious threat to the life safety of the traffic participants.So,it's important to study the properties of the flame-retardant asphalt mixture.In this paper,we further improve the formulation of fire retardant agent in the research group,and the optimal blending ratio of the expansion system with the flame retardant and the inorganic compound flame retardant is determined according to the test of the limit oxygen index and the change of asphalt performance.According to the asphalt mixture workability test to determine the distribution of temperature optimal dosage of mixed agent and temperature effect.The flame retardant mechanism of different kinds of asphalt is conducted by TG test,and the reaction activation energy E of various flame retardant asphalt in the various combustion stages is determined by using the Coats-Redfern model fitting method(CRIM)to characterize the asphalt combustion performance.The results show that the two kinds of flame retardants used in this paper have good flame retardant effect.In the first and third stage of bituminous combustion,the effect of inorganic compound flame retardant is better,and the flame retardant effect is better in the second stage of expansion.Based on the common asphalt pavement tunnel type AC-13,SMA-13,OGFC-13 three mixture high temperature stability,low temperature crack resistance,water stability,the reflection crack resistance were studied.The experimental results show that the three types of road asphalt mixture can satisfy the requirements of specification,SMA asphalt pavement is recommended for three grading type mixes only from road performance considerations.The flame retardant suppression performance of different types of asphalt mixes was evaluated using a CONE test.It was found that that flame retardant effect of the asphalt mixture admixed with the inorganic flame retardant was the most obvious in the combustion prose.the flame retardant effect of the inorganic compound compound flame retardant is superior to that of the expansion system compound flame retardant.In terms of flame retarding performance,SMA is better in suppressing smoke,and OGFC is better in reducing heat release.It is shown that that temperature mix agent and flame retardant can effectively reduce the emission of exhaust gas,the flame retardant is greatly reduced in cost,and the flame retardant smoke suppression effect is good.