|
With the rapid development of expressway construction in China, more and more road tunnel will be built in the next decade. The inner space of the tunnel is strait, closing, and with serious noise pollution, concentrated vehicle and great traffic flow. The vehicle is frequent slowdowning and accelerating at the tunnel intake port, which may easily result in traffic accident. Once vehicle be in trouble and bring fire, the flowing and diffusing flammable liquid may overspread firebehaviour and serious threat the life of staffs and other vehicle. The asphat pavement is beautiful, comfortable driving, convenient maintenance and become main road pavement material. Now, asphalt pavement construction mostly adopts hot mix type, the internal temperature is far higher than open construction temperature and with permeating fume. Therefore, in order to supply correlation technique support for tunnel construction, it needs to exploit a kind of environment-protecting, energy-saving, flame-retarded, noise reduction and skidding resistance multi-functional asphalt pavement material (WAFNA).The research is based on National High Technology Research and Development Program "The physical design and pavement technology of skidding resistance, flame-retarded and noise reduction multi-functional asphalt pavement material" and Hubei province traffic hall science and technology project "The optimal design and project account of high-performanced and multifunctional asphalt pavements". Contrapose the needs of skidding resistance, flame-retarded and noise reduction, and the problem of high energy consumption, high construction temperature, and be done on the composition, structure and performance of environment-protecting and energy-saving asphalt pavement. Such main achievements of this paper are:Based on the technique of asphalt viscosity reduced, research the influence of the asphalt viscosity by asphalt viscosity reducer, analyze the mechanism of action of viscosity reducer through IR and DTA, and research the effect on the high-temperature property, low-temperature property, thalposis performance and aging resistance by viscosity reducer. Using colloid mill, the warm and high viscosity modified asphalt is prepared by SBS, compatilizing and viscosity increasing material. The 60℃viscosity is 76000Pa-S,135℃viscosity is 2.2 Pa-S,5℃ductility is 45 cm, isolation soft point is 0.8℃, and toughness is 22N-m.Bring out multilevel interlock design method, used warm and high viscosity modified asphalt, AM-ZD flame-retarded breeze and MF-AFR flame-retarded mineral fibre, and research the pavement performance and mechanical property at different molding temperature. At 135℃molding temperature, the dynamic stability could climb to 8200 times/mm, the Cantabria Loss is lower than 3%, run off loss is 0.1%, the ratio of freeze thaw split strength is more than 90%, and shear strength is 0.71MPa, which are approach to the pavement performance of SMA while the construction temperature lower more than 20℃. In addition, the average sound absorption is 0.418 and texture depth 1.5mm, far exceeded that of SMA. And in the miniature fire tests, the gasoline was escaped more than 80%. The temperature was below 200℃on the surface, while the flash point was low. Its fire-retarding performance reach two safety level, which could satisfy the requirements of comfort and security for the large road tunnel projects.The temperature parameter and the construction techniques of WAFNA, including temperature parameters, mixing, paving and rolling, were studied, and the construction technics of a new pavement material brought forward. The research achievement were applied to Hubei Wuying Highway Mengmengshan tunnel and Hurongxi Yanwan tunnel, of which the construction temperature was lower more than 20℃, greatly improved the construction environment, and reduced energy consumption. The field test result showed the texture depth of WAFNA is over 1.6mm, the noise level is 4dB(A) lower than normal asphalt pavement, which is a new tunnel asphalt material with great application value.
|