| The warm-mixed antiflaming technology of tunnel asphalt mixture was studied by consulting domestic and foreign literatures、theoretical analysis、laboratory tests、the test road paving, etc in this paper. the warm-mixed antiflaming technology was around the special environment of highway tunnel, aiming at some problems such as the asphalt pavement flammability and releasing harmful gas at high temperature. This technology would have an important significance to improve construction environment and flame resistance of the tunnel pavement.The comprehensive properties of Evotherm was optimal among three mainstream warm-mixed agent products—Sasobit, Evotherm, Aspha-min. Evotherm had a little impact on the asphalt performance; the liquid warm-mixed agent could be obtained to reduce the short-term aging of asphalt by simulating the water-thermal aging process of asphalt and improving RTFOT test; the three methods, Marshall voidage method, SGC voidage method and the mixing torque, were used to evaluate of the cooling rate of warm-mixed asphalt mixture; the SGC voidage method was the optimal evaluation method of Evotherm warm-mixed asphalt (The abbreviation is E-WMA);The surface energy and parameters of asphalt, warm-mixed asphalt and aggregate was obtained by Young-Dupre matrix equation with the lie drop method and capillary rise method.The work of adhesion model of four cases—asphalt-mineral aggregate, warm-mixed asphalt-mineral aggregate, asphalt-water-mineral aggregate, warm-mixed asphalt water-mineral aggregate was established based on the surface energy theory; the work of adhesion of the four situations were calculated through the model and the surface energy parameters of material; the warm-mixed agent would cause irregular effects on the adhesion between asphalt and mineral aggregate at no water, but reduce the adhesion between asphalt and mineral aggregate at water; meanwhile the work of adhesion of warm-mixed asphalt and mineral aggregate showed the same trend as water stability of WMA at water, indicating that the work of adhesion was as a complementary evaluation of mixture water stability;The r&d inorganic composite flame retardant,9#MAA-Ti, could improve the flame resistance of modified asphalt and mixture, and reduce the storage stability of asphalt according to the synergistic principle; it is suggested that the storage time try to be reduced, and its other performances could meet the requirements of specification;The warm-mixed could not occur interact reaction with agent and flame retardants by PH test, and they could be evenly distributed among the asphalt; the warm-mixed agent and flame retardant could improve the flame resistanceof modified asphalt, but make other various properties decline at a small range, still meeting the regulatory requirements;The fractal characteristics of AC aggregate gradation only needed a fractal dimension D to characterize based on fractal theory; and the fractal dimension D had a good linear correlation with volume parameters of warm-mixed antiflaming modified asphalt mixture, fatigue performance, dynamic stability and low temperature bending strain energy; the relationship model could be established to estimate the pavement performance of warm-mixed antiflaming modified asphalt mixture, and verify gradation rationality;The best method of on-site preparation for the antiflaming modified asphalt was drawn to sync with the way of SBS modified by detecting two site production programs; the addition way of Evotherm warm-mixed agent was mechanical automatic control;The PaveCool software was used to calculate the paving temperature recommended of the asphalt pavement under different environmental at30min of effective RCC time and70℃of minimum rolling temperature; the recommended paving temperature was draw to be suitable for the construction of warm-mixed antiflaming modified asphalt pavement via the actual situation of the test road to verify the applicability. |
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