Flame-retardant Mechanism And Technology Research On Mineral Component In Asphalt Pavement

With the development of road tunnels in our country, traffic accidents increasequickly because the cement concrete pavements' skid coefficient decrease rapidly.And the asphalt mixture pavements are becoming the mainstream in tunnels. Theresearch of the flame-retarded asphalt pavements is valuable. Often-usedflame-retarded asphalt technology with organic flame-retardants has followingproblems: poisonous, smoky, valuable, and influencing asphalt performances. Usingmaterials science principle, this paper firstly brings forward a new technology ofusing mineral powder and mineral fiber with -OH to mix the flame-retarded asphaltpavements.A kind of mineral powder with alkalinity & flame-retardant (MP-AFR) was found.Firstly, its flame-retarded and smoke-retarded performances were validated by limitoxygen index test, horizontal burning test and smoke density test. Then itsflame-retarded and smoke-retarded mechanisms were analyzed by TG-DSC test.Secondly, Compared the quality requirements, It was found that the MP-AFR powdercan replace limestone powder. Thirdly, Visco-elastic of asphalt mortar were studiedby Brookfield viscosity, shear modulus, phase shift angle and rutting gene. Einsteinviscosity theory, Nelson rheology model, Hashin phase shift angle theory were usedin asphalt mortar, this paper brings forward the strengthening viscosity theory ofboundary acid and alkaline reaction. Lastly, Through SMA-13 structure in tunnel thepavement performances and construction performances between the MP-AFR powderand limestone powder were compared.A kind of mineral fiber with alkalinity & flame-retardant (MF-AFR) was found.Firstly, limit oxygen index test with MF-AFR fiber, methyl cellulose and polymerfiber testified that MF-AFR fiber has the flame-retarded function. Secondly,comparing the effect mechanism of 3 kinds of fibers in asphalt mixtures, it was foundthat the MF-AFR fiber could replace another two. Thirdly, the optimal contents ofMF-AFR fiber were 0.4%～0.6% through pavement performances test andconstruction performances test. Lastly, compared the pavement performances andconstruction performances of 3 kinds of fibers, it was testified that their performanceswere equivalent.Finally, the flame-retarded asphalt pavement solutions were put forward. For ACpavements, MP-AFR powder was used. For SMA pavements, MP-AFR powder andMF-AFR fiber were used. It was validated that the solutions have flame-retarded function by SMA-13 pavement outdoors burning test. Then thinking about the tunnelobdurate characteristics, the construction technology was put forward.