Research On The Properties Of Asphalts And Asphalt Mixture Modified By Trinidad Lake Asphalt And Styrene-butadiene Rubber

Trinidad Lake Asphalt(TLA)has attracted domestic and foreign scholars’ attention because of its good road performance.It is mainly used in airport runway,bridge deck pavement and expressway modification,but its low temperature resistance is limited to its popularization.The properties of Styrene butadiene rubber(SBR)are similar to those of Nature asphalt,which can greatly improve the low temperature cracking resistance of asphalt mixture.At present,the research of TLA and SBR composite modified asphalt and asphalt mixture is rarely seen.Therefore,considering the respective characteristics of the two kinds of modifiers,this paper puts forward a scheme to improve it with the combination of SBR and TLA.The main contents of this article are as follows.In this paper,modified asphalt was successfully prepared basing on AH70 petroleum asphalt with the TLA(5%,10%,20% and 30%)and styrene butadiene rubber(0%,2%,3% and 4% respectively)were used as modifiers.Different proportions of TLA/SBR composite modified asphalt were prepared by high speed shear mixing process.The performance changes of asphalt before and after modification were studied by conventional tests,rheological tests and aging tests.The results show that compared with the matrix bitumen and the single modification,the high temperature performance and the recoverable deformability of the composite modified asphalt have been significantly improved,the low temperature ductility is obviously increased and the temperature sensitivity of asphalt has been reduced in varying degrees.Compared with the single modification of TLA,the TLA/SBR compound modified asphalt has a smaller low temperature stiffness model.Volume and better stress dispersion ability,and asphalt anti aging performance has also been significantly improved.According to all indicators,the best scheme is SBR3%+TLA20%.At the same time,the AC-13 asphalt mixture was prepared with aggregate of five modified schemes of 70,TLA20%,SBR2%+TLA10%,SBR2%+20%TLA and SBR3%+TLA20%.And used the Marshall test,rutting test,low temperature splitting test,water immersion Marshall and freeze-thaw split test to evaluate the high temperature performance,the low temperature performance and water stability of composite modified asphalt mixture The results showed that compared with the 70 matrix asphalt and TLA single modification,the high temperature performance of theTLA/SBR composite modified asphalt mixture was better,the low temperature stiffness modulus decreased,the low temperature performance was effectively improved and the water stability was better.