Study On The Anti-aging Properties Of GO/SBS Composite And Modified Asphalt

In the field of Road Engineering,SBS modified asphalt has been extensively applied in high grade pavement because of its great road performance.However,due to the influence of heat,ultraviolet,oxygen and other environmental factors,SBS modified asphalt is prone to aging during the the production and application,resulting in the ultimately performance degradation.How to improve the anti-aging performance of SBS modified asphalt has become an important technical problem to be solved.This paper based on the properties of nanomaterials and the theory of composite materials,modified the SBS polymer with graphene oxide(GO)nanomaterials,and a GO/SBS composite was prepared by solution blending method.Subsequently,the thermal-ultraviolet-oxygen coupling aging of the GO/SBS composites was carried out,and the aging resistance of the composites was investigated through TG-DTG,GPC and FTIR tests.On this basis,composites with different GO content were used as modifier to prepare GO/SBS composite modified asphalt.Then,the TFOT aging,PAV aging and UV aging were performed on GO/SBS composite modified asphalt to test its basic performance changes.Furthermore,the rheological properties of GO/SBS composite modified asphalt before and after aging were studied by DSR and BBR tests.Finally,FM,FTIR and AFM were carred out to analyze the microstructure changes in the aging process of the modified asphalt,so as to explore the anti-aging mechanism of GO/SBS composite modified asphalt.The performance test results of GO/SBS composites show that the thermal stability decreases after aging,there are molecular chain fracture and polar functional groups generate on the micro-structure.The anti-aging performance of SBS is effectively improved by the addition of GO.For GO/SBS composite modified asphalt,the results of basic properties and rheological properties indicate that the high temperature stability is enhanced with the increase of GO content,but the low temperature performance is weakened.After thermal oxygen aging and ultraviolet aging,the complex modulus G* increases,the phase angle δ and strain recovery rate decreases at high temperature.The creep stiffness increases and the stress relaxation capacity decreases at low temperature.In terms of microstructure,aging leads to the degradation of GO/SBS composites in asphalt,and the generation of polar functional groups such as C=O and S=O.Besides,the “bee structure” and surface RMS roughness decreases in microscopic morphology observed by AFM.By comparing the changes of macroscopic properties and microstructure of GO/SBS composite modified asphalt with different GO content in the aging process,it can be seen that with the increase of GO content,the change trend of macro-properties and micro-structures of modified asphalt decreases.Combined with the aging and degradation principle of SBS modified asphalt,it is speculated that the anti-aging mechanism of GO/SBS modified asphalt mainly includes four aspects: limiting the thermal movement of molecular chain,absorbing ultraviolet radiation,hindering the penetration of oxygen and blocking the chain free radical reaction.