Study On Rheological Properties And Road Performance Of Nano-ZnO-SBR Vulcanized Modified Asphalt

Asphalt pavement is directly affected by wheel load and other factors such as sunlight,temperature,air and rain,resulting in frequent rutting,cracking and water damage,resulting in maintenance costs rising year by year and its service life significantly reduced.In order to improve the performance of asphalt pavement to achieve the purpose of saving maintenance cost and extending service life,it is practical and effective to modify ordinary asphalt by additives.At present,the main modification methods include nano modification,fiber modification,polymer modification,etc,and have achieved quite ideal results in improving road performance.However,asphalt performance is particularly complex,and the modification effect of a single additive is limited.In this paper,based on the modification advantages of polymer materials and nanomaterials,nano-zno is selected to improve the aging resistance of asphalt,and polymer SBR to improve the low temperature performance of asphalt.Through proper vulcanization of SBR,it can be better compatible with asphalt,and the modification effect of additives is analyzed from the two perspectives of composite modified asphalt mortar and composite modified asphalt mixture.In terms of asphalt mortar,nano-Zno-SBR vulcanized composite modified asphalt was prepared by high-speed shear method.Firstly,its high and low temperature performance and construction convenience were preliminatively analyzed based on the needle penetration,softening point,elongation and Brinell viscosity.Then,the aging resistance of the composite modified asphalt was investigated through the residual needle penetration ratio,softening point increment and mass change.Then combined with rutting factor(G*/sinδ)and fatigue factor(G* ·sinδ)in DSR test,the rutting resistance at high temperature and fatigue resistance at medium temperature were investigated respectively.Finally,the cracking resistance at low temperature was evaluated by using the S and m values in BBR test and the maximum tensile stress and strain in DTT test.In terms of asphalt mixture,several modified bitumen with outstanding properties were selected to prepare standard Marshall test pieces.Rut test,low temperature trabecular bending test,freeze-thaw splitting test and other tests were carried out to analyze the road performance of composite modified bitumen mixture under high temperature,low temperature and immersed water conditions.In this paper,a new idea of using nano-zno,SBR and curing agent DTDM for compound modification of asphalt and asphalt mixture is proposed.The optimum dosage of nano-Zno-SBR sulfide compound modified asphalt and the optimum mix ratio of asphalt mixture are given.The high and low temperature performance of asphalt slurry and pavement performance of asphalt mixture are obtained.Finally,it is concluded that the addition of modifier improves the properties of asphalt and asphalt mixture.The results of this study can provide theoretical support and technical reference for the practical application of nano-Zno-SBR vulcanized compound modified asphalt,which has important practical significance for improving the development of new road materials.