Study On Modification Of Asphalt Rheology And Aging Properties By Nano-ZnO-OMMT Composites

During the asphalt pavement construction phase and during service,factors such as light,oxygen,heat and water gradually deteriorate the performance of the asphalt material.The modification of asphalt materials with different kinds of modifiers is an important way to improve the performance and service life of asphalt pavement.In this paper,nano-ZnO-OMMT composites were prepared by nano-ZnO and organic montmorillonite(OMMT),and the composites were used to modify the asphalt.The rheological properties,thermo-oxidative aging properties and photoaging properties of the composite modified asphalt were studied by DSR,BBR,FTIR and AFM tests.Research indicates:(1)The results of micro-morphology analysis of nano-ZnO-OMMT composites show that the ZnO particles in the composites can be uniformly dispersed and adhered to the surface and interlayer of OMMT,and the agglomeration of nano-ZnO is not obvious.The segregation test showed that the 1%OMMT+3%ZnO composite modifier had better compatibility with the asphalt than the 3%ZnO or 3%OMMT alone.(2)Nano-ZnO-OMMT composite modifier can impro-ve the resistance of matrix asphalt and SBS modified asphalt to shear deformation,and the high temperature performance of 3%OMMT+3%ZnO composite modified asphalt is the best.The nano-ZnO-OMMT composite modifier has little effect on the low-temperature performance of asphalt,and the low-temperature performance of 1%OMMT+3%ZnO composite modified asphalt is better than matrix asphalt.(3)After thermal oxygen aging and photoaging treatment,nano-ZnO-OMMT composite modifier can inhibit the formation of oxygen-containing functional groups in asphalt,and effectively slow down the aging process of matrix asphalt and SBS modified asphalt under the action of light,oxygen and heat..In addition,as the degree of aging deepens,the "bee phase structure" of the asphalt gradually destroys,and the microscopic phase transitions from a multi-phase state to a single phase state.Combined with AFM roughness analysis,the degree of aging of 1%OMMT+3%ZnO composite modified asphalt is lower than that of matrix asphalt.The gray correlation entropy analysis between microscopic factors and macroscopic rheological parameters shows that the correlation between microscopic factors and phase angles is the best.