| The addition of Albania rock asphalt can enhance the high temperature stability,water stability and aging resistance of matrix asphalt,but it will reduce the low temperature performance of matrix asphalt,and the addition of rubber powder can enhance the low temperature performance of matrix asphalt.Therefore,this paper attempts to use the Albania rock asphalt and rubber powder as the composite modifier to prepare the Albania rock asphalt rubber powder composite modified asphalt,and analyzes and studies the basic performance,rheological properties,micro mechanism,micro phase state of the Albania rock asphalt rubber powder composite modified asphalt and the road performance of the asphalt mixture,in order to explore a kind of asphalt mixture with good properties High temperature and low temperature performance of modified asphalt.Through the analysis of the basic performance of asphalt,the test results show that the asphalt and rubber powder can improve the stiffness of asphalt and the high temperature performance of base asphalt.The low temperature performance of the base asphalt can be improved by mixing the asphalt and rubber powder in proportion.From the results of Brinell viscosity test,it can be seen that the addition of asphalt and rubber powder can increase the viscosity of the base asphalt and improve the high temperature performance,but if the amount is too large,it will lead to too high viscosity and affect the actual construction.From the comparison test before and after aging,it can be concluded that the addition of Albania rock asphalt and rubber powder can enhance the aging resistance of matrix asphalt.The DSR test results show that the composite modified asphalt has good elastic recovery and high temperature rutting resistance.In order to analyze from the microscopic point of view,Fourier transform infrared spectroscopy and fluorescence microscope were used to analyze the microscopic mechanism and morphology of the compound modified asphalt.The results show that the addition of Albania rock asphalt and rubber powder is mainly physical modification.The rubber powder particles of Albania rock asphalt rubber powder modified asphalt are fully swollen to form large rubber powder particles,and the local spatial network structure is formed through the force of the gel film.With the increase of asphalt content,part of rock asphalt will enter into rubber powder particles to strengthen the local spatial network structure,but when the content of rock asphalt is too large,it will begin to agglomerate.With the increase of rubber powder content,the particle distribution will be filamentous and more local spatial network structure will be formed.Through the analysis of the road performance of asphalt mixture,it can be seen that the dynamic stability of the composite modified asphalt is significantly improved compared with the base asphalt,indicating that its high temperature stability is improved,and the ratio of the residual stability and the freeze-thaw splitting tensile strength of the composite modified asphalt is significantly increased compared with the base asphalt,indicating that its water damage resistance is enhanced,and the water stability is improved Compared with the base asphalt,the maximum bending tensile strain of the composite modified asphalt increases and the bending stiffness modulus decreases,which indicates that the low temperature crack resistance of the composite modified asphalt is significantly improved.By comparing the macro performance and micro performance results of matrix asphalt and composite modified asphalt with different content,and through the road performance verification of asphalt mixture,it can be seen that the composite modified asphalt has the best comprehensive performance when the combined content is 12% Albania rock asphalt + 16% rubber powder. |
