Study On Road Performance Of Wasted Printed Circuit Board/SBR Composite Modified Asphalt And Asphalt Mixture

In this paper,in order to protect the environment and recycle e-waste,based on asphalt and asphalt mixture technology,the non-metallic powder of wasted printed circuit boards(PCBs)and styrene butadiene rubber(SBR)were used as asphalt modifier to conduct research.Analyzing the basic performance,rheological performance,micro performance,anti-aging performance of PCBs/SBR composite modified asphalt and PCBs/SBR composite modified asphalt mixture pavement performance,aiming to provide theoretical basis and experimental basis for the application of PCBs/SBR composite modified asphalt in actual asphalt pavement engineering.Firstly,PCBs non-metallic powder and SBR were used as raw materials to prepare composite modified asphalt by physical mixing method,and the basic properties of modified asphalt were tested by conventional test methods;Secondly,dynamic shear rheological test was used to characterize the rheological properties of PCBs/SBR modified asphalt with different contents.Meanwhile,based on rheological parameters,the effect of PCBs/SBR composite modifier on asphalt aging resistance was explored;Based on the microscopic test methods of fluorescence microscope and fourier transform infrared spectroscopy,the micro mechanism and aging mechanism of PCBs/SBR composite modified asphalt are explored;on this basis,the indoor marshall test,rutting test and low temperature bending beam test are used to verify the pavement performance of PCBs/SBR composite modified asphalt mixture,and the correlation between asphalt and asphalt mixture performance index is explored based on grey correlation theory.The main conclusions are as follows:(1)The PCBs non-metallic powder can effectively improve the stiffness of asphalt,so as to enhance the ability of asphalt to resist external force,improve the high-temperature performance of asphalt,but reduce the low-temperature performance of asphalt.The addition of SBR can effectively improve the lowtemperature performance of PCBs asphalt.(2)PCBs/SBR composite modifier can effectively enhance the rheological properties of asphalt,which shows that the asphalt has good elastic recovery and high temperature rutting resistance.The change range of PCBs/SBR composite modified asphalt aging evaluation index is relatively small,indicating that PCBs/SBR composite modified asphalt has strong anti-aging ability.(3)With the increase of the content of PCBs,the fluorescence diagram of asphalt changes from uniform dispersion to local agglomeration,which indicates that the compatibility of asphalt decreases,by comparing the fluorescence diagram of PCBs/SBR composite modified asphalt before and after aging with the same content,it is found that PCBs/SBR composite modifier is degraded during aging process;Compared with the base asphalt,PCBs/SBR composite modified asphalt has a new characteristic absorption peak,after asphalt aging,polar functional groups such as carbonyl group and sulfoxide group in asphalt increase,which promotes the high temperature stability of asphalt.(4)Compared with the base asphalt,the residual stability and dynamic stability of PCBs asphalt mixture are higher,while the bending limit strain is decreased,with the addition of SBR,the water stability and high temperature stability of PCBs asphalt mixture are enhanced,SBR modifier can improve the low temperature crack resistance of PCBs asphalt mixture,which is consistent with the change trend of asphalt performance.(5)Based on the grey correlation method,it can be seen that the proportion of double bond area,rutting factor and softening point of asphalt are highly correlated with the high-temperature performance index of asphalt mixture,which can better reflect the high-temperature performance of asphalt mixture,while the correlation between asphalt ductility and flexural stiffness modulus of asphalt mixture is relatively low,indicating that ductility index is not enough to reflect the low-temperature performance of asphalt mixture real performance.(6)Combined with the macro performance,micro performance,anti-aging performance of asphalt and pavement performance of asphalt mixture,the comprehensive performance of PCBs/SBR composite modified asphalt and asphalt mixture are the best when the content of PCBs nonmetal powder is 10%.