Study On The Properties Of SBS-HDPE-WTR Compound Modified Asphalt And Its Mixture

Many studies show that waste rubber powder can effectively improve the low temperature performance of asphalt and the anti-aging performance of asphalt mixture.High density Polyethylene(HDPE)is one of the main types of waste plastics,which can effectively improve the High temperature performance of asphalt,but its low temperature performance is poor.SBS modifier has a good effect on improving the high and low temperature performance of base asphalt In order to solve the environmaental problems of waste polymers,such as: "black pollution" and "white pollution",waste rubber powder and waste plastic(high density p olyethylene)are selected as modifiers to improve the performance of asphalt and find some substitutes to replace SBS modifiers,reduce the cost of road construction.The modification properties of the above three polymers were considered comprehensively,using SBS,waste rubber powder and waste plastic(high density polyethylene)as modifiers in this paper,was used to modify common petroleum asphalt,to comprehensively improve the performance of asphalt.First of all,response surface methodology was used to design different mixing ratios,the conventional properties of multicomponent composite modified asphalt with different mixing ratios were studied.The results show that compared with 4%SBS modified asphalt,polypolymer modified asphalt with excellent conventional performance was selected and studied the residual properties of modified asphalt in depth.Secondly,response surface design software was used to design the modified asphalt with different mixing proportion,the basic physical indexes and viscosity characteristics of asphalt were studied,and the modified asphalt with appropriate mixing proportion was optimized.The elastic recovery performance,rheological properties and storage stability of various modified asphalt were analyzed.The modification mechanism of the three composite modified asphalt was studied by infrared spectrometer and fluorescence microscope.It was found that when the amount of waste plastics was about 3%,a new absorption peak appeared,indicating the formation of new substances.We recommend the 1.5S+2H+7.5W,2S+2H+10W,2S+3H+7.5W and 1.5S+3H+10W modified asphalt schemeFinally,according to the performance analysis of SBS/HDPE/WTR composite modified asphalt,four kinds of modified asphalt with better performance were optimized,and the mixing types were respectively 1.5S+2H+7.5W,2S+2H+10W,2S+3H+7.5W and 1.5S +3H+10W.In this paper,the mixed proportion of various modified asphalt was designed by Using Marshall test method,and the high temperature stability,low temperature crack resistance,water stability,fatigue resistance and aging resistance of asphalt mixture were studied.The results show that compared with 4%SBS modified asphalt mixture,SBS/HDPE/WTR composite modified asphalt mixture has better high temperature stability,water stability and fatigue performance.Comprehensive analysis of different performance indicators,the best performance of asphalt is 1.5S+3H+10W modified asphalt.