Study On The Waste Waterproofing Membrane Used For Modified Asphalt

A kind of qualified heavy traffic paving asphalt and waste waterproofing membrane were used as raw materials in this research,and the possibility of waste waterproofing membrane used as asphalt additive and modifiers was investigated.The asphalt mixtures were prepared by mixing the waste waterproofing membrane with the Qinhuangdao AH-90 base asphalt,and their conventional properties were investigated.It was shown that,when the content of the waste waterproofing membrane was increased,the softening point of asphalt mixture improved and the penetration index enlarged as well as the temperature performance.The penetration and ductility decreased slightly.When the content of waterproofing membrane was 5%~20%,the aging index of the system fluctuated at a small number,indicating the aging degree was not so serious and the whole system was stable.When the content of waterproofing membrane was over 20%,the viscosity of the asphalt mixture increased rapidly,the aging degree was enlarged and the segregation of the asphalt mixture was serious.Based on effects of waste waterproofing membrane content on preparation,aging properties as well as storage stability of asphalt mixture,20% of the waste waterproofing membrane was determined for the maximum capacity of Qinhuangdao AH-90.The different content of SBS(styrene-butadiene-styrene block copolymer),PE(polythene)and SBR(styrene-butadiene rubber)and the different structure of SBS were used to modify asphalt mixture by mixing 20% waste waterproofing membrane with Qinhuangdao AH-90.The properties of SBS-modified asphalt were investigated.It was shown that,with the increasing content of SBS,the penetration of SBS-modified asphalt declined linearly,and the softening point and viscosity increased significantly.In addition,various SBS structure impacted on asphalt mixture differently.The macro performance was that improvements of penetration,softening point,ductility and viscosity of the star structure of SBS-modified asphalt were more dramatical.When content of SBS(star structure)was 4%,the properties of SBS-modified asphalt reached the requirement of SBS-D of Ministry of Transport.Besides,the properties of SBR-modified asphalt were investigated.It is shown that,with the increasing content of SBR,the low temperature performance of SBR-modified asphalt was improved.When content of SBR was 3%,SBR-modified asphalt had a significant increase in the ductility,and SBR particles in the fluorescence microscope also scattered evenly.In addition,the properties of PE-modified asphalt were investigated.It was shown that,with the increasing content of PE,the high temperature performance of PE-modified asphalt was improved.When the content of PE was higher than 4%,the softing point of PE-modified asphalt grew dramatically.When the content of PE was 6%,the softening point reached up to 80℃.The infrared spectroscopy of experiments showed that the characteristic peaks of product were simple superpositions of their raw materials with no new characteristic peaks appearing.Therefore,the processes of various mixings and modifications were physical effect.