Stabilized preparation and properties of modified asphalt by desulfurized rubber powder composite SBS
Although rubber powder modified asphalt has been widely used as an excellent hot melt binder for asphalt pavement,there are still problems such as high processing viscosity and poor storage stability.In this study,focusing on the storage stability and rheological properties,using low Mooney and high sol content desulfurized rubber powder,controlling the composite ratio of rubber powder to styrene-butadiene-styrene copolymer(SBS),and optimizing the processing technology,desulfurized rubber powder composite SBS modified asphalt was prepared stably.Its processing performance,high-temperature deformation resistance,thermal stability,and ductility were explored.The research results showed that,(1)Through the sol-gel test and calculation,it was found that the sol content of desulfurized rubber powder was significantly increased,which could effectively improve the compatibility between rubber powder and asphalt.When desulfurized rubber powder was compounded with SBS,it could be seen that the viscosity of asphalt was significantly increased.From the perspective of processing performance,it was necessary to reasonably control the composite content of SBS to ensure the mixing flowability of modified asphalt.(2)Based on the test results of high-temperature performance evaluation,the combination of 20%desulfurized rubber powder+2%SBS and 25%desulfurized rubber powder+2%SBS both had good high-temperature performance.(3)The 48 hour softening point difference was determined through segregation test,and the changes in rutting factor and phase angle at different temperatures were analyzed.Based on the storage stability of desulfurized rubber powder modified asphalt,a modified asphalt scheme of 25%desulfurized rubber powder compounded with 2%SBS was recommended.(4)Starting from ductility,the modified asphalt scheme of 25%desulfurized rubber powder compounded with 2%SBS was ultimately chosen.