Study On The Viscoelastic System Of SBS & Crumb Rubber Compound Modified Asphalt And Its Road Performance

The effective component release of crumb rubber is the precondition for the modified asphalt,and the release process is closely related to the properties of the reaction medium,temperature and reaction time.This research try to make the entire effective component released out from the crumb rubber.The solubility has been used as a characterization method of released degree.Based on the release of the entire effective component,the viscoelasticrheological properties,the ageing performace and construction performance of the compound modified asphalt in different temperature range have been studied.At last,the research results have been verified through practical project.At first,three kinds of asphalt have been used as the medium,and the released degree of the crumb rubber have been reflected by the change regularity of viscosity and solubility.The results show that the effective component release of crumb rubber needs the suitable temperature.It might have a detrimental impact when the temperature is too high or too low.The temperature is higher,the release rate is fast,and its viscosity will also decreased significantly.It shows that the effective component released simultaneously with the depolymerization of polymers.Effects of different media has been studied by the analysis of viscosity changes in different kinds of asphalt.The optimal conditions for the release of the entire effective component in three kinds of asphalt have been found out by selecting the optimized temperature and development time.Based on the release of the entire effective component,the rheological properties of the compound modified asphalt with different amount of SBS in different temperature range have been studied.By the test of viscosity-temperature relationship,Elastic recovery-temperature relationship,measuring-stress ductility,it demonstrated that the polymer component released from crumb rubber enhanced the prosperity of SBS modified asphalt.It makes the compound modified asphalt with better high temperature viscosity in usual pavement temperature range,and good workability at the construction temperature.The condition for the release of the entire effective component and compound modification with SBS can improve the elastic recovery property of the compound modified asphalt in wide temperature range and good relaxation ability under the force.The toughness and tenacity property of asphalt is better,and it increased the bond strength and cohesion performance between asphalt and mixture.The asphalt ageing performance at mix temperature and long-term service have been simulated.It reveals that,modified asphalt is more sensitive with temperature than origin asphalt and the PAV temperature has little influence on two kinds of asphalt.The mix temperature has great influence on the modified asphalt property,so the temperature should not be too high.The ageing performace of the modified asphalt can be improved by choosing suitable asphalt and taking the correct mixing temperature,then you can get the better life cycle cost of the asphalt.The change regularity of adhesion work with temperature shows that the temperature of maximum adhesion work is different with the changing of asphalt and technology.By studying on the temperature of maximum adhesion work for different asphalt and modified asphalt with different viscosity-temperature property,the temperature of maximum adhesion work can use as the optimum mixing temperature.On the basis of the above research,two kinds of compound modified asphalt have been put to pilot production.Performance evaluation of asphalt mixture have also been studied and its practical application effect and value has been verified.