Study Of Crumb Rubber/SBS Composite Modified Asphalt Pavement Performance

At present,the application of asphalt has changed to the modified asphalt.As the most widely used polymer modified asphalt in the present market,the modification technology of SBS modified asphalt has become mature.However,this kind of asphalt always has the problem of poor anti-aging performance.The SBS modified asphalt pavement was oxidized and degraded after UV irradiation,which leads to the early disease of asphalt pavement.The pavement performance of the modified asphalt was seriously affected.Therefore,looking for good anti-aging performance of alternatives has become an important direction of current research on the modified asphalt.With the rapid development of China's auto industry,crumb rubber obtained from the waste tire processing is also increasing.Use of waste tire crumb rubber has become an important method to improve the environmental pollution.Using crumb rubber for asphalt modification to improve asphalt pavement performance is an effective way for resource utilization.At the same time,using crumb rubber for asphalt modification and making it reach the corresponding technical indicators require higher dosage.This results in high viscosity crumb rubber modified asphalt.To deal with this situation,generally the engineering has to improve the mixing temperature.This has increased the difficulty of asphalt pavement construction.Therefore,to reduce the viscosity of asphalt has become the current research focus of crumb rubber modified asphalt.After a long period of research,it found that using crumb rubber and SBS for asphalt modification can obtain standard composite modified asphalt,at the same time can enhance the anti-aging performance of asphalt and reduce the mixing dosage of the powder which could reduce the viscosity of asphalt.Therefore,powder/SBS composite modified asphalt has become the optimal solution to the above problems.However,in the case of the laboratory have been prepared better performance composite modified asphalt,because of lacking experimental data related to asphalt mixture,there is no way to knowwhether the composite modified asphalt can be used in the practical engineering.This study adopted preparation technology of additives activated powder/SBS composite modified asphalt explored in previous work separately prepared powder content of 9.4%,SBS content of 2.4%,Powder content of 7.6%,SBS content of 2.4% and the powder content of 7.6%,SBS content of 2.8% three composite modified asphalt.At the same time,the SBS modified asphalt with SBS content of 4.5% was prepared as the control group.According to GTJF40-2004 gradation requirements to select AC-13 aggregate gradation which was used in the above layer of Asphalt Pavement.In accordance with the experimental specifications of JTGE20-2011,the above three kinds of composite modified asphalt,SBS modified asphalt and matrix asphalt are used for mixture experiments.And then discussed the influence of changes in the content of crumb rubber and SBS on the performance of asphalt pavement,evaluated the advantages of composite modified asphalt with respect to the road performance of SBS modified asphalt.And the application of the conventional mixture design method to the composite modified asphalt mixture is discussed.The results show that,1.common asphalt mixture mix design method is not suitable for crumb rubber /SBS composite modified asphalt.2.Crumb rubber /SBS composite modified asphalt compared with SBS modified asphalt has obvious advantages in the low temperature anti-cracking performance.3.The high temperature and water stability performance is equivalent to that of SBS modified asphalt.