Study On The Properties Of SBS/ Rubber Composite Modified Asphalt

In recent years,more and more researches on modified bitumen(rubber bitumen,SBS bitumen,etc.)have been done at home and abroad.Compared with matrix asphalt,modified asphalt has great improvement in high and low temperature performance and anti-aging performance,and the price of rubber powder is low,and SBS modifier is widely distributed.The deficiency lies in the problems of poor storage stability and excessive viscosity in the use of rubber bitumen,while SBS modified asphalt has a relatively high comprehensive performance,but its production cost is high and limits the scope of use.Therefore,this paper starts with the effective combination of rubber powder and SBS modifier to prepare SBS/ rubber compound modified asphalt with better performance.The study is carried out from four aspects:Starting with the preparation process of SBS/ rubber composite modified asphalt,the influence of four factors,adding order of modifier,pre treatment of material,shear temperature and shearing time,on the performance of composite modified asphalt was studied.A set of suitable preparation technology for SBS/ rubber composite modified asphalt was determined.Secondly,the influence factors of the properties of SBS/ rubber composite modified asphalt were analyzed,and the effects of five factors,the number of rubber powder,the type of SBS,the dosage of rubber powder,the content of SBS and the selection of stabilizer,were studied respectively.After a lot of experiments,the best formula is determined as follows: the number of rubber powder is 60 mesh,the volume is 18%,the type of SBS is YH791 SBS and the mixing amount is 3.5%.The performance of composite modified asphalt was tested and found that all properties were good.Then,the road performance of SBS/ rubber compound modified asphalt mixture is studied and tested.The results of rutting test show that the high temperature stability of SBS/ rubber composite modified asphalt mixture is close to that of SBS modified asphalt mixture,and the low temperature trabecular bending test shows that the low temperature flexural resistance of SBS/ rubber compound modified asphalt mixture is better than that of the SBS modified asphalt mixture;the composite modified by water leaching and the compound modified by the SBS/ rubber are modified by the water leaching method.It is found that the adhesion of SBS/ rubber composite modified bitumen has good adhesion to ore,and the results of freezing thawing splitting test and immersion Marshall test show that the water stability of SBS/ rubber composite modified asphalt mixture is equivalent to that of SBS modified asphalt mixture.At last,the mechanism of SBS/ rubber compound modified asphalt was studied by microcosmic means such as fluorescence microscope analysis,infrared spectrum analysis and thermogravimetric differential scanning calorimetry(TG-DSC).The results showed that there was almost no chemical reaction between rubber powder,SBS and matrix bitumen in the process of compound modification,and it was a physical miscibility.The thermal stability of SBS/ rubber modified asphalt is superior to that of matrix asphalt.Comprehensive research shows that the SBS/ rubber modified asphalt developed in this paper is a modified asphalt with excellent performance.More and more studies on rubber asphalt at home and abroad in recent years,compared with matrix asphalt,rubber asphalt in high temperature performance and anti aging performance have greatly improved,and the rubber powder source is easy,low price,but there are still poor storage stability,viscosity is too large is not conducive to the construction and other issues.At the same time,SBS modified asphalt has better comprehensive performance,but its production cost is high,which limits its application.Therefore,this paper starts with the effective combination of rubber powder and SBS two modifiers,and produces SBS/ rubber compound modified asphalt with better performance.