Study On Preparation And Properties Of CR/SBS Composite Modified Asphalt

With the rapid economic development and the surge in traffic volume,the requirements for the use of road infrastructure have become more stringent.How to ensure a high level of pavement service quality has become a major focus of researchers.In recent years,domestic and foreign research in the field of asphalt has mostly been carried out in the development of new modified asphalt.The previously studied SBS modified asphalt has poor anti-aging performance after being exposed to ultraviolet light,which limits the performance of this asphalt.Promotion and application.On the other hand,the increase in traffic volume directly leads to an increase in the number of used tires.In the field of roads,the application of used tires to asphalt mixtures is currently a relatively economical and environmentally friendly approach.This can not only reduce the pressure on waste tire recycling,but also greatly improve the quality of pavement services.However,CR(crumb rubber)modified asphalt has the disadvantages of high viscosity and difficult to construct,and has also been limited by applications.Based on this,this article first performs a single factor test on the factors that may affect the performance of CR / SBSMA(CR / SBS Modified Asphalt),and then selects four factors that have a greater degree of influence to design a four-factor four-level orthogonal test.The analysis of variance was used to obtain the ranking of the influencing factors of different indicators.According to the principle of common consideration of performance and economy,the preparation process and formula of CR / SBSMA were determined.Then,the obtained CR / SBSMA was tested for conventional properties,rheological properties and aging properties,and compared with SBSMA,CRMA and matrix asphalt.Infrared spectroscopy,fluorescence microscopy,and thermogravimetric-differential thermal analysis were used to study and analyze the modification mechanism of CR / SBSMA.Finally,the road performance of CR / SBSMA mixture was tested and analyzed by rutting test and low temperature bending test to comprehensively evaluate the performance of CR / SBSMA.The research shows that:(1)it is difficult to obtain CR / SBSMA with superior performance only by using SBS and CR for compounding modification.The plasticizer ESO is selected to enhance the composite modification effect.According to the results of orthogonal experiments,economic efficiency and performance are considered.Finally,the preparation method and process were obtained.(2)After the conventional and rheological performance tests before and after aging of KL-70,CRMA,SBSMA,CR / SBSMA,it is verified that the CR / SBSMA performance proposed in this paper is better than CRMA,SBSMA,and CR / SBS / ESO composite The modification effect is remarkable.(3)From the test results of FTIR,TG-SDC,and FM,it can be seen that the modification mechanism of SBS and CR is physical mixing,and almost no chemical reaction occurs.The swollen CR and SBS are crosslinked and overlapped in the matrix to form a stable structure.Network-like structure improves CR / SBSMA performance.(4)Compared with the SBS-only mixture,the high-temperature performance,low-temperature performance,and water stability of the CR / SBS composite mixture have been significantly improved.