Research On The Influential Factors Of Rubber Asphalt Binder Performance

Crumb tire rubber is the main source of solid waste. It can not only effectively reduce the pollution of the environment and recycling of resources, but also can significantly improve the mechanical properties of asphalt pavement by using the crumb tire rubber powder for asphalt pavement construction. Crumb rubber modified(CRM) binders can improve pavement anti rutting, cracking, water damage resistance and anti-fatigue cracking performance. In addition, rubber asphalt pavement has excellent characteristics such as good flatness, high skid resistance and noise reduction performance, etc. However, the reaction mechanism under different process conditions of rubber asphalt is still unknown at present, which leads to poor performance of rubber asphalt. And CRM binders have not performed as well as engineers had hoped. Therefore, it becomes the key technical problems of rubber asphalt for how to produce asphalt rubber with excellent performance and to explore the mechanism of the reaction under different reaction conditions.First of all, the viscosity, dynamic shear rheometer(DSR), and gel permeation chromatography(GPC) test methods, together with statistical analysis methods were used to study the production process parameters and the internal reaction mechanism of CRM binders based on the research at home and abroad in the paper. Secondly,the gray correlation evaluation model was established to determine the primary and secondary factors affecting the performance of rubber asphalt. Then the optimum process parameters of CRM binders were determined by using statistical analysis methods. Finally, the chemical activation method(namely sodium hypochlorite) was used to study the effect of activation on rubber asphalt performance, including viscosity, rheology and storage stability.The results show that interaction temperature, CRM content, mixing speed and reaction time have significant influence on the performance of CRM binders, so as to LMS. For the base asphalt, the reaction parameters(temperature, time, stirring rate)have less influence on its properties. The impact of primary and secondary factors of asphalt rubber reaction parameters are: powder dosage> reaction time> temperature>speed, which was calculated by gray correlation analysis. And the optimal parameters of rubber asphalt are the interaction temperature is 200℃, the CRM content is 20%, the mixing speed is 2000r/min and the time is 60 min. Crumb rubber activation can significantly reduce the viscosity of the asphalt rubber. But its high temperature stability becomes good, and the activation of the storage stability of rubber asphalt has been significantly improved. The higher the dosage is, the more obvious its improvement.