Effect of styrene butadiene styrene and desulfurized rubber powder on asphalt modification: Preparation, performance enhancement, mechanism analysis

The aim of this study is to propose a desulfurized rubber powder / styrene butadiene styrene (DRP/SBS) composite modified asphalt technology by combining the advantages of DRP and SBS. This reduces the production cost of modified asphalt and improves the performance of asphalt. In this paper, orthogonal tests were used to optimize preparation process parameters of DRP/SBS composite modified asphalt. And the physicochemical properties, modification mechanism of composite modified asphalt had been thoroughly studied. Subsequently, the results showed that the optimum content of DRP and SBS modifiers are 25 % and 2 %, respectively. The suitable preparation process is to add SBS first, then DRP, while shearing at 5000 r/min for 50 min. In addition, DRP/SBS composite modified asphalt has better high-temperature performance, viscosity-temperature characteristics, aging resistance, and storage stability. Meanwhile, the storage stability of the composite modified asphalt was verified by fluorescence microscopy test. Through the Fourier transform infrared spectroscopy test, it was observed that the composite modified asphalt modification process is a compatible and stable modification of physical and chemical coexistence. Overall, the composite modification method achieves recycling of waste tires while improving pavement performance, thus promoting the sustainability of pavement.