Protection effect for polymer-in rich phase in SBS modified asphalt during long-term aging by different MMT/TiO2/SBS pretreatment methods

• Pretreatment methods of MMT/TiO 2 /SBS could precisely protect the PRP of SBSMA from damage during long-term aging. • Long-term thermal-oxidative and UV aging resistance of SBSMA was enhanced effectively by pretreating MMT/TiO 2 /SBS. • Anti-aging effect of the microwave treatment with surface modified nano-TiO 2 is the best. • Compatibility of SBS modifier and asphalt was further improved by these pretreatment methods. To realize the precise protection for polymer-in rich phase (PRP) in Styrene-Butadiene-Styrene (SBS) modified asphalt during long-term aging, the influence of different pretreatment methods (mechanical stirring and microwave treatments) of organic montmorillonite (MMT)/nanometer titania (TiO 2 )/SBS on long-term thermal-oxidative and ultraviolet (UV) aging resistance of SBS modified asphalt (SBSMA) were investigated. Long-term thermal-oxidative aging was simulated using a pressure aging vessel, while UV aging was performed in a UV aging chamber. Rheological properties were assessed using a dynamic shear rheometer with linear amplitude sweep test, and micro characteristics were analyzed using Fourier transform infrared spectroscopy and fluorescence microscopy tests. The results showed that both mechanical stirring and microwave treatments could contribute to the interaction between MMT/TiO 2 and SBS modifier, improve the compatibility of SBS modifier and asphalt, and enhance the fatigue life of SBSMA after long-term thermal-oxidative and UV aging. Compared with the MMT/TiO 2 /SBS modified asphalt without pretreatment, these two pretreatment methods can not only reduce the formation of carbonyl in SBSMA during long-term aging, but also effectively retard the degradation of SBS modifier, and then protect the PRP feature of SBSMA from disappearing. Moreover, after the surface modification of TiO 2 with a silane coupling agent, the effect of microwave treatment is enhanced further. These findings will be conducive to developing a new anti-aging design method of SBSMA.