Effect of Different Metal Oxide/Montmorillonite Nanocomposites on Aging Resistance of SBS-Modified Asphalt

To improve the aging resistance of SBS-modified asphalt (SBSMA), this study prepared two metal oxide/montmorillonite nanocomposites, TiO2/montmorillonite (TM) and CeO2/montmorillonite (CM), and investigated their effects on the rheological properties and microstructure of SBSMA before and after long-term aging. The performance differences between the two nanocomposites under different aging modes were also compared. Conventional physical property tests, dynamic shear rheometer tests (temperature sweep and linear amplitude sweep), dynamic mechanical analysis (DMA), and fluorescence microscopy were employed to evaluate the physical properties, high- and low-temperature rheological properties, fatigue resistance, and the microscopic evolution of SBSMA. The results show that before aging, the incorporation of TM and CM significantly improved the high-temperature deformation resistance of SBSMA, enhanced the SBS polymer dispersion state, and promoted the formation of a continuous network structure of polymer phase. After long-term thermal-oxidative aging, both nanocomposites effectively retarded the aging of the asphalt matrix and the SBS network; CM exhibited superior thermal-oxidative aging resistance. After long-term ultraviolet (UV) aging, both nanocomposites also showed significant protective effects, and TM outperformed CM in UV aging resistance. In summary, TM and CM show differentiated advantages in UV protection and thermal-oxidative protection, respectively, providing a theoretical basis for the design of anti-aging materials for SBSMA based on service environments.