Research on TPS-SBS Composite-Modified Asphalt with High Viscosity and High Elasticity in Cold Regions

Considering the harsh service environment of asphalt pavements in cold regions, there is an urgent need to develop high-viscosity, and high-elasticity modified asphalt. This study focuses on the composite modification effects of SBS (Styrene-Butadiene-Styrene) and TPS (TAFPACK-Super) modifiers. A multivariate regression analysis model was established to evaluate the effects of different external additive proportions on the properties of high-viscosity and high-elasticity modified asphalt, including softening point, penetration, ductility, and dynamic viscosity. The results indicate that the constructed quadratic nonlinear regression models exhibit excellent goodness of fit (0.929, 0.994, 0.882, and 0.939), verifying their reliability. The model further elucidates the influence patterns of different materials on asphalt properties: SBS has the greatest impact on the softening point and dynamic viscosity, TPS significantly enhances ductility, while aromatic oil primarily affects penetration. By considering performance and cost, an optimized formulation for TPS-SBS composite-modified asphalt was determined: 9% SBS, 1% TPS, and 3% aromatic oil. Validation tests demonstrate that the modified asphalt prepared with the optimal formulation meets all performance criteria, with a dynamic viscosity of 55.32 × 104 Pa·s at 60 °C. Additionally, this composite-modified asphalt exhibits excellent aging resistance, construction workability, and high-temperature stability, providing scientific support and reference for the development of durable asphalt pavements in cold regions.