Abstract: Using the Box-Behnken’s response surface method and taking the dosages of silane-coupling-agent-modified montmorillonite， SBS， and high viscosity agent （HVA） as influence factors for asphalt， a model was established to determine the optimal dosages of three types of raw materials in the asphalt based on the Brinell viscosity at 170 ℃ as an evaluation criterion. The results indicated that the high-viscosity-modified asphalt containing 5 wt% SBS， 9 wt% HVA， and 8 wt% modified montmorillonite exhibited the best performance， and its penetration， ductility， softening point， and Brinell's viscosity at 170 ℃ were determined to be 4.52 mm， 42.9 cm， 86.1 ℃， and 2.371 Pa·s， respectively. Dynamic shear and Brinell's viscosity tests show that， compared to the pristine asphalt and the high-viscosity-modified asphalt TPS， the addition of modified montmorillonite greatly improved the high-temperature performance and rutting resistance of asphalt， resulting in a significant improvement in the viscosity. The functional groups were analyzed by Fourier-transmission infrared spectroscopy. The disappearance of the vibration peaks indicated that the silane coupling agent involved a chemical reaction with montmorillonite in the modification process.

Key words: modified bitumen, box-behnken, silane coupling agent, modified montmorillonite