Study on the viscosity and temperature properties of SBS modified asphalts

The viscosity and temperature properties of SBS modified asphalts differ from that of unmodified asphalts. Viscosity measurements based on the current procedure would predict relatively high mixing and compaction temperatures, which may lead to the deterioration of SBS modified asphalts, cause environmental concerns and safety issues. Measurements of SBS modified asphalt viscosity are analyzed, and the viscosity variation of SBS modified asphalt studied. The viscosity of SBS modified asphalt is dependent on temperature and shear-rate. Results show that 150°C is a separation point for the temperature dependency, with the influence of temperature being significant below 150°C and insignificant above 150°C. The shear-rate dependency decreases with the increase of temperature. Therefore, viscosity measurement should correspond with specified shear rate at temperature, which is important for appropriately defining the mixing and compaction temperatures of SBS modified asphalts.