Preparation and Properties of Asphalts Modified with SBS/Organobentonite Blends

The properties of asphalt that had been modified by adding styrene butadiene styrene block copolymers (SBS) and organobentonite clay were investigated. In asphalt mixtures, additives can be bonded to other constituents by using silane coupling agents (SCA). This improves the high-temperature storage stability, rheological properties and after-ageing properties significantly in comparison with pure SBS modified asphalts. The improvement in high-temperature storage stability could be attributed to the organobentonite and SCA decreasing the difference in densities between SBS and asphalt. The organobentonite and SCA contents affected the rheological and low-temperature physical properties. The optimum amount of organobentonite was 2% and of SCA was 1%. These modifications also improved the after-ageing properties of the modified asphalts to some extent.