Study on Effects of Aging on SBS Modified Asphalt Based on GPC and Rheological Methods
In order to study the effects of aging on rheological and molecular properties of styrene-butadiene-styrene (SBS) modified asphalt, rheological and gel permeation chromatography (GPC) experiments were conducted on unaged and aged asphalt binders. The results show that the penetration of SBS modified asphalt droped with aging. The softening point of SBS modified as-phalt rises with the aging progress. The molecular oxidative condensation effect exceeds the down regulation effect of SBS degradation, leading to an increasing viscosity. After aging, ductility at 5 °C sharply attenuates and asphalt shows brittleness and no longer meets the requirements for high-grade highway pavement. SBS decomposition can inhibit the aging effect of asphalt molecules. This can restrain strengthening of high-temperature performance and reduction of low temperature anti-crack property of SBS modified asphalt.