Effect of Hindered Amine Light Stabilizer on Rheological and Aging Properties of SBS Modified Asphalt

Preventing the polymer-modified asphalt from aging is of significance for the promotion of long-life asphalt pavement. This study investigated the effect of the hindered amine light stabilizer (HALS) on improving the aging resistance of asphalt modified with two types of commonly used styrene-butadiene-styrene (SBS). The HALS/SBS modified asphalt was prepared via melt blending. The thin film oven test (TFOT) and ultraviolet (UV) irradiation test were performed to simulate the thermal- and photo-oxidative aging, respectively. The rheological and aging properties of HALS/SBS modified asphalts were investigated through dynamic shear rheometer (DSR). Results indicate that the addition of HALS changes the viscoelastic behavior of SBS modified asphalt depending on the SBS copolymers and testing conditions. It was found that the HALS has significant improvement on both the thermal-oxidative and UV aging resistance for the radial SBS modified asphalt. As for the linear SBS modified asphalt, however, the HALS was found to have noticeable improvement on its UV aging resistance, but very limited improvement was observed on the thermal-oxidative aging properties.