[Abstract]Devulcanizaiton of crumb rubber in asphalt matrix was proved to have a negative effect on mechanical properties during the production of Terminal Blend (TB) rubberized asphalt, while the addition of SBS can significantly restore the lost properties through revulcanization reaction. However, the revulcanization reaction was not clear from molecular components to rheological properties. This study investigated the chemical and rheological perspectives of the revulcanization reaction of TB rubberized asphalt enhanced with styrene-butadiene-styrene (SBS) polymer. Gel permeation chromatography (GPC) and fluorescence microscopy were used to characterize the change of molecular weight and morphology during the revulcanization reaction. In addition, Attenuated Total Reflection (ATR) Fourier Transform Infrared (FT-IR) Spectroscopy was performed to characterize the revulcanization behaviors and aging behaviors of TB rubberized asphalt enhanced with polymer. Moreover, dynamic shear rheometer (DSR) was used to conduct dynamic oscillatory test and multiple stress creep recovery (MSCR) test. The test results indicate that the addition of SBS can promote the revulcanization of TB rubberized asphalt while the further addition of polyphosphoric acid (PPA) might 20 have a negative effect. The revulcanization results in increased molecular weight and greatly improves the high temperature performance and elastic properties. Meanwhile, TB rubberized asphalt enhanced with polymer offers great low temperature performance compared to that of commonly used SBS modified asphalt. Furthermore, TB rubberized asphalt offers better anti-aging properties over SBS modified asphalt since the formation of carbonyl compound and sulfoxide is inhibited during the aging process.
