Improving the aging resistance of SBS modified asphalt with the addition of highly reclaimed rubber

Abstract

Highly reclaimed rubber (HRR)/SBS modified asphalt (HRRMA) technology is planned to endow the advantage of aging resistance of HRR to SBS modified asphalts. The effect of content and type of HRR, reclaim degree and vulcanization on morphologies, physical properties and aging behavior of SBS modified asphalt were investigated. The characteristics and distribution of major functional groups of HRRMA before and after thermal aging and UV aging were analyzed by infrared spectrum. Rheological properties of HRRMAs are characterized by using dynamic shear rheometer (DSR). Addition of HRR in SBS modified asphalt showed increase in penetration values before and after short term aging and UV aging. HRR reclaimed at higher temperature showed increased compatibility with asphalt, resulting in the increase of ductility, better thermal and UV aging resistance. Rheological properties of modified asphalt changed significantly after aging. Moreover, the morphologies of HRR modified asphalt showed it has better compatibility between SBS and HRR. Crosslinking further enhanced the ductility and aging resistance, whereas less increased the processing viscosity of the modified asphalt. The use of HRR in SBS modified asphalt is not only a cost-effective way to recycle waste rubbers but also improve the aging resistance and physical properties.