Investigation on recycling of SBS modified asphalt binders containing fresh asphalt and rejuvenating agents

• Recovery asphalt (RA) was obtained from recycle SBS modified asphalt mixture.
• RSMA containing RA, fresh SMA and rejuvenators were prepared.
• Rejuvenator II improve the aging resistance and decrease the viscosity of RSMA.
• Regenerated modified asphalt binder has better aging resistance.

The use of polymer modified asphalt binder in asphalt concrete pavements for over 20 years, large numbers of waste modified asphalt mixture have been produced. In this study, regeneration of waste SBS modified asphalt binder was investigated by adding fresh SBS modified asphalt binder and rejuvenating agents. Effects of content of rejuvenating agent and ratio of recovery asphalt to fresh asphalt on physical properties of regenerated SBS modified asphalt binder were researched. The rheological behavior and short-term aging of regenerated SBS modified asphalt binder was investigated and chemical compound was analyzed using Thin-layer chromatography/flame ionization detection (TLC/FID) and Fourier Transform Infrared (FTIR) Spectroscopy. The results indicated that regenerated SBS modified asphalt binder with both good physical properties and pavement performances was obtained by blending recovered SBS modified asphalt with fresh SBS modified asphalt and rejuvenating agent, and the optimum physical and rheological properties occurred when the ratio of recovery asphalt to fresh asphalt was 35:65 and the content of rejuvenating agent was 5 ∼ 10 wt%. The result of RTFOT indicated that the regenerated SBS modified asphalt binder have good aging resistance, especially rejuvenating agent II was used to reclaimed SBS modified asphalt binder.