Coupling effects of wasted cooking oil and antioxidant on aging of asphalt binders

The service life of asphalt pavement will be reduced with the aging of the asphalt binder. In this study, wasted cooking oil (WCO) and an antioxidant (Tns-(2.4-di-tert-butyl)-phosphite, 168) are utilized to retard aging of 60/80 pen grade asphalt binder and SBS modified asphalt. The influences of short-term aging at high temperature (180°C, 5 h) on physical and chemical properties of asphalt binder with WCO and 168 are investigated. Experimental results showed that aging resistance of asphalt binder with WCO and 168 can be improved effectively. The chemical composition and molecular weight of asphalt binder are distinguished by Fourier transform infrared (FTIR) spectroscopy and Gel Permeation Chromatography (GPC). The results indicated that no new substances are obtained when WCO and 168 added to the asphalt binder. The molecular weight of asphalt binder containing WCO and 168 after aging could be achieved at the level of unaged asphalt binder. Furthermore, grey relational analysis is used to investigate correlation coefficients between increment of carbonyl index (ICI) and increment of softening point (ISP), ductility aging ratio (DAR), penetration aging ratio (PAR), increment of sulfoxide index (ISI) and growth rate of LMS (LAI). The results indicated that ICI, ISI, LAI and DAR are reliable methods to evaluate the aging resistance of asphalt binder.