Evaluation of Rejuvenated Aged-Asphalt Binder by Waste-Cooking Oil with Secondary Aging Considered

Waste-cooking oil (WCO) has received significant attention regarding rejuvenating aged-asphalt binder (AB) in recent years. Most current studies focused on whether the performance of WCO rejuvenated aged-asphalt binder (WRAB) can meet the requirements without considering the susceptibility to performance change after the reaging process (secondary aging). To evaluate the performance of WRAB under real pavement conditions, this study first evaluated the rejuvenation effect of WCO from the three perspectives of basic physical, rheological, and chemical characteristics. Then, WRAB was secondary aging carried out to evaluate the aging resistance from the rheological and chemical characteristics compared with virgin asphalt binder (VB). The basic physical properties were based on penetration, softening point, ductility, and rotational viscosity. The rheological characteristics consisted of temperature sweep, frequency sweep, linear amplitude sweep (LAS), and bending beam rheometer (BBR) tests. The chemical analysis was composed of Fourier transform infrared spectrometry (FT-IR), gel permeation chromatography (GPC), and differential scanning calorimetry (DSC) analysis. The results indicated that the basic physical properties of AB could be rejuvenated to the level of VB. The WCO had a better effect in rejuvenating low-temperature than high-temperature performance. After secondary aging, WRAB had better rutting resistance and lower phase angle compared with VB. The WRAB had lower yield stress but higher fatigue life—more suitable for light traffic roads—and the WCO could decrease the strain sensitivity of the WRAB. After secondary aging, WRAB had better aging resistance in fatigue life. According to the DSC results, WRAB had better low-temperature performance after secondary aging. Based on the weighted average molecular weight (Mw), WRAB had a larger molecular weight to secondary aging. A good correlation existed between Mw and rheological parameters for the WRAB after secondary aging.