Analysis of relationship between component changes and performance degradation of Waste-Oil-Rejuvenated asphalt. (23rd August 2021) - Luo, Haoyuan
Highlights: Investigation of performance degradation of three waste-oil-rejuvenated asphalts. Underlying cause of performance degradation identified by SARA fractions analysis. TLC-FID is introduced as an efficient SARA fractions analysis method for asphalt. Abstract: In this study, the underlying causes of the performance degradation of three typical waste-oil-rejuvenated asphalts (i.e., asphalts rejuvenated by waste cooking oil (WCO), waste bio-oil (WBO), and waste engine oil (WEO)) after secondary aging are explored via SARA fractions analysis. The rejuvenation provided by WCO is found to be mainly based on supplementing aged asphalt with saturates, which causes the newly formed colloids to easily lose light components and exhibit low stability. Further, WEO contains some metal residues that catalyze the oxidation and polycondensation process of asphalt. Consequently, the performance of the asphalts rejuvenated separately by WCO and WEO is severely degraded during aging. By contrast, WBO has a stable colloidal structure and lacks ashes; thus, WBO-rejuvenated asphalt exhibits the most stable and reasonable performance degradation in the aging process. Our research suggests that the effect of rejuvenation on aged asphalt cannot be judged only by the difference between the performances of the rejuvenated asphalt and the original asphalt. The performance maintenance of the rejuvenated asphalt during the secondary aging process requires further investigation.