# Effect of Waste Engine Oil and Waste Cooking Oil on Performance Improvement of Aged Asphalt
## 1 Introduction
[17] evaluated the effects of WCO viscosity and acid value on the basic, rheological, and chemical properties of typical rejuvenated asphalt. The experimental results indicated that WCO qualities influenced the rejuvenation behaviors of aged asphalt significantly, and that WCO with higher qualities tended to achieve better rejuvenation effects. Recently, [PERSON], [PERSON] [18] conducted a study using natural oils, including WCO and recycled motor oils, as potential natural regenerators. It was found that 3-4% of the WCO could restore the physical properties of the original asphalt binder compared to 20% recycled oil. [PERSON] et al. [19] investigated the efficiency of bitumen rejuvenator investigated through Powder X-ray Diffraction analysis and T2-NMR spectroscopy. The results demonstrated that the HR (an oleic acid-based rejuvenator) additive effectively reconstituted the correct balance between asphaltenes and maltenes, resulting in a reactive colloid network. [PERSON] [20] discussed the rejuvenation effects of WCO on the rheological, microscopic, and chemical characterization of RAP binders. The results demonstrated that adding WCO could restore the rheological properties and reproduce the surface microstructures of aged binders. [PERSON] [21] studied the physical properties and structure of WCO-rejuvenated asphalt and WEO-rejuvenated asphalt. It was found that both waste oils could significantly reduce sulfoxide groups S=O and carboxyl groups C=O in aged asphalt. These conclusions indicated that WCO or WEO in suitable contents could rejuvenate aged asphalt to achieve the properties of original asphalt and meet all physical requirements. In summary, WEO and WCO could both have positive effects on recovering aged asphalts properties to the original asphalt level with addition of a suitable content. In this paper, the effects of WEO and WCO on the performances of six aged asphalts with different aging times were studied. The physical, chemical, and rheological properties of the six aged asphalts with different WEO and WCO dosages were analyzed. According to the observed improvements on the properties of aged asphalts, optimum dosages of WEO and WCO were proposed. Thin-layer chromatography with flame ionization detection (TLC-FID), Fourier-transform infrared (FTIR) and dynamic shear rheometer (DSR) tests were conducted to further evaluate the regeneration effects of WCO and WEO. Though some researches indicated that waste oil could rejuvenate aged asphalts, little research has been conducted to investigate different effects of different oils using comparative analysis and to identify shortcomings of some waste oils to rejuvenate aged asphalt. The objective of this paper was to investigate properties improvement of aged asphalt with WEO or WCO and analyze different improvement effects to illustrate which waste oil can lead to better rejuvenated asphalt. This project could lay the foundations for the application of WEO or WCO in the asphalt recycling field and was also an effective attempt to recycle the waste oils and waste asphalt concrete.