# Effect of Waste Engine Oil and Waste Cooking Oil on Performance Improvement of Aged Asphalt
## 4 Results and Discussion
### Chemical Properties
#### 4.5.2 Functional Groups  
The rejuvenated asphalt with 2% WCO was selected for the FTIR microexperiment. Based on the results of the four components, if the rejuvenated asphalt with WCO could improve the asphalt's  
\begin{table}
\begin{tabular}{c c c c c} \hline
**Aging Time** & **5–7 h** & **7–11 h** & **11–13 h** & **>13 h** \\ \hline penetration & 1–2\% & 1–2\% & 2–3\% & 3–4\% \\ softening point & 1–2\% & 1–2\% & 1–2\% & \(>\)2\% \\ ductility & 1–3\% & 1–3\% & 3–4\% & \(>\)4\% \\ viscosity & 1–3\% & 3–4\% & 3–4\% & 4–5\% \\ \hline \end{tabular}
\end{table}
Table 4: Effect of different WCO contents on physical properties in different aged asphalts.  
\begin{table}
\begin{tabular}{c c c c c} \hline
**Aging Time** & **5–7 h** & **7–11 h** & **11–13 h** & **>13 h** \\ \hline penetration & 1–2\% & 1–2\% & 2–3\% & 3–4\% \\ softening point & 1–2\% & 2–3\% & 2–3\% & 3–4\% \\ ductility & 1–3\% & 3–5\% & 4–5\% & \(>\)5\% \\ viscosity & 1–3\% & 3–4\% & 3–4\% & \(>\)4\% \\ \hline \end{tabular}
\end{table}
Table 3: Effect of different WEO contents on physical properties in different aged asphalts.  
\begin{table}
\begin{tabular}{c c c c c} \hline
**Asphalt** & **VA** & **Aged Asphalt (7 h)** & \
\begin{tabular}{c} **Rejuvenated** \\ **Asphalt (3\% WEO)** \\ \end{tabular} &
\begin{tabular}{c} **Rejuvenated Asphalt \\ **(2\% WCO)** \\ \end{tabular} \\ \hline Saturates (\%) & 5.68 & 4.25 & 5.93 & 6.22 \\ Aromatics (\%) & 61.59 & 51.96 & 48.51 & 46.57 \\ Resins (\%) & 20.01 & 26.33 & 29.19 & 31.57 \\ Asphaltenes (\%) & 12.73 & 17.46 & 16.37 & 15.64 \\ \hline \end{tabular}
\end{table}
Table 5: Four components of VA, aged asphalts, and rejuvenated asphalts.  
properties, then so should the rejuvenated asphalt with WEO. The infrared spectroscopy analysis curves of VA, aged asphalt (7 h) and rejuvenated asphalt at wavenumbers between 4000 cm\({}^{-1}\) and 500 cm\({}^{-1}\) are shown in Figure 10.  
As illustrated in Figure 10, the absorption peaks of the aged asphalt (AH-70) and the VA (AH-70) were similar. However, the tensile vibration absorption peak of methane -CH2- of aged asphalt at 2923 cm\({}^{-1}\) and 2851 cm\({}^{-1}\) was enhanced. Carbonyl (C=O) and sulfoxide (S=O) peak area intensities reflected the aging and rejuvenating degree of asphalt. Compared with the VA, aged asphalt exhibited a notable increase in C=O (1600 cm\({}^{-1}\)) and S=O (1031 cm\({}^{-1}\)) peak areas. The absorption peaks indicating aromatics (813 cm\({}^{-1}\) and 865 cm\({}^{-1}\)) were also enhanced.  
The absorption peaks of the rejuvenated asphalt and the VA were also basically similar, while their aromatic absorption peaks were also significantly higher than that of the aged asphalt. However, the rejuvenated asphalt had two new absorption peaks, which appeared at 1746 cm\({}^{-1}\) and 1164 cm\({}^{-1}\), belonging to C=O stretching of carbonyl. The new absorption peaks are the characteristic peaks of soybean oil. Moreover, the oxygenated function (C=O and S=O) peak area intensity of the rejuvenated asphalt showed a notable decrease in carbonyl peak compared to that of aged asphalt. This was due to the proportionality of the decrease in intensity of band from C=O and S=O for recycled asphalts, and decrease in asphaltene content had an effective impact on rejuvenated asphalt performance with WEO or WCO.