## 5 Economic Analysis  
In this section, the economic analysis of SM-OGFC and SBS-OGFC mixture in improving properties is conducted compared normal OGFC mixture. The price ratio PR and performance improvement ration PIR can be calculated by the following equation. The results are listed in Table 10  
Figure 14: **(a) Scanning electron microscope image of granite particles (\(\times\)1000); (b) Scanning electron microscope image of OSW particles (\(\times\)1000); (c) Scanning electron microscope (SEM) image of granite particles (\(\times\)10,000); (d) Scanning electron microscope image of OSW particles (\(\times\)10,000); (e) Scanning electron microscope image of granite particles (\(\times\)60,000); (f) Scanning electron microscope image of OSW particles (\(\times\)60,000).**  
\[PIR=PI_{m}/PI_{OGFC} \tag{6}\]  
where \(P_{m}\) and \(PI_{m}\) are the price and properties of SBS-OGFC and SM-OGFC, \(P_{OGFC}\) and \(PI_{OGFC}\) are the price and properties of the normal OGFC mixture [27].  
It should be noted that when referring to the marked price in China, the prices of unmodified asphalt binder, SBS and silane coupling agent are 4 CNY/kg, 15 CNY/kg and 6 CNY/kg, respectively. The average price of OGFC-16 unmodified asphalt mixture is 0.380 CNY/kg. It can be calculated that the price of graded broken stone of OGFC-16 is 0.197 (value as 0.20) CNY/kg.  
As shown in Table 11, when the 2.5% silane coupling agent is added to the base asphalt and the oil shale waste is used to replace the fine aggregate of the mixtures (SM-OGFC mixture), the pavement performance, including high and low temperature stability, water stability, raveling resistance performance and permeability performance, has an improvement compared to OGFC mixture, while its price is also relatively lower. It is also can be seen that SBS-OGFC mixture has better properties than OGFC mixture, while its price is not rising obviously. Moreover, analyzing the data in Table 11, SM-OGFC has almost the same pavement performance as SBS-OGFC, but has a cheaper price.  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline  & \multicolumn{2}{c}{**Manshall**} & \multicolumn{2}{c}{**Dynamic**} & \multicolumn{2}{c}{\(-\)15\({}^{\circ}\)C} & \multicolumn{2}{c}{**Innession**} & \multicolumn{2}{c}{**Pennability**} & \multicolumn{2}{c}{**Apablit**} & \multicolumn{2}{c}{**Mitture**} \\
**Mixture Type** & **Stability** & **Stability** & **Stability** & **Strength** & **Strength (Mps)** & **Losses (\%)** & **Stability** & **Stability (fm)** & **Coefficient** & **Frice** & **Frice** \\  & **(fa)** & **(train)** & **(MPa)** & **(MPa)** & **(aa)** & **(aa)** & **(aa)** & **(cam)** & **(cm)** & **(cm)** & **(cm)** & **(cm)** & **(cm)** \\ \hline SIR-OCFC & 9.12 & 5250 & 3.71 & 7.465 & 12.8 & 8.21 & 8.16 & 0.28 & 4.52 & 0.382 \\ SM-OCFC & 9.63 & 4072 & 3.87 & 6.842 & 14.2 & 8.1 & 8.29 & 0.24 & 4.05 & 0.363 \\ OCRF & 6.47 & 3340 & 2.74 & 5.202 & 17.4 & 5.73 & 5.84 & 0.19 & 4.00 & 0.380 \\ PIR\({}_{\text{BS-OC}}\) and PR\({}_{\text{BS-OC}}\) & 1.41 & 1.57 & 1.35 & 1.44 & 0.74 & 1.43 & 1.40 & 1.47 & 1.13 & 1.01 \\ PIR\({}_{\text{B-OC}}\) and PR\({}_{\text{B-OC}}\) & 1.49 & 1.49 & 1.41 & 1.32 & 0.82 & 1.41 & 1.42 & 1.26 & 1.01 & 0.96 \\ \hline \hline \end{tabular}
\end{table}
Table 11: Economic benefit analysis.