# Life-Cycle Cost Analysis on Application of Asphalt and Concrete Pavement Overlay
## 3 Analysis and Results
### Economic Analysis  
Table 3 shows the results of analyzing Korean expressway PMS data for asphalt overlay. The life-cycle of asphalt overlay was found to be 5.5 years [2]. For concrete overlay, overseas \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Method**} & \multicolumn{3}{c}{**Non-Reimbursable**} & \multicolumn{3}{c}{**Remuneration**} \\ \cline{2-9}  & \multicolumn{2}{c}{**Number of Lanes**} & \multicolumn{1}{c}{**Speed**} & \multicolumn{2}{c}{**Number of Lanes**} & \multicolumn{1}{c}{**Speed**} & \multicolumn{1}{c}{**Blocking Day**} & \multicolumn{1}{c}{**Bypass Rate**} \\ \hline Asphalt & 2 lanes & 2 & 100 km/h & 2 lanes & 1 & 60 km/h & 1 km road/3 days + 8 h & 10\% \\ Overlay & 4 lanes & 4 & 100 km/h & 2 lanes & 1 & 60 km/h & 1 km road/5 days & 10\% \\ \hline Concrete & 2 lanes & 2 & 100 km/h & 2 lanes & 1 & 60 km/h & 1 km road/5 days & 10\% \\ Overlay & 4 lanes & 4 & 100 km/h & 4 lanes & 3 & 60 km/h & 1 km road/5 days & 10\% \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Variables applied to user cost (use of shoulder). Figure 8: Comparison of the total construction cost of overlay using the shoulder. (**a**) Comparison of total construction user cost using asphalt overlay shoulder (lane 2). (**b**) Comparison of total construction user cost using concrete overlay shoulder (lane 2). (**c**) Comparison of total construction user cost using asphalt overlaid shoulder (lane 4). (**d**) Comparison of total construction user cost using concrete overlaid shoulder (lane 4). data were examined because of an insufficient number of cases of implementation in Korea, and the life-cycle was found to be 11.0 years [26]. These life-cycles of asphalt and concrete overlays were applied, and the economic analysis was conducted for a 20-year cycle, considering long-term performance. Figures 9 and 10 show the results of the economic analysis for each overlay method according to the traffic volumes of two and four lanes for 15.0 km. For two and four lanes under the 20-year cycle, the economic efficiency of concrete overlay was found to be higher than that of asphalt overlay, considering the long-term service life. When shoulder was used, the economic efficiency of concrete overlay could be further improved. The economic efficiency of concrete overlay compared to asphalt overlay according to the number of lanes and traffic volume is summarized in Table 4. \begin{table}
\begin{tabular}{c c} \hline \hline
**Method** & **Life-Cycle** \\ \hline Asphalt overlay & 5.5 years \\ Concrete overlay & 11.0 years \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Overlay life-cycle. Figure 9: Economic analysis by 2-lane overlay method. (**a**) 2-lane 6000 AADT overlay economical (Shoulder X). (**b**) 2-lane 6000 AADT overlay economical (Shoulder O). (**c**) 2-lane 11,000 AADT overlay economical (Shoulder X). (**d**) 2-lane 11,000 AADT overlay economical (shoulder O). Figure 10: Economic analysis by 4-lane overlay method. (**a**) 4-lane 15,000 AADT Overlay Economical (Shoulder X). (**b**) 4-lane 15,000 AADT Overlay Economical (Shoulder O). (**c**) 4-lane 25,000 AADT Overlay Economical (Shoulder O). (**e**) 4-lane 35,000 AADT Overlay Economical (Shoulder X). (**f**) 4-lane 35,000 AADT Overlay Economical (Shoulder O). \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Method** & **Number of Lanes** & **Traffic Volume (AADT)** & **Shoulder Use** & **Cost Difference (\%)** \\ \hline \multirow{8}{*}{Concrete Overlay} & & 6000 & X & 29.0 \\  & 2 & 6000 & O & 39.1 \\  & 2 & 11,000 & X & 27.7 \\  & & 11,000 & O & 34.5 \\ \cline{2-5}  & & 15,000 & X & 24.0 \\ \cline{2-5}  & & 15,000 & O & 31.9 \\ \cline{2-5}  & 4 & 25,000 & X & 20.8 \\ \cline{2-5}  & 4 & 25,000 & O & 26.9 \\ \cline{2-5}  & & 35,000 & X & 19.0 \\ \cline{2-5}  & & 35,000 & O & 23.2 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Concrete Overlay Economic Efficiency.