## 6 Performance of Retrofitted Column against Vehicle Impact
### Performance of Column with RC Jacket
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Column (\(\rho_{s}\))**} & **Jacket Thickness (mm)** & **Longitudinal Reinforcement in Jacket** & **Shear Reinforcement in the Jacket** & **Car Impact Velocity (km/h)** & **Maximum Deflection (mm)** & **Residual Deflection (mm)** \\ \hline \multirow{4}{*}{C300 (\(2.6\%\))} & \multirow{2}{*}{40} & \multirow{2}{*}{4 \(\upd\)10.0} & \multirow{2}{*}{\(\upd\)10@150 mm} & \multirow{2}{*}{40} & \multirow{2}{*}{4.16} & \multirow{2}{*}{0} \\ \cline{3-3} \cline{5-6}  & & & & & & \\ \cline{2-6}  & & & & & & \\ \cline{2-6}  & & & & & & \\ \cline{2-6}  & & & & & & \\ \cline{2-6}  & & & & & & \\ \hline \multirow{4}{*}{C400 (\(2.6\%\))} & \multirow{2}{*}{40} & \multirow{2}{*}{8 \(\upd\)12.0} & \multirow{2}{*}{60} & \multirow{2}{*}{1505.0} & \multirow{2}{*}{1.46} & \multirow{2}{*}{No residual deformation, some cracks in the jacket} \\ \cline{3-3} \cline{5-6}  & & & & & & \\ \cline{1-1} \cline{3-3} \cline{5-6}  & & & & & & \\ \hline \multirow{4}{*}{C400 (\(1.13\%\))} & \multirow{2}{*}{40} & \multirow{2}{*}{8 \(\upd\)10.0} & \multirow{2}{*}{80} & \multirow{2}{*}{1505.0} & \multirow{2}{*}{1.46} & \multirow{2}{*}{No residual deformation, some cracks in the jacket} \\ \cline{3-3} \cline{5-6}  & & & & & & \\ \cline{1-1} \cline{3-3} \cline{5-6}  & & & & & & \\ \hline \multirow{4}{*}{C400 (\(2.6\%\))} & \multirow{2}{*}{40} & \multirow{2}{*}{8 \(\upd\)12.0} & \multirow{2}{*}{80} & \multirow{2}{*}{1505.0} & \multirow{2}{*}{1.46} & \multirow{2}{*}{No residual deformation, some cracks in the jacket} \\ \cline{3-3} \cline{5-6}  & & & & & & \\ \cline{1-1} \cline{3-3} \cline{5-6}  & & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Performance of columns with RC jackets against car impact. Figure 19 shows the displacement history at the height of 1740 mm of the modified columns due to car impact. As shown in Figure 19a, the maximum displacement of modified column C300 for an impact velocity of 40 km/h is significantly less than that of the column without the RC jacket. Furthermore, at the end of the impact event, no residual (permanent) deformation exists in column C300 with the RC jacket, up to an impact velocity of 40 km/h. Similar to the modified C300 column, the modified C400 column performed significantly better than the original C400 column. The modified C400 column can withstand an impact velocity of 60 km/h without any permanent deformation, as can be seen in Figure 19b. This means that the RC jacket is effective at protecting the original core column from car impact damage up to an impact velocity of 40 km/h for column C300 and 60 km/h for column C400. The RC jacket acts as a protecting barrier of the original column by increasing the stiffness, shear capacity, and mass [44]. Therefore, in designing a column at the parking places, the above findings on providing an RC jacket can be used as a general guideline to set the vehicle-moving velocities inside the car parking places. When the performance of an AFRP-retrofitted column is compared to that of a column with an RC jacket, it is reasonable to conclude that the AFRP jacket is not as effective as the RC jacket in protecting the column against car impacts.