## 4 Evaluation of Design Provisions
The mean, maximum, and minimum values, standard deviation (STD), and coefficient of variation (COV) of \(v_{test}/v_{cal}\) for each of the specimen groups with the same interface condition are summarized in Table 8. An alternative presentation of these results is shown in Figure 9. Not all design provisions are applicable to all interface conditions. Therefore, when the results are summarized, not applicable (n/a) is shown in these cases. Figure 5: Compressive strength of concrete \(f_{c}^{\prime}\) and clamping stress \(\rho f_{y}\) versus the ratio \(v_{test}/v_{cal}\) (monolithic uncracked interface). Figure 6: Compressive strength of concrete \(f_{c}\)\({}^{\prime}\) and clamping stress \(\rho\!f_{y}\) versus the ratio \(v_{test}/v_{all}\) (monolithic precracked interface). Figure 7: \(Cont.\)  
Figure 8: _Cont._  
Figure 7: Compressive strength of concrete \(f_{c}^{\prime}\) and clamping stress \(\rho f_{y}\) versus the ratio \(\
u_{test}/\
u_{all}\) (interface that is intentionally roughened). \begin{table}
\begin{tabular}{l l c c c c} \hline \hline \multirow{2}{*}{**Codes**} & \multirow{2}{*}{**Statistics**} & \begin{tabular}{c} **Monolithic** \\ **Uncracked** \\ \end{tabular} & \begin{tabular}{c} **Monolithic** \\ **Precracked** \\ \end{tabular} & \
\begin{tabular}{c} **Roughened** \\ \end{tabular} &
\begin{tabular}{c} **Smooth** \\ \end{tabular} \\ \hline \multirow{4}{*}{_AASHTO LRFD_} & Average & 1.65 & 1.08 & 1.49 & 1.57 \\  & Maximum & 3.45 & 1.73 & 3.66 & 2.84 \\  & Minimum & 1.03 & 0.61 & 1.00 & 0.80 \\  & STD & 0.53 & 0.21 & 0.47 & 0.54 \\  & COV (\%) & 31.87 & 19.29 & 31.75 & 34.10 \\ \hline \multirow{4}{*}{_CSA-S6_} & Average & 3.18 & 1.59 & 2.44 & 2.32 \\  & Maximum & 11.41 & 2.91 & 6.91 & 4.21 \\ \cline{1-1}  & Minimum & 1.39 & 0.84 & 1.64 & 1.02 \\ \cline{1-1}  & STD & 2.14 & 0.40 & 0.77 & 0.89 \\ \cline{1-1}  & COV (\%) & 67.31 & 24.85 & 31.60 & 38.64 \\ \hline \multirow{4}{*}{_PCI_} & Average & 2.35 & 1.54 & 2.08 & 2.54 \\  & Maximum & 4.09 & 2.74 & 4.31 & 5.34 \\ \cline{1-1}  & Minimum & 1.37 & 0.72 & 1.26 & 1.07 \\ \cline{1-1}  & STD & 0.70 & 0.37 & 0.57 & 0.99 \\ \cline{1-1}  & COV (\%) & 29.60 & 23.74 & 27.60 & 39.13 \\ \hline \hline \end{tabular}
\end{table} 
Table 8: Statistical analysis of design provisions depending on the interface conditions. Figure 8: Compressive strength of concrete \(f_{c}\) and clamping stress \(\rho f_{y}\) versus the ratio \(v_{test}/v_{cal}\) (interface that is not roughened). Monolithic uncracked: mean values of \(v_{test}/v_{cal}\) summarized in Table 8 indicate that the _AASHTO LRFD_ was the most accurate because the mean value is closest to 1.0, while the _CSA-56_, _PCI_, and _ACI 318-19_ provided more conservative estimates for interface shear resistance (mean \(v_{test}/v_{cal}\) of 3.18, 2.35, and 2.94, respectively). The _AASHTO LRFD_ and _PCI_ codes provided the most stable estimates (the lowest COV values for \(v_{test}/v_{cal}\) were 31.87% and 29.60%, respectively). In contrast, the _CSA-56_ and _ACI 318-19_ provided the most scattered estimates (their COV values for \(v_{test}/v_{cal}\) were 67.31% and 43.39%, respectively). Monolithic precracked: The _AASHTO LRFD_ was the most accurate and consistent due to the lowest mean and COV values for \(v_{test}/v_{cal}\) (1.08 and 19.29%, respectively), but