## 3 Database  
The literature search was conducted to collect published experimental data on the shear transfer of concrete interfaces. To concentrate on the basic shear transfer for the evaluation of design provisions, the database presented in this paper addresses only direct push-off, reinforcement perpendicular to the interface, and interfaces subject to monotonic pure shear loads. The test database included 458 push-off test specimens from nineteen studies. Details of the test programs that meet the data selection criteria in this study are summarized in Table 7. The database arrangement includes the source of test data, test year, interface type, concrete type, number of specimens, compressive strength of concrete \(f_{c}^{\prime}\), and clamping stress \(\rho f_{y}\) (\(\rho f_{y}\) is calculated using the upper limit of the yield strength of the reinforcement \(f_{y}\) for each code). In each test program, the total number of test specimens conducted may be higher than that listed in the table (test specimens that do not satisfy the collection criteria are not included). \begin{table}
\begin{tabular}{l c c c c c c} \hline \hline \multicolumn{1}{c}{**Surface Roughness**} & \(c_{r}\) & \(k_{1}\) & \(k_{2}\) & \(\beta_{c}\) & \multicolumn{2}{c}{\(\mu\)} \\ \cline{4-7}  & & & & & \(f_{ck}\geq 20\) & \(f_{ck}\geq 35\) \\ \hline Very rough \(R_{t}\geq 3.0\) mm & 0.2 & 0.5 & 0.9 & 0.5 & 0.8 & 1.0 \\ \hline Rough \(R_{t}\geq 1.5\) mm & 0.1 & 0.5 & 0.9 & 0.5 & 0.7 & \\ \hline Smooth & 0 & 0.5 & 1.1 & 0.4 & 0.6 & \\ \hline Very smooth & 0 & 0 & 1.5 & 0.3 & 0.5 & \\ \hline \hline \end{tabular} \(R_{t}\) = peak-to-meanline surface roughness.  
\end{table} 
Table 6: Coefficients for different surface roughness. \begin{table}
\begin{tabular}{l c c c c c c} \hline \hline \multicolumn{1}{c}{**Researchers**} & \multicolumn{1}{c}{**Year**} & \multicolumn{1}{c}{**Interface Type**} & \multicolumn{1}{c}{**Concrete Type**} & \multicolumn{1}{c}{**Number of Specimens**} & \(f_{c}^{\prime}\) & \(\rho f_{y}\) \\ \cline{2-7}  & 1969 & M-U & NW & 13 & 26.48 to 31.10 & 0.00 to 9.23 \\  & & M-P & NW & 19 & 16.44 to 29.92 & 1.54 to 9.23 \\ \hline [PERSON] et al. [8] & 1975 & M-U & NW & 2 & 27.82 to 27.99 & 3.81 to 5.65 \\  & & M-P & NW & 2 & 26.58 to 29.10 & 3.74 to 5.43 \\ \[PERSON] [9] & 1976 & M-P & NW & 8 & 40.13 to 42.23 & 1.57 to 13.29 \\  & & J-R & NW & 14 & 17.20 to 41.75 & 1.56 to 10.87 \\  & & J-S & NW & 18 & 40.16 to 42.61 & 1.45 to 10.33 \\ \[PERSON] et al. [10] & 1976 & M-U & NW & 7 & 26.89 to 28.82 & 0.00 to 9.59 \\  & & M-U & SLW & 7 & 25.79 to 29.30 & 0.00 to 9.43 \\ [PERSON] et al. [10] & 1976 & M-U & ALW & 14 & 26.75 to 30.48 & 0.00 to 9.52 \\  & & M-P & NW & 6 & 26.89 to 28.82 & 1.54 to 9.10 \\  & & M-P & SLW & 18 & 13.79 to 41.34 & 1.50 to 9.43 \\  & & M-P & ALW & 14 & 26.75 to 30.48 & 1.51 to 9.68 \\ \[PERSON] [23] & 1993 & M-P & SLW & 18 & 57.16 to 75.98 & 1.94 to 3.94 \\ \hline [PERSON] and [PERSON] [24] & 2002 & M-U & NW & 19 & 46.92 to 123.81 & 1.52 to 6.07 \\  & & M-P & NW & 19 & 46.92 to 113.60 & 1.52 to 6.07 \\  & & J-R & NW & 10 & 80.91 to 104.93 & 1.52 to 6.07 \\  & & J-S & NW & 2 & 83.11 to 98.78 & 1.52 to 3.03 \\ \[PERSON] et al. [25] & 2008 & M-P & NW & 19 & 40.20 to 106.40 & 1.68 to 10.83 \\ [PERSON] [26] & 2010 & M-U & NW & 4 & 24 & 0.00 to 3.22 \\ \[PERSON] [27] & 2010 & J-R & NW & 3 & 42.40 & 2.00 \\  & & J-R & SLW & 6 & 39.51 & 2.00 \\ \hline [PERSON] et al. [28] & 2012 & J-R & NW & 8 & 33.99 & 1.65 to 2.90 \\ \hline  & & J-R & NW & 6 & 33.51 to 52.06 & 5.38 \\  & & J-R & SLW & 6 & 31.58 to 49.64 & 5.38 \\ [PERSON] and [PERSON] [29] & 2014 & J-R & ALW & 6 & 41.92 to 54.08 & 5.38 \\  & & J-S & NW & 6 & 33.51 to 52.06 & 5.38 \\  & & J-S & SLW & 6 & 31.58 to 49.64 & 5.38 \\  & & J-S & ALW & 6 & 41.92 to 54.08 & 5.38 \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Summary of database. All test programs that constitute the database were carried out between 1969 and 2021. The test programs in the database consisted of specimens made of four interface conditions and three concrete types.