# Hysteretic Behavior of Steel Reinforced Concrete Columns Based on Damage Analysis
## 2 Description of Test Program  
In this paper, eight SRC frame column specimens were designed and constructed based on the current Chinese standards [53; 54]. All of the specimens have the same cross-sectional shape and dimensions, however they have different compression ratios \(n\) (=0.2, 0.4, 0.6), stirrups ratios \(\rho_{\mathrm{v}}\) (=0.8%, 1.1%, 1.4%), and steel rations \(\rho_{\mathrm{s}}\) (=4.6%, 5.7%, 6.8%). The configurations of the cross sections are shown in Figure 1. The details of all specimens are summarized in Table 1.  
All the steel shape was made of Q235 steel. The concrete strength was C80. The measured concrete cube average compression strength \(f_{\mathrm{cu}}\), axial compression strength \(f_{\mathrm{c}}\), and elasticity modulus of concrete \(E_{\mathrm{c}}\) are 83.9 MPa, 75.49 MPa and 42.042 MPa, respectively. The measured mechanical properties of steel shape, longitudinal rebars, and stirrups are shown in Table 2.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Specimen** & \begin{tabular}{c} **Cross** \\ **Section (mm)** \\ \end{tabular} & **Aspect Ratio** & \
\begin{tabular}{c} **Compression** \\ **Ratios** \\ \end{tabular} & **Steel Shape** &
\begin{tabular}{c} **Stirrups** \\ **Type** \\ \end{tabular} \\ \hline SRC-1 & 150 \(\times\) 210 & 3.0 & 0.4 & 114 & \(\Phi\)6@110 \\ SRC-2 & 150 \(\times\) 210 & 3.0 & 0.4 & 114 & \(\Phi\)6@110 \\ SRC-3 & 150 \(\times\) 210 & 3.0 & 0.2 & 114 & \(\Phi\)6@110 \\ SRC-4 & 150 \(\times\) 210 & 3.0 & 0.6 & 114 & \(\Phi\)6@110 \\ SRC-5 & 150 \(\times\) 210 & 3.0 & 0.4 & 110 & \(\Phi\)6@110 \\ SRC-6 & 150 \(\times\) 210 & 3.0 & 0.4 & 112 & \(\Phi\)6@110 \\ SRC-7 & 150 \(\times\) 210 & 3.0 & 0.4 & 114 & \(\Phi\)6@80 \\ SRC-8 & 150 \(\times\) 210 & 3.0 & 0.4 & 114 & \(\Phi\)8@120 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Design parameters of specimens.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Properties** & \begin{tabular}{c} **Steel Shape** \\ **Flange** \\ \end{tabular} & \begin{tabular}{c} **Stirrups** \\ **Wed** \\ \end{tabular} & \begin{tabular}{c} **Longitudinal** \\ **Rebars \(\Phi\) 10** \\ \end{tabular} \\ \hline Yield strength \(f_{\mathrm{y}}\) (MPa) & 319.7 & 312.4 & 397.5 & 354.5 & 386.3 \\ Tensile strength \(f_{\mathrm{u}}\) (MPa) & 491.5 & 502.5 & 438.0 & 457.3 & 495.7 \\ Elasticity modulus \(E_{\mathrm{s}}\) (MPa) & \begin{tabular}{c} \(2.07\times 10^{5}\) \\ \end{tabular} & \
\begin{tabular}{c} \(2.07\times 10^{5}\) \\ \end{tabular} &
\begin{tabular}{c} \(2.06\times 10^{5}\) \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table}
Table 2: Mechanical properties of the steel and rebars.  
A schematic and a photo of the test setup are shown in Figures 2 and 3, respectively. In order to prevent sliding of the specimen during the test, the specimen was fixed on strong ground by using two support steel beams and two fixed steel beams, which have a certain rigidity as a constraint of the frame column. Each specimen was tested under a constant axial gravity load during the experiment before applying a lateral force \(P\) to simulate seismic loading. The lateral force \(P\) was applied by an electro-hydraulic servo actuator placed at the top of the column. Linear variable displacement transducers (LVDTs) were adopted to monitor the horizontal displacement of the columns.  
The monotonic loading was applied on the specimen SRC-1, and the remaining specimens were subjected to one cycle of loading with displacement ductility \(\mu\) equal to 0.2, 0.4, 0.6, and 0.8, and followed by three successive cycles of loading with the displacement ductility \(\mu\) equivalent to 1.0, 2.0, 3.0,.... until the horizontal load dropped to 80% of the peak load of the specimens or the load could  
Figure 1: Cross-sectional dimensions and distributed steels of specimens (unit: mm).  
Figure 3: Photo of testing apparatus.  
Figure 2: Test setup.  
not be continued because damage was apparent and the loading was stopped [55]. The specific cyclic loading history is shown in Figure 4.