## 4 Axial Load-Bearing Capacity of Concrete-Filled Steel Tubes
### Circular Composite Sections
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline
**Ref.** & **L (mm)** & **D (mm)** & **T (mm)** & **f\({}_{\text{y}}\) (MPa)** & **f\({}_{\text{c}}\) (MPa)** & **P\({}_{\text{exp}}\) (kN)** & **P\({}_{\text{pred}}\) (kN)** & **P\({}_{\text{exp}}\)/P\({}_{\text{pred}}\)** \\ \hline
[28] & 914.4 & 152.4 & 1.55 & 331 & 21 & 682.4 & 666.0 & 0.98 \\
[28] & 914.4 & 152.4 & 1.55 & 331 & 25.9 & 721.5 & 751.9 & 1.04 \\  & 914.4 & 152.4 & 1.55 & 331 & 25.9 & 733.1 & 751.9 & 1.03 \\ \hline
[20] & 480 & 150 & 0.7 & 248.2 & 22.5 & 538.0 & 487.3 & 0.91 \\
[20] & 800 & 150 & 0.7 & 248.2 & 22.5 & 513.5 & 512.2 & 1.00 \\  & 480 & 150 & 0.7 & 248.2 & 33.7 & 743.8 & 676.2 & 0.91 \\ \hline
[29] & 750 & 250 & 2 & 260 & 59.5 & 3400.0 & 3101.0 & 0.91 \\ \hline  & 1348.7 & 450.1 & 2.97 & 283.4 & 25.4 & 4413.5 & 5140.8 & 1.16 \\  & 1348.7 & 449.8 & 2.97 & 283.4 & 41 & 6867.6 & 7393.0 & 1.08 \\  & 1348.7 & 450.1 & 2.97 & 283.4 & 41 & 6983.3 & 7401.4 & 1.06 \\  & 716.3 & 238.5 & 4.55 & 578.5 & 25.4 & 3034.1 & 3172.3 & 1.05 \\  & 713.7 & 238.3 & 4.55 & 578.5 & 40.4 & 3582.2 & 3775.3 & 1.05 \\  & 713.7 & 238 & 4.55 & 578.5 & 40.4 & 3646.2 & 3769.6 & 1.03 \\
[30] & 713.7 & 237.7 & 4.55 & 578.5 & 76.8 & 5576.3 & 5134.2 & 0.92 \\  & 1082 & 360.7 & 4.55 & 578.5 & 25.4 & 5631.4 & 5616.4 & 1.00 \\  & 1082 & 360.7 & 4.55 & 578.5 & 41 & 7257.7 & 7069.3 & 0.97 \\  & 1079.5 & 360.2 & 4.55 & 578.5 & 41 & 7043.3 & 7052.5 & 1.00 \\  & 1082 & 360.4 & 4.55 & 578.5 & 84.9 & 11,501.8 & 10,955.3 & 0.95 \\  & 1010.9 & 336.8 & 6.48 & 834.3 & 25.4 & 8472.5 & 8146.4 & 0.96 \\  & 1008.4 & 336.6 & 6.48 & 834.3 & 41 & 9665.5 & 9534.0 & 0.99 \\  & 1010.9 & 336.8 & 6.48 & 834.3 & 41 & 9832.3 & 9545.2 & 0.97 \\ \hline  & 661.5 & 190 & 1.55 & 315.3 & 113.5 & 3260.0 & 3297.2 & 1.01 \\
[31] & 660 & 190 & 1.15 & 184.8 & 113.5 & 3058.0 & 3176.1 & 1.04 \\  & 662 & 190 & 0.95 & 211.2 & 113.5 & 3070.0 & 3234.9 & 1.05 \\ \hline  & 662 & 190 & 1.11 & 203.1 & 110 & 3030.0 & 3106.4 & 1.03 \\  & 656 & 190 & 1.11 & 203.1 & 110 & 2940.0 & 3102.4 & 1.06 \\  & 662 & 190 & 1.11 & 203.1 & 110 & 3140.0 & 3106.4 & 0.99 \\  & 664 & 190 & 1.11 & 203.1 & 94.7 & 2462.0 & 2699.4 & 1.10 \\
[32] & 664 & 190 & 1.11 & 203.1 & 110 & 3055.0 & 3107.7 & 1.02 \\  & 660 & 190 & 1.11 & 203.1 & 110 & 3000.0 & 3105.1 & 1.04 \\  & 664 & 190 & 0.86 & 210.7 & 91.7 & 2553.0 & 2661.7 & 1.04 \\  & 661.5 & 190 & 1.13 & 185.7 & 113.6 & 3220.0 & 3183.4 & 0.99 \\  & 662.5 & 190 & 1.13 & 185.7 & 91.7 & 2630.0 & 2602.5 & 0.99 \\  & 658 & 190 & 1.52 & 306.1 & 91.7 & 2830.0 & 2720.2 & 0.96 \\ \hline  & 664.5 & 190 & 1.52 & 306.1 & 48.3 & 1695.0 & 1600.6 & 0.94 \\  & 664.5 & 190 & 1.13 & 185.7 & 41 & 1377.0 & 1255.7 & 0.91 \\  & 659 & 190 & 0.86 & 210.7 & 41 & 1350.0 & 1271.5 & 0.94 \\  & 663.5 & 190 & 1.52 & 306.1 & 80.2 & 2602.0 & 2426.2 & 0.93 \\
[33] & 662.5 & 190 & 1.13 & 185.7 & 80.2 & 2295.0 & 2297.0 & 1.00 \\  & 663.5 & 190 & 0.86 & 210.7 & 74.7 & 2451.0 & 2196.0 & 0.90 \\  & 661.5 & 190 & 1.52 & 306.1 & 108 & 3260.0 & 3143.3 & 0.96 \\  & 660 & 190 & 1.13 & 185.7 & 108 & 3058.0 & 3033.8 & 0.99 \\  & 662 & 190 & 0.86 & 210.7 & 108 & 3070.0 & 3106.7 & 1.01 \\ \hline \end{tabular}
\end{table} 
Table 4: Circular concrete-filled steel tube tests–axial load.