Effects of steel-to-member depth ratio and axial load on flexural ductility of concrete-encased steel composite columns

This paper experimentally studies flexural ductility of eight concrete-encased steel composite columns. The composite columns are tested under cyclic loading with various axial load levels. In addition to the axial load level, effects of steel-to-member depth ratios on flexural behavior of encased composite members are investigated in this study. Two types of concrete-encased steel composite specimens are designed to represent two steel-to-member depth ratios. Displacement ductility ratios, drift ratios, and plastic hinge rotations obtained from cyclic load tests are used for evaluating flexural ductility of test specimens. Results from this study show that both the axial load level and steel-to-member depth ratio have a significant impact on flexural performance of concrete-encased steel composite columns.