Seismic Performance of Ductile Column with Rectangular Hollow Cross-Section in RC Building

In order to reduce the self-weight of RC buildings and increase cost-savings, the seismic performance of rectangular hollow sectioned columns was investigated by experimental and analytical studies. Cyclic loading tests were carried out under compression axial force ratios from 0.16 to 0.3, and hysteresis curves, failure patterns, strain distributions of reinforcement, flexural and shear deformations, and energy absorption capacity were discussed in detail. Based on the experiments, under an axial force ratio of 0.16, the structural performances between hollow and solid sectioned columns were found to be almost equivalent. When the axial force ratio increased to 0.3, the structural performance was almost the same until the 2.0% drift angle; however, sudden deterioration of the load-bearing capacity occurred, with concrete compressive failure at the plastic hinge region near the column end. By means of numerical investigations by cross-sectional and FEM analysis, it was found that such brittle failure was induced by the neutral axis location and the concrete stress concentration on the hollow cross-section. Therefore, the appropriate separation of the hollow section from the plastic hinge region is recommended when the neutral axis is located beyond the flange at the ultimate flexural state