# Seismic Performance of Ductile Column with Rectangular Hollow Cross-Section in RC Building
###### Abstract  
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  
discussed. However, the cross-section shapes, in the previous studies mentioned above, were circular, and those columns were mainly for the use of bridge structures. Besides, more detailed discussions on the differences between solid and hollow cross-sections seem to be required, and most studies consider somewhat small axial force ratios. [PERSON] et al. [8] carried out an experimental study with circular hollow RC columns; however, they focused on the structural performance under a uniaxial compressive load. [PERSON] et al. [9] also investigated the confinement effect of circular hollow concrete columns subjected to concentric axial compressive loading by analytical study. The structural characteristics and seismic capacity of the rectangular hollow cross-section have been much less investigated than those of circular ones. For RC rectangular cross-sections, [PERSON] et al. [10] employed hollow bridge pier specimens with different axial force ratios, and the load-deflection curve was investigated by experimental and numerical studies. [PERSON] et al. [11] carried out cyclic bilateral loading tests with hollow cross-sectioned specimens and reported high ductility and a viscous damping ratio even under the bilateral loadings. Previous studies [12; 13] have also focused on rectangular hollow cross-sections, and the seismic capacity of old bridge columns was investigated. [PERSON] et al. [14; 15] conducted dynamic shaking table tests, and the seismic performance was investigated under axial force ratios of 0.05 and 0.1. [PERSON] et al. [16] and [PERSON] et al. [17; 18] studied the evaluation method of the load-displacement relationship for rectangular cross-sections, through experimental and analytical studies. [PERSON] et al. [19] carried out an analytical study on the structural performance of internally confined hollow RC columns with a polygonal cross-section. [PERSON] et al. [20] studied the optimization design method of RC-elevated water tanks under seismic loads, where the column had a rectangular hollow cross-section. Nevertheless, in most cases, detailed comparisons of solid and hollow cross-sections have seemed to be somewhat insufficient, and relatively small axial force ratios, less than 0.2, were adopted. Moreover, the previous studies mentioned above mainly focus on bridge pier, high-speed railways, wind towers, etc. ; therefore, the cross-section details, such as the arrangement and regulations of the reinforcement, the cross-tie, and the size, would be quite different from the RC columns of building structures. Focusing on RC buildings, conventionally, the reduction of self-weight has been achieved by increasing the material strength and reducing the cross-sectional area of members [21]. In the case of secondary members, the self-weight reduction has been achieved by providing slabs with void space and using autoclaved lightweight aerated concrete for non-structural walls [22; 23].