Investigation of RC column confined by rectangular spiral reinforcement through the use of finite element analysis

Abstract

The load carrying and deformation capacity of square reinforced concrete (RC) column confined by rectangular spiral lateral reinforcement subjected to axial load were investigated numerically using abaqus. Thirty one short square RC columns were modeled where seventeen had conventional hoop tie and the remaining fourteen columns had rectangular spiral lateral reinforcement configuration. The configuration, amount and spacing of the lateral reinforcement were included as a factor of confinement in the investigation. Different amounts of lateral reinforcement including 1.4%, 1.6%, 1.8%, 2% and 2.3% were provided in the investigated columns. The diameters of lateral reinforcement used for confinement purpose were 6 mm, 8 mm and 10 mm. The primary objective of this study was focused on the investigation of confinement effect of continuous lateral reinforcement configuration in terms of stress carrying and deformation capacity of confined reinforced concrete columns. RC columns confined with either configuration (hoop or spiral) of lateral reinforcement and provided with the amount of reinforcement in the range of 1.6% to 2% where the spacing to core depth (s/dc) ratio was maintained in the range of 0.4-0.5 had exhibited improved deformation and stress capacity. Accordingly, confined RC columns with rectangular hoop lateral reinforcement had 12% and RC columns with continuous spiral lateral reinforcement had 40% higher deformation capacity compared to RC columns with the same amount and configuration of lateral reinforcement but where the spacing was in such a way s/dc ratio was ≥ 0.5. Clearly, the use of rectangular spiral reinforcement as lateral reinforcement could be considered as a better alternative for lateral reinforcement of short square RC columns particularly, where the deformation capacity is the main importance