Drift-Dependent Confinement Requirements for Reinforced Concrete Columns Under Cyclic Loading

Abstract

The influence of transverse reinforcement and axial load on the drift limit of rectangular columns was investigated using test results from 184 specimens subjected to cyclic loading. Columns within the set were selected to have shear span-to-depth ratios of at least equal to 2.5 so that truss action would be the primary mechanism of shear resistance and the deformation component related to shear would be small compared with that related to flexure. Expressions relating the limiting drift ratio to the axial load ratio and the amount of confining reinforcement were evaluated. Equations indicating the amount of confining reinforcement required to achieve a given limiting drift ratio for reinforced concrete columns in regions of moderate and high seismicity are proposed.