Performance of RC columns with debonded bars subjected to cyclic lateral loading

Concrete columns with light confinement reinforcement subjected to cyclic lateral load exhibit brittle shear failure along with flexural yielding of longitudinal steel reinforcement bars. The present study investigates the effect of debonding of longitudinal bars on the performance of columns under lateral loading. Column specimens were tested under quasi-static reverse cyclic lateral loading. A comparative study has been carried out on the performance of columns with and without debonding using circular steel tubes of varying lengths. Steel tubes were provided to the longitudinal reinforcement in the potential plastic hinge zone. It is observed that the specimens with debonded reinforcement have significant enhancement in deformation capacity, ductility and energy dissipation capacity than the specimens without it. The congestion of reinforcement at the joints can also be eliminated by reducing the confining reinforcement for these debonded specimens. Copyright (C) 2015 John Wiley & Sons, Ltd.