Corroded reinforced concrete columns under simulated seismic loading

An experimental study was conducted to examine the effects of corrosion for seismic performance of reinforced concrete (RC) columns confirming to current seismic guidelines. Six real size specimens were cast and tested under this study. Three columns were corroded up to 10% and 15% of degrees of corrosion, while the remaining three columns were left un-corroded. Column specimens were corroded by using a pre-calibrated accelerated corrosion protocol. After completion of corrosion exposure, specimens were tested under quasi-static lateral cyclic loading. An appropriate axial load was applied to the column before the commencement of simulated seismic testing. Key indicators of seismic performance were recorded and computed to characterize seismic response of all the RC columns. Steel reinforcement was observed to have undergone significant loss in its cross section due to corrosion which resulted in losing the effectiveness of confinement in providing desired deformability to the column section. Corroded RC columns failed in a catastrophic manner and indicated significant reduction in load carrying capacity as well. Results of the investigation show that corrosion of reinforcement may defeat the very purpose of providing transverse confinement in hinge regions of RC columns.