Structural Performance of Reinforced Concrete Columns with Bracing Reinforcement

Abstract

In this study, an innovative reinforcement technique is proposed to augment the structural performance of reinforced concrete (RC) columns. The technique involves the introduction of inclined steel ties (bracing reinforcement), connecting longitudinal steel rebars on one side of the square column cross-section at a tie with the longitudinal rebar on the opposite side at the next lower tie. These inclined ties form with the conventional ties and longitudinal rebars a truss structure. The introduced bracing reinforcement effectively enhances the bracing of longitudinal rebars, resulting in substantial improvements in the strength and ductility of RC columns. The study investigates three key parameters using finite element analysis: the pattern of bracing reinforcement, the number of bracings along the column height, and the application of bracing reinforcement under eccentric loading conditions. The findings demonstrate a significant enhancement in yield and ultimate load, stiffness, and ductility of RC columns utilizing this novel technique. Specifically, employing two bracing reinforcements on opposing sides of the column yields the most remarkable structural performance improvement, manifesting in a 32.2% increase in yield load, a 38.7% increase in ultimate load, and a 60.7% augmentation in ductility ratio. Moreover, the study reveals a proportional increase in structural performance improvement with an escalation in the number of bracings within the column height. However, when employing bracing reinforcement under eccentric loading, a reduction in the gain of ultimate strength and ductility, and a corresponding rise in the gain of yield load are observed in comparison to concentric loading conditions.