Experimental investigations on hybrid strengthening of short reinforced concrete column elements under eccentric compression

This work experimentally investigates the efficacy of hybrid strengthening technique using a combination of near-surface mounted (NSM) carbon fiber laminates and externally bonded (EB) carbon fiber-reinforced polymer (CFRP) wraps for short reinforced concrete (RC) columns under eccentric loads. The performance of the hybrid FRP strengthened column elements was compared with the members strengthened using only NSM CFRP laminates or only EB CFRP wraps. The behavior of columns without and with different types of strengthening under concentric and eccentric compression was also compared. The tests showed that the RC column elements upgraded using hybrid strengthening displayed significant improvement in both the stiffness and strength, especially under eccentric compression. The performance improvement was primarily due to the substantial contribution of NSM laminates to the bending resistance. Existing analytical models were used to validate the observed behavior. The analytical results obtained had a close match when compared to the experimental results.