Impact Behavior of CFRP-Strip–Wrapped RC Beams without Stirrups

Abstract

An experimental program was conducted to investigate the shear impact behavior of RC beams without stirrups, and to evaluate the enhancement effects of carbon fiber–reinforced polymer (CFRP)–wrapping retrofit. Eleven RC beam specimens were tested under static and impact loading. Two out of the 11 specimens were control specimens without retrofit, while the rest were retrofitted with CFRP wraps. The effects of varying impact velocity and impact energy on the dynamic behavior were taken into main consideration. This paper discusses the crack patterns and failure modes, time histories of dynamic forces, midspan deflection, accelerations, and CFRP strains. The results show that the CFRP retrofit can enhance the impact resistance of RC beams, significantly reduce their deflection, and limit the damage. The effects of CFRP wrapping for RC beams are found to be different for static and impact loading. The varying impact velocity and impact energy had different effects on the dynamic response and caused changes in failure modes.