Effect of Bond Property Between CFRP Bar and Concrete on Nonlinear Behavior of Circular CFRP Reinforced Concrete Beams

Abstract

Carbon fiber reinforced polymer (CFRP) bars present advantages over conventional steel rebars such as non-corrosiveness and relatively high tensile strength. CFRP bars cannot directly substitute steel rebars as the main reinforcement for concrete structures due to a lack of understanding of the behavior of CFRP-reinforced concrete (RC) members. This research investigates the effect of surface characteristics of deformed FRP bars on the bond between FRP bars and concrete. Moreover, the research aims to understand how the bond property of FRP bars affects the behavior of CFRP RC beams under shear load. An analysis was conducted for a better understanding of this matter by producing different bond models with a reproductive pull-out test that takes into consideration the surface characteristics aspect of the FRP bar. The structural analysis for CFRP RC beams using the proposed bond models was conducted. It was observed that surface characteristics of CFRP rebars affect the bond-slip curves in a way that the ribbed type presents higher bond strength and greater shear stiffness modulus than the dented type. In addition, the analysis for CFRP RC beams using a ribbed bond model tends to generate steeper diagonal cracks leading to the shear failure in the CFRP RC beams.