Experimental seismic performance of <scp>Carbon FRP</scp> ‐reinforced concrete columns: Experimental evaluation

Abstract Carbon fiber‐reinforced polymer (CFRP) rebars, known for high strength and corrosion resistance, offer significant potential for improving the long‐term performance of concrete structures. Though some pivotal studies have revealed the promising yet brittle performance of fiber‐reinforced polymer‐reinforced concrete (FRP‐RC) members, this study aims to gain a more profound understanding of the failure modes and mechanisms of CFRP‐RC columns. Seven full‐scale columns were thoroughly investigated through cyclic tests, with varied CFRP reinforcement ratios, stirrup spacings, axial load ratios, and concrete properties. CFRP‐RC columns failed brittlely due to CFRP fracture under combined shear‐compressive failure, but achieved over 2.5% drift and strong load capacity. Based on the more distributed cracking and gradual curvature found on CFRP‐RC columns, a modified plastic hinge theory was proposed for deformation capacity estimation. Further analysis also suggests considering the compressive contribution of CFRP rebars in flexural strength calculations. This study provides foundational insights into the seismic behavior of CFRP‐RC columns and underscores the need for broader investigations to unlock their full potential in high strength and low damage.