Seismic performance of high-strength concrete square columns confined with carbon fiber reinforced polymers (CFRPs)

This paper presents the results of an experimental and analytical study on high-strength, reinforced-concrete (RC) columns with different levels of initial ductility enhanced with carbon fiber reinforced polymer (CFRP) wraps. Six square columns 260 mm wide and 1650 mm long were tested under constant axial load and reversed cyclic lateral load. The test specimens were divided into three groups. Groups I and II were designed and detailed according to the requirements of American Concrete Institute ACI318-02 for intermediate-moment frames. Group I was wrapped with CFRP, group II was control specimens, and group III was designed and detailed according to the requirements of ACI318-02 for special-moment frames. Each group consisted of two columns with ρsl = 1.5% and 3.0% longitudinal steel rebars, where ρsl is the ratio of area of longitudinal reinforcement to gross area of concrete. The moment–curvature is numerically calculated for sections with fiber reinforced polymer (FRP) confinement. The theoretical pre...