Cyclic performance of corroded reinforced concrete short columns strengthened using carbon fiber-reinforced polymer

Abstract

Steel corrosion in reinforced concrete (RC) members significantly degrades their structural performance, and such corroded members are typically strengthened using fiber-reinforced polymer (FRP). In this study, the cyclic performance of short corroded columns of RC strengthened with carbon FRP (CFRP) is investigated. Seven short RC columns were fabricated and tested under cyclic loading. Of them, six specimens were corroded and one was uncorroded. The parameters considered included the number of CFRP strengthening layers (zero, one, 1.5, and two) and the type of fine aggregate (river sand and sea sand). The hysteretic curves, failure modes, and load–strain relationships of the specimens were compared and are discussed in detail. Furthermore, the equation for calculating the shear resistance of FRP-strengthened short RC columns in Chinese code has been modified to predict the shear resistance of the corroded RC columns strengthened with CFRP. The results show the following: (1) The deformability and energy dissipation of the corroded specimens without CFRP strengthening were significantly lower than those of the uncorroded counterpart. (2) Through CFRP strengthening, these values were improved and were even higher than those of the uncorroded specimen. (3) The modified equation can predict the shear resistance of CFRP-strengthened specimens.