Study on the Axial Load Response of RC Columns Confined by CTRC Subjected to Dry-Wet Cycles

Abstract

To investigate the axial load response of reinforced concrete (RC) columns confined by carbon textile-reinforced concrete (CTRC) under chloride attack, 24 CTRC-confined square columns and 12 unconfined columns were tested under axial load, while considering the influences of dry-wet cycles, textile ratios, stirrup ratios, and section sizes. The experimental results indicate that the corrosion resistance and compression performance of RC columns under chloride ion erosion were significantly improved by CTRC. The corrosion of the RC column with CTRC confinement was remarkably reduced with a maximum of 63.9% in the chloride salt environment. The maximum increments of bearing capacity and ductility of CTRC-confined columns were 30.9% and 87.7%, respectively, compared with unconfined columns. In addition, bearing capacity, ductility, and deformation energy were also affected by stirrup ratios and section sizes. Finally, the semi-empirical and semi-theoretical analytical models of the stress-strain relationship and axial-bearing capacity were proposed based on the experimental data and theoretical analysis. The compound confinement effects of CTRC and corroded stirrups on core concrete was considered in the proposed models. The models correlated well with the experimental data.