Effectiveness of carbon textile reinforced concrete in shear strengthening short-span corroded reinforced concrete beams

This paper will present the shear behavior of the corroded stirrups reinforced concrete (RC) beams strengthened with textile reinforced concrete (TRC). The shear resistance contributions from the corroded RC beams and carbon TRC at various volume ratios were carefully examined. Eighteen beams were tested, including twelve subjected by an electrochemically accelerated aging technique for 60 and 90 days to obtain the theoretical mass loss in their stirrups of 10% and 20%, respectively. The stirrups were locally corroded in the shear span. After the corrosion accelerating treatment, corrosion cracks on concrete surfaces were marked, and their widths were measured to observe their distributions. A three-point bending test was applied to obtain the shear performances of the corroded beams subjected to the monotonic and repeated loading. Eight corroded RC beams were strengthened using 2 and 3 U-wrap layers of bidirectional carbon textile. The shear behavior will be discussed, including the ultimate capacity, failure mode, load-deflection, load–strain relationship, and crack distributions. Compared to the controlled specimens, the averaged shear strength of corroded specimens decreased by 16.08% and 25.34%, corresponding to the degree of corrosion ranging from 12.3% to 23.6%. The experimental results also demonstrate that the shear capacities of the corroded RC beams strengthened with carbon TRC had been improved 60.6% compared to the severely corroded controlled specimens.