Experimental behavior of shear deficient RC beams strengthened with CFRP strips against reversible cyclic earthquake load

Abstract This study aims to prevent sudden and brittle shear failures in reinforced concrete beams, which are frequently caused by deficiencies in shear reinforcement. Following the Kahramanmaraş earthquakes in Turkey on February 6, 2023, inspections revealed that many reinforced concrete beams suffered severe damage due to design errors, high shear forces, and secondary effects. These issues are often a result of inadequate shear reinforcement and improper placement. The objective of this study is to enhance the overall load–displacement behavior of reinforced concrete beams with insufficient shear strength under cyclic loading conditions, transforming their failure mechanisms to exhibit ductile flexural failure. The developed strengthening method involves the use of CFRP strips with fan‐type anchors at their ends. This method has been applied to beams with both low and normal concrete compressive strength. The study investigates the maximum load capacity, initial stiffness, displacement ductility ratios, energy dissipation capacities, and overall load–displacement behavior of the tested beams under cyclic loading conditions. The impact of the strengthening method on beam performance is thoroughly evaluated. Additionally, the experimental results are compared with nonlinear finite element analyses conducted using ABAQUS software. The agreement between numerical analysis and experimental results is assessed, evaluating the reliability and accuracy of the finite element model. The findings of this study indicate that the proposed strengthening method is effective in enhancing the performance of reinforced concrete beams.