Retrofitting of RCC Beams in the Shear Region Using Carbon Fiber-Reinforced Polymer

In recent years, Fiber Reinforced Polymers (FRPs) have gained significant popularity over traditional materials for enhancing the shear strength of Reinforced Concrete (RC) beams, particularly when they are deficient in shear or prone to shear failure. FRPs are advanced composite materials widely used to retrofit existing RC beams and improve the shear resistance of new ones. Among these, Carbon Fiber Reinforced Polymers (CFRP) stand out due to their lightweight nature, exceptional tensile strength, superior corrosion resistance, and ease of application in construction. Shear failure is commonly observed under seismic and impact loading conditions, making CFRP reinforcement a complex but essential solution. Although extensive research has been conducted in this field, existing studies remain insufficient. This study focuses on strengthening RC beams in shear using CFRP. A total of six simply supported RC beams (150 mm × 200 mm × 1800 mm) were subjected to four-point bending tests. The primary objective is to enhance the shear load-bearing capacity of the beams. The research involved testing RC beams reinforced with CFRP, including two control specimens and four beams wrapped with a single layer of CFRP. The wrapping configurations included two beams with 356 mm CFRP wrapping and two with 508 mm wrapping. The average maximum load capacity of the unwrapped beams was recorded at 84.74 kN, while those wrapped with 356 mm CFRP reached 120.46 kN. Meanwhile, the beams wrapped with 508 mm CFRP demonstrated an increased load capacity of 155.815 kN. Cracking was observed earlier in the unwrapped beams compared to those strengthened with CFRP, indicating improved structural performance. The failure patterns of the beams varied, particularly between those with and without CFRP wrapping. This study highlights CFRP's potential and provides a foundation for future research on optimizing its configurations for infrastructure rehabilitation.