Structural Performance of Flexural and Shear-Deficient Pre-cracked Reinforced Concrete Beams Retrofitted with Knitted Glass Fabric-Reinforced Cementitious Matrix

Abstract This study investigates the retrofitting of concrete structures to restore and enhance the load capacity of deteriorated structural members using external strengthening techniques. The novelty of the study is the use of agro-industrial waste as a binder for fiber-reinforced polymer (FRP) sheets. Experimental testing and finite-element analysis (FEA) are performed to evaluate the effect of glass fabric-reinforced cementitious matrix (GFRCM) on the flexural and shear deficiencies of pre-cracked, retrofitted reinforced concrete (RC) beams. ANSYS software is used for FEA to analyze the load–deflection behaviour of the retrofitted RC beam, facilitating a comparison with experimental results. The results indicated significant enhancements in structural performance, with load-carrying capacity increases between 2% and 32%, and deflection ranging from 4% to 22%. These improvements in load-carrying capacity are attributed to the use of double layers of GFRCM, which effectively improves the load-carrying capacity and overall performance. The FEA predictions aligned well with the experimental findings, confirming that increasing the number of GFRCM layers significantly enhance the structural capacity of retrofitted RC beams.