Finite Element Investigation of the Flexural Performance of RC Beams with Various Dimensions Strengthened Using Prestressed CFRP Sheets

Abstract

In this study, numerical investigation of reinforced concrete (RC) beams strengthened with prestressed CFRP sheets is presented via the finite element (FE) analysis. Due to the high expenses of experimental tests, especially for large real-scale structures, numerical modeling could be an effective replacement. The main achievement of the present study is to give an insight into the flexural behavior of large RC beams retrofitted by prestressed CFRP sheets. The FE model is first verified by recently published experimental results and then implemented for the analysis of large-scale specimens, which are normally seen in RC structures. The effect of mesh size, width and length of CFRP sheets, ductility and stiffness, and the failure modes are investigated for 13 large specimens. Two recently developed reinforcement techniques, namely the externally bonded reinforcement (EBR) and externally bonded reinforcement on grooves (EBROG) will be probed for the specimens. Based on the results, prestressing the CFRP sheets attached via the EBROG technique considerably enhances the ultimate load, stiffness and ductility of the RC beam in flexure. Besides, it tends to the failure mechanism to the desirable mode of concrete face separation and spreads the cracks along the beam.