Nonlinear finite element modeling and experimental investigation of SFRC beams strengthened with GFRP laminate under static loading

Various strengthening techniques were adopted to strengthen beams with weaker cross-section. In recent years, Fibre Reinforced Concrete Composites (FRCC) and Fibre Reinforced Polymers (FRP) have led to many potential applications in structural engineering. This study through experimental tests, primarily investigated the performances of Steel Fibre Reinforced Concrete (SFRC) beams bonded externally at the soffit with Glass Fibre Reinforced Polymer (GFRP) laminates inorder to examine their flexural behaviour under static loading conditions. The experimental results were compared in lieu with numerical predictions computed through nonlinear finite element software ANSYS. For the experimental investigation, six concrete beams were externally bonded at beam soffit with GFRP laminates and one concrete beam was treated as control specimen without any external GFRP laminate bonding. The beams were designed considering the under-reinforced condition of the limit state design philosophy. The beams were micro-reinforced with hook-end steel fibres in different fibre volume fractions (Vf) and strengthened at the soffit by GFRP laminates of thicknesses (t) 3 mm and 5 mm. Flexural loading was applied on the beams adopting two-point loading. The loading was applied in increments until the failure of the beams. A 3-D model in ANSYS software was developed and a nonlinear FEA was performed. The load–deflection curves obtained from this nonlinear FEA were plotted and compared with experimental curves. The results of the 3D nonlinear finite element model developed based on the experimentally validated SFRC beam specimens proved to establish a reasonably agreeable predictions.