Finite Element Analysis of Flexural Behavior of GFRP and Steel Reinforced Fly Ash–Polypropylene Fiber Concrete Beams Using ANSYS

Steel reinforcement in concrete structures is highly susceptible to corrosion which leads to significantly durability concerns. To address this challenge, this study numerically investigates the flexural performance of concrete beams reinforced with glass fiber-reinforced polymer (GFRP) rebars as a replacement to steel. In this study, a finite element (FE) model was developed in ANSYS mechanical APDL to simulate the behavior of M-30 grade concrete beams with two mix designs by including 20% fly ash and 1% polypropylene fibers (FA+PP) and nominal concrete. Beams dimensions of 1500 x 230 x 300 mm were modeled with steel or GFRP reinforcement. Nonlinear material constructive models were used to capture cracking, crushing and rebar-concrete interaction. The accuracy of FE model in simulating load deflection performance and failure modes was validated using experimental results. Numerical results demonstrated that steel-reinforced beams made with FA+PP produced the highest resistance against loading force alongside minimal beam movement yet FA+PP beams using GFRP bars displayed an average strength level together with continuous flexural deflection. The study concludes that ANSYS simulation is an effective tool for evaluating the structural feasibility of GFRP rebars in reinforced concrete, supporting their potential as a corrosion resistant alternative to steel.