Flexural behavior of GFRP rebars and steel rebars with polypropylene fibers and fly ash-based concrete

Alternative materials are required since steel reinforcement in concrete constructions is prone to rust, which creates durability issues. This study investigates the feasibility of replacing steel reinforcement in concrete applications with glass fiber-reinforced polymer (GFRP) rebars. The experimental work used M30 grade concrete with two mix designs: fiber-reinforced concrete (FA+PP), which replaces cement with 20% fly ash, and nominal concrete (NC), which uses 1% polypropylene fiber. Both mixes met M30 standards,FA+PP showed higher strength. Four steel or GFRP reinforced concrete beams sized as 1500 mm × 230 mm×300 mm underwent flexural loading tests. The period for NC beam curing amounted to 28 days but FA+PP beams received 56 days of treatment before testing. The experimental 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. Structural specimens reinforced using steel demonstrated superior results than specimens made of GFRP and NC materials during load-bearing examination. GFRP rebars demonstrate value as steel reinforcement replacement because they provide corrosion protection and structural strength according to this research finding.