COMPARATIVE REVIEW OF FLEXURAL BEHAVIOUR AND SERVICEABILITY OF GFRP AND STEEL REINFORCED CONCRETE BEAMS

Abstract

Glass Fiber Reinforced Polymer (GFRP) bars have emerged as a practical alternative to conventional steel reinforcement for reinforced concrete members, particularly in structures exposed to corrosive environments. Their high tensile strength, low self-weight, and resistance to corrosion have encouraged researchers to investigate their structural performance under flexural loading. However, the relatively low modulus of elasticity of GFRP influences stiffness, crack development, and deflection, making serviceability an important aspect of design. This review critically examines recent research on the flexural behaviour and serviceability performance of GFRP-reinforced concrete beams. Published experimental, analytical, and numerical investigations are assessed to compare the structural response of GFRP- and steel-reinforced members. The discussion focuses on load-carrying capacity, load-deflection response, first cracking load, crack width, reinforcement ratio, bond behaviour, failure mechanisms, durability, and current design recommendations. The review also evaluates the influence of material characteristics on structural performance and highlights the strengths and limitations reported in previous investigations. The findings indicate that GFRP-reinforced beams are capable of achieving satisfactory flexural strength while providing excellent resistance to corrosion and reduced maintenance requirements. Nevertheless, larger deflections and wider cracks are generally observed because of the lower stiffness of GFRP bars, requiring greater attention to serviceability during design. Existing design standards provide a useful framework for practical applications, although further refinement is required for long-term behaviour, crack prediction, and bond performance. The review concludes by identifying research priorities that may contribute to the wider and more efficient application of GFRP reinforcement in reinforced concrete structures.