Experimental and numerical investigation of flexural behaviour of concrete beams reinforced with GFRP bars

Abstract

To solve the issue of corrosion, the use of glass fibre reinforced polymer (GFRP) bars in reinforced concrete (RC) has emerged as a feasible option for conventional steel bar RC. Given that GFRP RC beams have different mechanical properties and behaviours than steel counterparts, a thorough investigation of the load–deflection behaviour, failure modes, and overall performance of GFRP RC beams via experimental, analytical, and numerical studies is required. Therefore, this study encompasses the experimental, analytical, and numerical investigation of GFRP RC beams. Total of 9 beams are experimentally investigated, three (3) reinforced with steel bars (10 mm dia) while six (6) reinforced with GFRP bars (10 mm and 16 mm dia). Experimental results reveal that GFRP RC beams exhibit lower load carrying capacity and more deflection than their steel equivalents, respectively. GFRP RC beams have a 32.4 % lower ultimate load and a 16 % higher ultimate deflection than steel RC beams for the same reinforcing ratio. Steel RC beams failed under tension control, whereas GFRP RC beams failed under compression control. Analytical models, primarily based on effective flexural stiffness, are used to predict the load–deflection behaviour of GFRP RC beams. Nonlinear numerical modelling of GFRP RC beams is carried out using ATENA 2D. The load–deflection responses obtained from analytical and numerical studies are compared with experimental results and found to be in good agreement. After the validation of numerical models, the behaviour of GFRP RC beams has been investigated using a thorough parametric research, which looked at the impact of concrete compressive strength, longitudinal reinforcement ratio, GFRP bar elasticity modulus, and shear span to depth ratio.