EXPERIMENTAL AND NUMERICAL SIMULATION OF GFRP CONFINED CYLINDRICAL CONCRETE UNDER COMPRESSION

Abstract

Fiber Reinforced Polymer (FRP) wrap stands as one of the most popular methods for retrofitting deteriorated reinforced concrete structural elements. Among the available options, Glass Fiber Reinforced Polymer (GFRP) presents itself as a cost-effective alternative, although with fewer technical advantages. While GFRP wrapping is commonly applied to columns, the extent of its confinement effect on altering the mechanical properties of concrete remains unclear. To address this gap, an experimental and numerical analysis was conducted. Concrete cylinder specimens wrapped with GFRP layers were axially tested under compression until failure. The resulting stress-strain relationship was used to validate numerical simulations carried out using numerical simulation with finite elements method. The experimental findings suggest that concrete confinement using only a low number of GFRP wraps may not be effective in providing adequate lateral restraint for concrete under compression. GFRP for concrete confinement clearly transforms the material from being brittle to becoming ductile, resulting in a deformation capacity that can be up to 2-5 times greater. A numerical model of the confined concrete cylinder with GFRP specimens could show the confinement effect to increase the ultimate stress and strain. In addition, the numerical model could investigate the failure pattern with good agreement with the experimental results.