Concrete Prisms and Cylinders Wrapped by FRP Loaded in Compression with Small Eccentricities

Abstract

Fiber-reinforced polymer (FRP) wrapping has been extensively studied for strengthening reinforced concrete columns. However, few studies were found on the behavior under small eccentric loads, a frequent situation in real-world applications. In this paper an experimental, numerical, and theoretical study on the influence of small eccentricity of loading in FRP-confined prisms and cylinders is shown. Thirty-six short concrete specimens of different cross sections were tested under concentric and eccentric loads. Unwrapped specimens as well as specimens wrapped by one or two layers of FRP were tested. All specimens showed increases in axial strength and ultimate strain due to wrapping with FRP. The lateral displacement was also measured for all specimens until failure. A simple finite-element model was used to predict the axial strength and axial and lateral displacement. Simplified theoretical procedures were also used to generate axial load–bending moment interaction diagrams. The accuracy of both numerical and theoretical procedures to predict the experimental behavior depended significantly of the confinement model used.