Microplane-Based Nonlinear Finite Element Analysis of Fiber-Reinforced Polymer-Strengthened Reinforced Concrete Columns

Abstract

This paper presents the results of nonlinear finite element (FE) analysis of fiber-reinforced polymer (FRP)-strengthened reinforced concrete (RC) columns under different combinations of axial compression (P) and bending (M) loads. Three-dimensional FE models of RC columns were analyzed for different eccentricity (e) to depth (h) ratios as: a) axial loading (e/h = 0); b) uniaxial eccentric loading (e/h = 0.15 and 0.63); and c) pure bending (e/h = ∞). Three different strengthening schemes-namely, 1) near-surface mounting (NSM); 2) external bonding (EB); and 3) hybrid strengthening. were considered. The load-displacement curves, P-M interaction diagram, and failure modes from FE analysis and experiments compared quite well. The validated FE modeling approach was used for performing parametric investigation to evaluate the influence of: 1) concrete strength; 2) carbon FRP (CFRP) laminate ratio in NSM strengthening; 3) CFRP fabric ratio in EB technique; and 4) CFRP ratios in hybrid strengthening.