3D FE Analysis of RC Beams Externally Strengthened with SRG/SRP Systems

Abstract

Abstract:The purpose of this study is to evaluate, through a nonlinear Finite Element (FE) analysis, the structural behavior of Reinforced Concrete (RC) beams externally strengthened by using Steel Reinforced Grout (SRG) and Steel Reinforced Polymer (SRP) systems. The parameters taken into account were the external strengthening configuration, with or without U-wrap end anchorages, as well as the strengthening materials. The numerical simulations were carried out by using a three-dimensional (3D) FE model. The linear and nonlinear behavior of all materials was modeled by appropriate constitutive laws and the connection between concrete substrate and external reinforcing layer was simulated by means of cohesive surfaces with appropriate bond-slip laws. In order to overcome convergence difficulties, to simulate the quasi-static response of the strengthened RC beams, a dynamic approach was adopted. The numerical results in terms of load-displacement curves, failure modes, and load and strain values at critical stages were validated against some experimental data. As a result, the proposed 3D FE model can be used to predict the structural behavior up to ultimate stage of similar strengthened beams without carrying out experimental tests.

A FEM-based model to study the behavior of SRG-strengthened R/C beams

“…Previous studies [35] and software guides [39] generally suggest the use of isotropic two-dimensional plane stress elements to model externally applied fabric jackets (e.g. FRP).…”

“…In general, finite element analysis of externally applied composite reinforcement, combined with inorganic binders, for retrofitting of structural elements (beams or columns) is very limited in the literature. To the best of authors' knowledge, the only FEM-based investigation of SRG-retrofitted R/C beams is the one conducted by Bencardino and Condello (2016) [35] who simulated five flexure-deficient beams using the general-purpose finite element software Abaqus. The corresponding experimental results were utilized to calibrate the numerical simulation and assess its efficiency.…”