Modélisation numérique des éléments structuraux linéaires en béton armé renforcés par des matériaux composites

Abstract

This thesis explores the use of Near Surface Mounted (NSM) Fiber-Reinforced Polymer (FRP) strips/rods to enhance the flexural strength of reinforced concrete (RC) beams. A nonlinear Finite Element Analysis (FEA) model was developed to simulate the behavior of FRP strengthened RC beams, successfully predicting experimental outcomes. Validation of bond behavior was conducted using pull-out tests from existing literature. Parametric studies were subsequently performed using the FEA model to investigate the influence of various reinforcement parameters on beam flexural performance, including bond length, number of FRP bars, concrete strength, FRP type, reinforcement ratio, and reinforcement method. Results indicated a significant enhancement in both yield and ultimate strengths, with ultimate strengths improving by up to 126% with CFRP strengthening. However, a notable reduction in ductility was observed due to debonding of CFRP strips in the strengthened beams. To mitigate this issue, the study explored more efficient strengthening techniques, focusing on optimizing the effective bond length, reinforcement ratio, and positioning of NSM bars.