Modeling of CFRP strengthened RCC beam using the nonlinear finite element method

Computational modeling of fracture in reinforced cement concrete (RCC) beam considering various phenomena has been a challenging task over the years. This paper presents a crack modeling methodology in three dimensions for carbon fiber reinforced polymer (CFRP) strengthened RCC beam by performing a three dimensional nonlinear finite element analysis of the beam subjected to four point loading. The concrete is modeled as inelastic material. Various concrete failure parameters such as shear transfer coefficients, uniaxial tensile and compressive strengths, biaxial compressive and crushing strengths and stiffness reduction in cracked concrete in tensile region are considered. In numerical studies an unstrengthened beam with and without hanger bars are considered for the analysis and results are compared with experimental results. In the next case, a CFRP strengthened RCC beam is considered for analysis. A parametric study is performed considering different length of CFRP used for flexural strengthening of beams, modeling CFRP as Isotropic and orthotropic and varying the area of steel reinforcement in tension region. The study indicates that the proposed method is able to accurately predict the behavior, crack patterns and load carrying capacity. The results are comparable with the experimental results available in the literature