Behavior of concrete beams reinforced with hybrid steel and FRP composites

Abstract

This paper presents a nonlinear finite element model to investigate the behavior of hybrid Fiber Reinforced Polymers and steel reinforcement. Different types of Fiber Reinforced Polymers; CFRP and GFRP; were used along with steel rebars in the studied concrete beams. The study was conducted using the nonlinear finite element program “ANSYS”. Nonlinear material models for the components of the concrete beam were used in the three dimensional finite element models. The outcomes got from finite element analysis were confirmed against experimental results. A broad parametric study was conducted to explore the effect of replacing steel reinforcement by different types of FRP bars. The study showed that the contribution of steel rebars to FRP rebars in concrete beams improved beam ductility and eliminated the unfavorable brittle failure of the concrete beam. In addition, it is better to use steel rebars as top reinforcement in concrete beams with hybrid reinforcement. In hybrid GFRP/steel reinforced concrete beams, a significant reduction in stiffness and a noticeable increase in the beams' deflection after the initiation of first crack and yielding of steel reinforcement were observed. On the other hand, in hybrid CFRP/steel reinforced concrete beams showed a better performance during cracking initiation and propagation.