Behavior of Reinforced Concrete Frames Retrofitted by Different Configurations of Concentric Steel Braces

In the past few decades, multi-story X-braced frames have frequently been used to retrofit RC buildings and have become the subject of more attention and implementation to improve the stiffness and strength of structures. In this study, a comprehensive series of inelastic analyses were undertaken to better understand the nonlinear behavior of reinforced concrete frames retrofitted with different bracing configurations subjected to cyclic lateral load. At first, finite element model of a one-story reinforced concrete frame was developed, the analyses were carried out and the system behavior was verified by comparing the results of numerical model with experimental test. Then, a two-story frame is considered and retrofitted by implementing different bracing configurations including V-bracing, Ʌ-bracing, one-story X-bracing and two-story X-bracing type and the responses of the models are investigated subjected to cyclic loads. The results indicate that the two-story X-brace has a better performance compared to other specimens and the stiffness, strength, and behavior of this system is more desirable.