Effect of Steel Confinement on Behavior of Reinforced Concrete Frame

The strength and ductility of concrete are improved under multi-axial compressive stress due to confinement effect. Some effective parameters for concrete confinement are longitudinal and transverse steel reinforcement. Some stress-strain relations for confined concrete with steel reinforcement have been proposed by different researchers. In this paper, various stress strain models with considering the steel confinement effect are reviewed briefly and used for simulating the lateral behavior of on an experimental reinforced concrete frame. Envelope curves, tension damage, yielding patterns, ductility ratio and energy absorption of the frames are discussed. Results from the finite element analysis compared with experimental findings show that in the case of lateral load and displacement, the analytical models which were presented by Fafitis et al. and Muguruma et al. had more compatibility with experimental results and the difference is less than 10%. Energy absorption of the model which was proposed by Khaje Samani & Attard had the most compatibility with experimental results and difference is about 1%.