Seismic behavior evaluation of reinforced concrete joints reinforced with super elastic shape memory alloy reinforcements

Shape Memory Alloys (SMAs) using in civil engineering is one of the favorable research issues in recent decades. Many researchers have carried out intensive activities to utilize innovative devices and smart materials. Among the smart materials, SMAs due to physical and mechanical features are an eligible candidate for use in structural engineering applications. SMAs positive contribution to energy dissipation, self-adaptation, re-centering, and healing of the seismic behavior of structures have been emphasized by several researchers. In this study, the seismic behavior of three height-type RC buildings using SMA reinforcement is investigated. For this purpose, SMA reinforcement as the longitudinal bar is utilized at connection joints in structures with different stories (4, 6, and 8) which can be categorized as low, mid, and high-rise buildings. For each building SMA bar was used in four reinforcement arrangements; the full steel bar type, SMA bar at the beam-column connection region and steel bar at other regions type, SMA bar at column-foundation connection region and steel bar at other regions type, and SMA bar at beam-column and column-foundation connection regions and steel bar at other regions type. The nonlinear dynamic time history analysis method was performed to investigate the maximum story displacement, inter-story drift, base shear demand, residual displacement demand, nonlinear displacement at the roof level, and other seismic behavior criteria for each building. The obtained results show the application of SMA bars with increasing of the stories is more significant. Additionally, different results were obtained depending on the using of SMA reinforcement in buildings. It was concluded that the use of SMA in beam-column connection joints is more effective than its use in column-foundation connection joints.