Comparative analysis of seismic behavior of RC buildings with Shape Memory Alloy rebar in regular, torsional irregularity and extreme torsional irregularity cases

SMAs (Shape Memory Alloys) have been implemented about a decade in design of the concrete buildings and improving their behavior. Among the major advantages of reinforced concrete structures with SMA one could refer to their super-elasticity property and the reversibility of inelastic displacements in the structure. In this article the seismic behavior of RC buildings with SMAs in regular, torsional irregularity and extreme torsional irregularity cases for three height types of building is investigated. For this purpose the effects of SMA as longitudinal reinforcement in structures with different number of stories (3, 6 and 9) which represented the Low, Mid and High-Rise buildings are examined. For each building, three reinforcement arrangements including the case of full Steel, the case of SMA at the plastic region of the beams and Steel reinforcement in other regions and also the case of SMA rebar over the entire length of the beams are taken into consideration. In all of the above cases, the Steel rebar is used in columns for economic purposes. In continuation, nonlinear dynamic time history analysis method was performed where the parameters of the maximum drift, residual drift, amplification factor, residual amplification factor, and base shear were investigated for each case of the mentioned buildings. The obtained results indicate that application of SMA in irregular buildings mitigates the devastative effects of irregularity, including reduction in the base shear and drift in buildings.