Seismic Behaviour of SMA-Reinforced Slender Concrete Shear Walls

Superelastic Shape Memory Alloys (SE-SMA) have provided a viable novel alternative to conventional steel reinforcement for the construction of earthquake-resilient structures. The capacity of SE-SMA to recover from high strains upon unloading provides the mechanism required to develop self-centering smart structures. Shear walls are routinely used seismic force resisting systems in concrete construction, which makes them qualified candidates for the application of SE-SMA longitudinal reinforcement. The integration of SE-SMA into a hybrid-reinforced flexural system is expected to rectify inelastic lateral displacements and economize the cost of post-disaster repair. A large-scale slender superelastic Nitinol-reinforced concrete shear wall was tested numerically and experimentally, along with a control specimen, under quasi-static load reversals to assess seismic performance. The results of the SE-SMA wall demonstrated efficient dissipation of seismic energy to achieve high drift recovery and easily repairable damage, suggesting a low probability of demolition and substantial savings over the lifetime of the structure.