Behavior of Engineered Cementitious Composite-Repaired Superelastic-Shape Memory Alloy Reinforced Shear Walls

Shape Memory Alloys (SMAs) and High-Performance Fiber Reinforced Concretes (HPFRCs) are innovative materials that provide an opportunity to improve the post-earthquake state of reinforced concrete structures, while achieving the design objective. The combination of these two materials lead to self-centering with improved damage tolerance. In this research, previously tested, Superelastic-Shape Memory Alloy (SE-SMA) and typical-steel reinforced concrete shear walls are repaired and tested under the same simulated seismic loading. The repairing method involved the removal of the heavily damaged concrete in the plastic hinge zone, replacement of ruptured and buckled steel reinforcement, and casting of Engineered Cementitious Composite (ECC) where the previous concrete was removed. The numerical modelling and experimental testing of the repair technique highlight that the brittle behavior of concrete in tension and its deformation incompatibility with reinforcing steel bars, and yielding of steel reinforcement are suppressed by establishing a composite system that integrates the self-centering phenomenon of SE-SMA and the distinctive ductility properties of ECC.