Earthquake resilient RC walls using shape memory alloy bars and replaceable energy dissipating devices

This study presents a novel precast reinforced concrete (RC) wall system using shape memory alloy (SMA) bars and replaceable energy dissipating (ED) devices to achieve earthquake resilience (hereafter referred to as SMA-based RC wall). The major advantages of this structural system include (1) self-centering (SC) capability provided by the unbonded superelastic SMA bars used in the bottom boundary zones of the wall, (2) concentrated energy dissipation and damage in the replaceable steel angles, and (3) an earthquake resilient design that requires minimal repair even after strong earthquakes. The structural details and design considerations of the SMA-based RC wall were first introduced. Subsequently, the mechanical behavior of the SMA bars and ED angles was investigated through cyclic loading tests. The seismic performance of the SMA-based RC walls was computationally investigated using various parameters of interest in seismic applications and evaluated in terms of strength, stiffness, and SC and ED capabilities. The proposed SMA-based RC walls exhibited satisfactory and stable flag-shaped hysteretic loops with excellent SC and satisfactory ED capabilities. Compared with conventional RC walls, the proposed SMA-based RC walls provide a promising solution for high-performance structural systems required by modern resilient and sustainable civil infrastructure. (paper)