Seismic performance and residual displacements of reinforced concrete walls detailed with iron-based shape memory alloys

The current seismic design philosophy of reinforced concrete (RC) walls typically requires large inelastic strains and damage to accumulate in a plastic hinge region, which can result in post-event residual building displacements. Often, the residual displacements will be in such excess that the building is required to be demolished.

This costly but expected performance level (i.e., no collapse, life safe) is currently under scrutiny and instead a serviceable structure with limited damage is warranted by the building owners and engineers in the event of a large earthquake. To achieve these targets, engineers will have to implement better structural technologies.

Shape memory alloys (SMAs) have the capability to recover displacements upon removal of stress and dissipate energy through hysteretic damping.

This project investigates the efficacy of iron-based SMA bars as a substitute material for typical steel in the boundary regions of RC walls to reduce residual displacements and improve the seismic performance.

This interdisciplinary research will be carried out at the Universite catholique de Louvain, Belgium, under the supervision of Professor Joao Almeida in the Institute of Mechanics, Materials and Civil Engineering.

An extensive experimental program is proposed, which subjects large-scale RC wall specimens detailed with iron-based SMA bars to quasi-static reverse cyclic in-plane loading.

The experimental results will be used to validate state-of-the-art finite element models to undertake an extensive parametric study.

Recommendations will be provided on limiting the residual displacement of RC wall buildings, which is aligned with the next generation of Eurocode 8 guidelines.

The outcomes of this proposed research have the potential to achieve a more robust building stock internationally, increase community resilience, and promote research and technology development for natural disaster impact reduction measures.