Strengthening of an existing RC building with superelastic SMAs

Abstract

Retrofit of deteriorated Reinforced Concrete (RC) structures has been widely investigated to enhance their performance and avoid the environmental impact due to demolishing and reconstruction. As conventional design concept is oriented to a predictable, ductile behavior allowing for significant inelastic deformation, implying extensive damage of structural members and leading to costly repairs after serious earthquake incidents, smart materials occupied with an inherent re-centering ability have been investigated for retrofit applications to reduce structural damage, constituting potential candidates for innovative interventions that can improve the structural resilience under seismic actions. In this work, a RC building situated in Athens, Greece is used as a case study to evaluate the potential of Shape Memory Alloys (SMAs) in structural retrofit, exploiting their property to reset inelastic deformations by unloading exhibiting the superelastic effect. Different types of SMAs are investigated to assess the effectiveness of the proposed retrofit scheme as an alternative solution to conventional steel performing pushover and non-linear dynamic time history analysis with SeismoStruct software. Results show maximum and residual displacement reduction and provide useful information on the application of SMAs as a damage-control and cost-efficient scheme in structural retrofit with the view to deal with the issue of significant residual deformation after earthquake action.