Subventions et des contributions :

Subvention ou bourse octroyée s'appliquant à plus d'un exercice financier. (2017-2018 à 2022-2023)

Force-based and performance-based seismic design approaches specify target maximum drifts as indicators of performance level and damage. Post-earthquake reconnaissance observations have further identified the additional importance of residual drift as a measure to quantify structural performance and the operational state of a structure. The residual drift, therefore, determines whether a structure can be serviceable, requires repair, or must be demolished. The overarching goal of this research is to develop resilient concrete structural systems, reinforced or retrofitted with smart materials, to control permanent damage that arises during response to seismic excitations leading to structures that are immediately serviceable. Shape Memory Alloys (SMAs) are one class of smart materials that have the ability to control permanent deformations. The material has the capacity to sustain large strains, levels that would induce significant permanent straining in steel reinforcement, but with the superior capability to return to its original shape after removal of stress (Superelastic (SE) SMA) or with the application of heat (Shape Memory Effect (SME)). This is the main behavioural feature that makes the material attractive in seismic applications. Other salient characteristics include strength and displacement capacities comparable to steel reinforcement, in addition to stable hysteretic response.

The focus herein is to exploit the mechanical properties of SE-SMA towards the development of resilient structures including new and old construction. Specifically, improved modelling capabilities will be developed to provide tools for performance assessment of SE-SMA reinforced concrete structures. This will be achieved through a new nonlinear hysteretic constitutive model for SE-SMA and finite element modelling procedures. Retrofitting with a novel buckling restrained brace that encompasses an SE-SMA inner core acting as a fuse will be developed for existing seismically deficient reinforced concrete frame structures. An alternative SE-SMA bridge column will be designed and tested to assess compatibility with the Canadian Highway Bridge Design Code (CHBDC) and to establish damage indicators required in performance-based design. Finally, the long-term performance of SE-SMA-reinforced concrete structures will be assessed by inducing corrosion in bridge columns followed by experimental testing to determine the lateral strength and displacement capacities, and the ability of the columns to re-center following corrosion damage.