Performance-Based Retrofitting of Aging RC Frames Using Innovative Knee-Braced Buckling-Restrained Braces for Enhanced Seismic Resilience

¹ Department of Civil Engineering, The University of Ottawa, Ottawa, Canada, zalsadoo2@uottawa.ca
² Department of Civil and Environmental, Engineering, University of Sharjah, Sharjah, United Arab Emirates, U20105784@sharjah.ac.ae
³ Research Institute of Sciences and Engineering, University of Sharjah, Sharjah, United Arab Emirates, ahabib@sharjah.ac.ae

^* Corresponding author: zalsadoo2@uottawa.ca

Published online: 19 December 2025

Abstract

The performance of reinforced concrete (RC) structures is a critical area of research, given the increasing need for resilient infrastructure in seismically active regions. Deficient RC frames, commonly found in aging buildings, exhibit limited ductility and energy dissipation capacity, rendering them vulnerable to seismic events. Currently, the literature lacks a study regarding the performance of knee-braced buckling-restrained braces (KBRBs) as a strengthening technique for deficient RC frames. Unlike traditional bracing systems, KBRBs offer enhanced energy dissipation and deformation capacity, eliminating the drawbacks associated with brace buckling. The motivation for this study stems from the need to develop innovative retrofit strategies that can enhance the seismic resilience of deficient reinforced-concrete frames while overcoming their inherent shortcomings. This study examines the seismic behavior of deficient reinforced-concrete frames strengthened with knee-braced, buckling-restrained brace systems using numerical analysis. By evaluating the energy dissipation and displacement demand of the strengthened frames, the study seeks to provide insights into the efficacy of KBRBs as a retrofitting solution. The significance of this research lies in tackling a key gap in retrofit strategies for vulnerable reinforced-concrete structures and introducing a promising approach for improving the seismic performance of deficient frames. The findings from this study will contribute to the development of performance-based design guidelines, enabling engineers to select effective retrofitting strategies that safeguard infrastructure in earthquake-prone regions.