Lifetime Economic and Environmental Impacts of BRB Retrofitting in Seismically Deficient RC Buildings

Abstract Reinforced concrete (RC) frames with low ductility remain a significant concern, particularly in regions prone to moderate to high seismic activity. Their global popularity calls for robust seismic retrofitting strategies to mitigate potential economic, social, and environmental impacts. Among these strategies, buckling-restrained braces (BRBs) have emerged to be effective for enhancing seismic performance with extensive experimental and numerical studies. However, the critical influence of masonry infills on the seismic performance of BRB-retrofitted structures is often overlooked due to their brittle nature. This study investigates the efficacy of BRB retrofitting in reducing life-cycle costs and improving sustainability metrics for low-ductility RC frames. A three-story, three-bay, low-ductility RC frame was selected as the case study structure. State-of-the-art finite-element models were developed in OpenSees for infilled and non-infilled frames, with and without BRBs. The modeling explicitly incorporated masonry infills, accounting for their strength and stiffness. A cloud analysis–based approach was adopted to develop the probabilistic seismic demand models and fragility curves. A state-of-the-art methodology was subsequently used to estimate economic loss, carbon emissions, and embodied energy. These metrics were then compared across configurations, providing stakeholders and decision makers with valuable insights to support informed choices in seismic risk mitigation using retrofits and sustainable design.