Advanced seismic retrofitting techniques for existing reinforced concrete buildings: a comprehensive review

Abstract

This comprehensive review synthesizes the current knowledge on advanced seismic retrofitting techniques for existing reinforced concrete (RC) buildings, addressing the critical need to upgrade vulnerable infrastructure in seismically active regions. This study aims to evaluate seven major retrofitting approaches, providing evidence-based guidance for practitioners and researchers. A systematic review was conducted encompassing experimental studies, numerical analyses, case studies and real-world examples. This review examines fiber-reinforced polymer (FRP) wrapping, steel jacketing, concrete jacketing, base isolation energy dissipation devices, shear walls and bracing systems. Performance metrics, applicability criteria, design parameters and economic considerations were developed through experimental validation and real-world implementation. FRP wrapping demonstrates exceptional versatility for member-level strengthening, achieving up to 98% improvement in collapse margins by providing additional strength to the structure. Base isolation provides superior performance with 50%–85% drift reduction and 4–5 × safety improvements, although at a higher initial cost. Energy dissipation devices offer targeted supplemental damping (30%–60% drift reduction) with replaceability advantages. Steel and concrete jacketing remain effective for strength enhancement (30%–80% and 20%–45%, respectively), whereas shear walls and bracing systems provide additional system-level stiffness. The technique selection depends critically on the building characteristics, deficiency types, occupancy constraints and economic factors. Recent studies have included FRP anchoring systems for access-constrained joints, box-section metallic dampers with stable hysteresis and hybrid approaches. This review provides a comprehensive synthesis of performance metrics, design parameters, codal provisions and economic considerations across all major retrofitting techniques. The novel contributions of this study include: integrated comparative analysis across seven retrofitting approaches covering advances from 2015 to 2024; evidence-based applicability matrices for technique selection across diverse building characteristics; identification of critical code gaps and standardization needs; comparative cost–benefit analysis integrating lifecycle considerations; and expanded future research directions on sustainability, resilience-based design and long-term durability, which are insufficiently addressed in prior reviews.