Evaluating the Seismic Risk of FRP Retrofitting Schemes for Corroded RC Frame Structures Based on Benefit-Cost Assessment

Abstract

Fiber-reinforced polymer (FRP) has been widely used to retrofit existing structures to improve their seismic performance. A reinforced concrete frame structure is designed as a case study structure to study the impact of FRP retrofitting on the seismic risk of corroded structures. Finite element models are established using the OpenSEES finite element platform for intact structures, corroded structures, and FRP-retrofitted corroded structures by considering two corrosion damage degrees and four FRP retrofitting schemes. Based on the results of seismic fragility and risk analysis, combined with the economic loss models, the retrofitting schemes are evaluated using the benefit-cost ratio (BCR) as the indicator. Three factors, including the economic development level of the building site, remaining service life, and changes in discount rates, are considered in the economic loss assessment. The impact of these factors on the benefits of structural retrofitting is analyzed through three cases. The results indicate that greater economic benefits are generated by retrofitting structures in economically developed regions with higher corrosion damage degree. Meanwhile, it is found that ignoring the remaining service life of the structure may lead to an overestimation of the retrofitting benefits. Finally, considering different discount rates, it is found that higher discount rates lead to lower BCR values. The conclusions of this study will benefit engineers in formulating reasonable FRP seismic retrofitting schemes for existing structures.

Keywords

benefit-cost assessment / economic loss / FRP retrofitting / reinforcement steel corrosion / seismic risk

RIGHTS & PERMISSIONS

2025 Tianjin University and John Wiley & Sons Australia, Ltd.