GFRP reinforcement in RC structures in seismic zones

The application of glass fiber-reinforced polymer (GFRP) bars as reinforcement to concrete structures in seismic zones remains restricted by current standards, including ACI 440.11–22, and IBC 2024 due to concerns regarding the lack of ductility and energy dissipation associated with GFRP reinforcement. This paper explores strategies to overcome these limitations, focusing on the design of GFRP-reinforced concrete (GFRP-RC) structures in seismic design categories (SDCs) B and C, which correspond to regions with low to moderate seismic activity. Two approaches are proposed: hybrid reinforcement design, combining GFRP and steel reinforcement, and resistance-based design, using GFRP reinforcement exclusively. Hybrid reinforcement leverages the established principles of ACI 318–19 to ensure controlled failure mechanisms and effective energy dissipation. Conversely, resistance-based design emphasizes preventing brittle failure by ensuring sufficient resistance in structures with low ductility demands. The study highlights the potential of these approaches to enhance the durability and sustainability of structures in aggressive environments or when alternative concrete constituents that may accelerate steel corrosion are used. The paper discusses specific provisions of beam-column frames in seismic design categories B (SDC B) and C (SDC C). By introducing criteria for the use of GFRP reinforcement to concrete structures in seismic design, this research addresses a critical gap in current standards and supports the broader adoption of GFRP in structural engineering. These approaches have been recently adopted by the Saudi Building Code (SBC).