Moment Redistribution and Ductility of Continuous Self-Compacting Concrete Beams Reinforced with Hybrid and Hybridized GFRP-Steel Systems

The integration of Fiber Reinforced Polymer (FRP) and hybrid reinforcement systems in continuous concrete members offers a promising solution to corrosion issues and structural efficiency. This study experimentally investigates the structural performance, ductility, and moment redistribution capacity of six two-span continuous SCC beams. The specimens, with a compressive strength of 45 MPa and dimensions of 200×250×2800 mm, were reinforced with different configurations: conventional steel (NSC-S), pure GFRP (NSC-F), hybrid steel and GFRP (NSC-SF), and innovative hybridized bars (H-series) with varying reinforcement ratios. The results revealed that the hybridized-reinforced beams outperformed other configurations in terms of the spread of plasticity and moment redistribution. While the GFRP-reinforced and certain hybridized specimens exhibited reduced ductility compared to the steel-reinforced beam, the specimen NSC-H achieved a moment redistribution degree of 19.86%, which is 29% higher than the reference steel beam (15.35%). Analysis of plastic hinge characteristics showed that hybrid bars promote a wider distribution of inelasticity, with the ratio reaching 2.04, compared to 1.90 for steel. Furthermore, the NSC-SF system demonstrated a balance between load-bearing capacity and ductility, retaining 93% of the curvature ductility of the steel beam. The findings conclude that hybridized reinforcement systems offer an alternative for continuous structures, ensuring both structural safety and substantial moment redistribution.