Numerical Study on Moment Redistribution in Hybrid Steel-FRP Reinforced Concrete Two Span Continuous Beam
摘要
FRP (Fiber Reinforced Polymer) bars offer advantages over steel, but their linear elastic behavior leads to brittle failure, raising concerns about moment redistribution. The combinations of steel and FRP bars can be used to address the issues of using steel or FRP bars alone. Steel-FRP hybrid reinforced concrete is a relatively recent concept; as a result, it is still in the development stage. Therefore, this study investigates the effectiveness of hybrid (steel+FRP) reinforcement in increasing the moment redistribution of a two-span continuous beam. A numerical model for two-span continuous concrete beams reinforced with Basalt FRP bars (4200 mm long with a 200 mm × 270 mm cross-section) was developed using ATENA 2D and validated against experimental data. Following validation, the model was extended to investigate different hybrid reinforcement ratios in the sagging and hogging regions. Varying hybrid reinforcement in critical sections results in a remarkable moment redistribution of up to 34.7%. Furthermore, the direction of moment redistribution is found to be dependent on the stiffness of critical sections.