An Experimental and Numerical Investigation on the Flexural Behavior of Two-Way Slabs Reinforced by Hybrid Reinforcement Schemes

This study examines the Characteristics of flexural behavior in a two-way slab reinforced with a hybrid combination of Glass Fiber Reinforced Polymer. (GFRP) and steel reinforcement. It determines the effectiveness of hybrid reinforcement and fiber addition in enhancing the flexural resistance of two-way reinforced concrete slabs. Researchers tested twelve reinforced concrete slabs and divided them into four groups. There were two control specimens: one steel-reinforced and one glass fiber-reinforced polymer (GFRP)-reinforced, for comparison with the hybrid specimens. The remaining specimens were reinforced using a combination of steel bars and GFRP bars, The study focused on three-parameter categories: reinforcement type (steel bars, GFRP bars, and hybrid reinforcement), reinforcement ratio (ranging from 0.50% to 0.85%), and concrete mix type (plain, glass fiber-reinforced, and steel fiber-reinforced) adding a constant 1% volume fraction of glass and steel fibers to the concrete mix, with variations in the GFRP-to-steel bar ratio, bar diameter, and reinforcement configuration. The experimental results showed that using hybrid reinforcement with additional fiber strength enhanced the flexural capacity by up to 32% compared to slabs reinforced with an equal mix of steel and GFRP bars. Also, using steel fibers in the hybrid slab method boosted the load capacity by 13.3% and reduced deflection by 20.5% compared to glass fiber-reinforced slabs. Additionally, a 3D non-linear finite element analysis using ABAQUS software was conducted to predict the flexural properties of slabs reinforced with the hybrid technique. The numerical model effectively captured the slabs' failure patterns, deflection, and ultimate load compared to the experimental results.