Enhancing the behavior of reinforced concrete box girders under Two-point Loading: Numerical and experimental investigations

Reinforced Concrete Box Girders: RCBGs are considered in concrete bridges as significant members and they have been closely accepted as bridge systems due to their structural efficiency: economical construction, serviceability, high stability and aesthetic requirements. The aim of the current research is determining the best way to enhance the behavior of RCBGs, which includes the outcomes of practical and numerical programs of 15 samples tested under bending. The use of ferrocement laminate on the tensile side or in the form of a U-shape, the number of meshes, as well as their type (welded or expanded), and the use of composite materials: Carbon Fiber Reinforced Polymer and Glass Fiber Reinforced Polymer (CFRP and GFRP) were all considered. For composite materials, the strengthening was applied at the tensile side only and wrapping the composite material around the web like a U-shape along the total beam's length or as strips with different sizes and spacing. The results indicated that wrapping GFRP and CFRP sheets like a U-shape along the total beam's length gave the same ultimate loads and it represents the highest load of the tested beams. It increased by -78 % than the control beam. The numerical model gave good results in comparison with the test results. The difference between them does not increase -13 %.