Flexural Behavior of Hybrid FRP-Ultra High Performance Fiber Reinforced Concrete Composite Beams

摘要

This paper presents the development of a new composite beam consisting of a hybridCFRP/GFRP I-beam and precast Ultra-High Performance Fiber Reinforced Concrete (UHPFRC)slab. Hybrid FRP (HFRP) provides the advantage of high corrosion resistance while UHPFRChas high strength and durability. The combination of these two materials is expected to benefitstructures subjected to severe environmental conditions and wherever there is a need foraccelerated bridge construction. Three full-scale composite beams with varying UHPFRC slabwidth were tested under four point flexural loading. Bolt shear connectors with/without epoxybonding were used in the tested beams. The bolt shear connectors and epoxy were used to resistthe horizontal shear flow at the interface between the HFRP I-beam and the UHPFRC slab. Thecomposite action between the HFRP I-beam and UHPFRC slab was investigated. The test resultsshowed that all the composite beams exhibited significant improvements in stiffness and strengthproperties, above those of simple HFRP I-beam without UHPFRC slab. A fiber model wasdeveloped to predict the strength and stiffness of the tested beams and the model accuracy wasverified. A fairly good agreement between the experimental and analytical results was found.High tensile strength of the CFRP in the HFRP tensile flange can be effectively utilized anddelamination failure of the HFRP compressive flange can be prevented by addition of theUHPFRC slab on the top flange of the HFRP I-beam. The study revealed that HFRP-UHPFRCbeams are efficient and can provide a very competitive, cost-effective and sustainable solution tobridge structures.