Flexural behavior of hybrid fiber-reinforced polymer/concrete beam/slab bridge component

This paper presents an experimental and analytical investigation on the flexural behavior of a hybrid fiber-reinforced polymer (FRP)/concrete beam/slab bridge component. The beam element consists of a carbon/epoxy cylindrical shell filled with concrete where the FRP shell serves the dual purpose of formwork and reinforcement. A conventional reinforced concrete slab connects to the FRP/concrete girder through steel dowels anchored in the girder concrete core. The composite beam/slab system was experimentally investigated through a full-scale four-point bending flexural test. Section analysis procedures and approximate formulas for the flexural response of FRP/concrete beam/slab units were developed and correlated with experimental results. The shear connection efficiency was additionally evaluated through a push-out test and correlated with codified recommendations. The importance of stress concentrations on holes drilled for connection purposes on generally anisotropic shells was assessed. The overall investigation showed that the presented hybrid FRP/concrete concept is a viable option for beam-and-slab bridges.