Hybrid Fiber-Reinforced Polymer Girders Topped with Segmental Precast Concrete Slabs for Accelerated Bridge Construction

The behavior of composite girders made of hybrid fiber-reinforced polymer (HFRP) I-girders, topped with precast ultra-high-performance, fiber-reinforced concrete (UHPFRC) slabs is presented in this paper. HFRP I-girders were manufactured under the pultrusion process in which unidirectional carbon fibers and bidirectional fiberglass fabric or continuous strand mat were used. Four large-scale composite girders were tested under four-point flexural loading. In the first composite girder, the HFRP I-girder was topped with a full-length precast UHPFRC slab. Twelve precast UHPFRC segments were used in each slab of the other three composite girders. Either epoxy or mortar connections were used to connect the precast UHPFRC segments. The test results showed that the flexural stiffness of the composite girder with the epoxy-connected segmental precast slabs was similar to that of the full-length precast composite girder. The mortar-connected girder exhibited more ductile behavior than the epoxy-connected girder. All the composite girders exhibited significant improvements in strength and stiffness compared with the HFRP I-girder without the UHPFRC slab. The HFRP–UHPFRC composite girders were shown to provide a promising and sustainable solution for accelerated bridge construction.