Mechanical Performance of Novel Prefabricated Composite Girder with Top Flange of Ultra Hight Performance Concrete Waffle Deck Panel

A novel prefabricated composite girder with the top flange of an ultra-high-performance concrete (UHPC) waffle deck panel in place of a normal concrete deck panel was proposed, to resolve problems associated with the high self-weight and high probability of cracking in conventional steel-concrete composite structures. To investigate the mechanical behaviour and application of the structure in continuous bridges, a whole bridge model and mid-support region girder model of a typical three-span continuous bridge were established by finite element analysis (FEA). The mechanical behaviour of the novel composite girder under various load modes was studied, and the influence of the key design parameters for the UHPC waffle deck panel on the mechanical behaviour of the novel composite girder was analysed. In addition, the influences of the composite dowel-type shear pocket and stud-type shear pocket on the mechanical performance of the novel composite girder were compared. The maximum tensile stress at the bottom of the longitudinal ribs and the top deck of the UHPC waffle deck panel meets the tensile strength limit of reinforced UHPC under the composite action of dead loads and live loads; when the longitudinal ribs and transverse ribs are 90 mm in width, 200 mm in height, 700 mm in the space of the longitudinal ribs, 600 mm in the space of the transverse ribs, and 60 mm in the thickness of the top deck, the UHPC waffle deck panels exhibit better mechanical performance than before. The composite dowel-type shear pocket is more applicable to the novel prefabricated composite girder than the stud-type shear pocket.