Circular Shear Pocket Connection for Full-Depth Precast Concrete Deck Construction

Abstract

Full-depth precast concrete deck systems have several advantages compared with cast-in-place concrete deck systems in bridge construction, such as improved construction quality and safety, reduced construction duration and traffic disruption, and less dependence on weather and site conditions. Existing full-depth precast concrete deck systems use either shear pockets or open troughs to connect deck panels to supporting girders via shear connectors to achieve composite sections. These connections often complicate panel and girder fabrication and erection due to their tight tolerances, which reduces the attractiveness of precast systems. This paper presents the design and testing of a circular shear pocket connection with a single shear connector for simplified production and accelerated construction. The shear pocket will be formed using a stay-in-place large-diameter round steel hollow structural section (HSS) to provide adequate tolerance around the shear connector. A single large-diameter high strength threaded rod will be used as a shear connector at 1.2 m (4 ft) spacing in the longitudinal direction. A 100 mm (4 in.) diameter grouting hole at the center of each covered shear pocket will be used to allow filling of the shear pockets and haunch area while minimizing deck surface penetrations. Experimental investigation (push-off testing) and nonlinear finite element analysis (FEA) will be performed to validate the performance of the developed connection when different round HSS diameters and thicknesses were used. Analysis and testing results indicated that the capacity of the new connection could be predicted using the current AASHTO LRFD interface shear provisions. The implementation of the proposed connection to the construction of the Belden–Laurel Bridge, Nebraska is presented.