Ultimate Behavior of Deck-to-Girder Composite Connection Details Using UHPC
Zachary B. Haber, Benjamin A. Graybeal, Brian Nakashoji
Abstract
Prefabricated bridge deck panels are a popular option for new construction and bridge rehabilitation. Further, ultra-high-performance concrete (UHPC) has become a common option for closure pours between adjacent prefabricated deck elements and between deck elements and the supporting girders. This study presents experimental research on the ultimate behavior of two new and simplified deck-to-girder composite connections that use UHPC and innovative detailing. The proposed systems were developed to simplify fabrication procedures and enhance on-site constructability. The two connections investigated in this study rely on short shear connectors on the supporting girders and either rebar dowels protruding from the underside of the deck panels or shear pockets that pass through the deck. These concepts were evaluated using a combination of small-scale direct shear tests and large-scale, double shear push-off tests. Experimental variables included pocket geometry, shear stud configuration, rebar dowel configuration, and dowel length. Results indicate that these novel connection details are ductile and have the potential to meet the existing strength limit state requirements in the AASHTO Bridge Design Specification (BDS) for horizontal shear.