Development and study of deck joints in prefabricated concrete bulb-tee bridge girders: Experimental evaluation

Abstract

This paper presents a new bridge deck slab flange-to-flange connection system for precast Deck Bulb Tee (DBT) girders. In prefabricated bridge system made of DBT girders, the concrete deck slab is cast with the prestressed girder in a controlled environment at the fabrication facility and then shipped to the bridge site. This system requires that the individual prefabricated girders to be connected through their flanges in order to make it continuous for transverse live load distribution among girders. Two types of moment-transferring connection and two types of intermittent-bolted connection, besides one moment-transferring connection provided by lateral restraints to girder rotation, were developed. Five actual-size bridge panels were fabricated and then tested up-to-collapse to qualify these joints for use in acceleration bridge construction. The effect of the detailing of the moment-transferred connection along with the level of the fixity of the connecting steel plates of intermittent-bolted connection were examined. The developed joint was considered successful if the experimental wheel load satisfied the requirements specified in North American Bridge Codes. It was concluded that the type and detailing of the deck slab joint affected the ultimate load carrying capacity of the developed connections. The successful connection systems can be used by bridge engineers in order to design bulb-tee girder system to accelerate bridge construction.