Development and study of deck joints in prefabricated concrete bulb-tee bridge girders: Conceptual design

Abstract

Speed of construction, particularly for bridge replacement and repair projects, has become a critical issue to minimize disruption of traffic and commerce. A promising system for rapid construction is a precast bridge system using decked bulb tee prestressed concrete girders. This type of bridge includes manufacturing the bridge deck precast and pretensioned with the girder in the precast plant under controlled environment. Then, the precast girders are transported to the construction site, and placed over the abutments and piers beside each other with flanges of adjacent girders field connected. Load transfer between adjacent girders is provided by longitudinal joints parallel to traffic direction. This paper presents a new bridge deck slab flange-to-flange connection system for precast Deck Bulb Tee (DBT) girders. The objectives of this study were to develop moment-transferred and intermittent-bolted connections for DBT bridge girders in view of the ultimate strength of the connection system. Two types of moment-transferring connection and two types of intermittent-bolted connection were developed. The paper presents design procedure of the developed joints based on available design equations in North American design codes for bridges and structures as well as related design equations available in the literature. The developed joint was considered successful if the theoretical resistance satisfied the requirements specified in North American Bridge Codes. Comparison between the theoretical findings and the available experimental failure loaded of actual-size bridge deck specimens simulating the developed connection justified the proposed theoretical design procedure.