Ultra-high performance concrete (UHPC) is in a relatively new class of cementitious materials. These concretes demonstrate good durability properties, high compressive strength, and usable tensile resistance. The high compressive and useable tensile resistance can lead to smaller and more efficient precast cross sections. Smaller precast cross sections result in lower member self-weights, which in turn can allow for easier transportation, longer span or shallower depth superstructures, and reduced foundation requirements. The durability properties of UHPC specifically lend themselves toward use in the most environmentally stressed portions of our nation?s bridge inventory, namely the decks. The advanced properties of UHPC allow for the development of new structural systems. This research project focuses on the development of a precast full-depth bridge deck component that can be used both in new construction as well as in the redecking of existing bridges. A two-way ribbed slab system shows promise when combined with the properties of UHPC. As compared to standard cast-in-place concrete bridge decks, this system can be lighter in weight, develop composite action from built-in pockets, utilize the durability properties of UHPC while decreasing the volume of required material, and efficiently use the UHPC tensile and compressive resistances.
The key project objective is to assist stakeholders by developing a new means for the accelerated redecking of bridge structures with an extremely durable and robust system. This is to be accomplished by developing a practical optimized ultra-high performance concrete (UHPC) bridge deck element, and then working with appropriate stakeholders to begin deploying the technology.
The New York State Department of Transportation (NYSDOT) is playing a leading role in using UHPC to create splice connections between deck level components.
During the summer of 2009, NYSDOT constructed two bridges using this type of connection detail. The first bridge, located in Lyons, used UHPC to create the deck-level connection between adjacent deck-bulb-Tee prestressed girders. This 6-inch-wide connection across which the reinforcement is spliced is filled with field-cast UHPC. The second bridge used UHPC to connect conventional precast deck panels. Located near Oneonta, the deck panels were placed on the steel stringers then the extending rebar was spliced via a 6-inch-wide UHPC connection. [Source: Research Impacts: Better-Faster-Cheaper (2010)]