Concrete/Steel Hybrid Decks

Concrete/steel hybrid decks consist of a combination of the open grid deck and the full depth precast deck panel systems. There are two common forms of this decking system: partially filled grid decks and Exodermic™ decks. The partially filled grid decks involve casting concrete for the lower section of the deck and including the open grid. Later, the rest of the deck will be poured on-site. The Exodermic™ decks involve the same process as the partially filled grid decks except that a majority of the concrete is placed above the steel grid. These systems act as composite members.

Exodermic Deck. Photo credit D.S. Brown Company

Concrete/steel hybrid deck panels are used as an alternative to cast-in-place concrete decks. They provide a driving surface for traffic.

To connect the separate panels to one another, bolted or welded connections are used. Since the deck is very similar to a full depth precast concrete depth, welded stud shear connectors are used to connect the deck panels to the steel framing.

With the partially filled grid decks, the deck can be placed without on-site formwork, which is a time-consuming process in bridge construction. With the Exodermic™ deck, the benefit of not having to prepare formwork is again prevalent. This case also has the benefit of the composite action in the deck increasing the efficiency of the system. (See Exodermic Decks and Steel Bridges by the D.S. Brown Company.)

Photo Credit: Faddis