Salmon River Highway Bridge

The first steel-free deck-slab in Canada was cast on the Salmon River Bridge, part of the Trans Canada 104 Highway near Kemptown, Nova Scotia. Construction of the bridge, which consists of two, 31-m spans, includes a steel-free deck over one span and a conventional steel reinforced deck over the other. Internal arching in the slabs helps transfer the loads to the girders. Although the steel-free side cost six percent more than the steel-reinforced side, the overall design tends to be less expensive than conventional decks. This is due to less maintenance because of corrosion.

The deck contains no rebar. Instead, longitudinal beams or girders support it. The load is transferred from the deck to the supporting girders in the same way that an arch transfers loads to supporting columns. Although steel straps are applied to to tie the girders together, because they are not embedded in the concrete, they can be easily monitored and inexpensively replaced.

Also, with no steel inside the concrete, no unnecessary weight is added, meaning thinner deck designs. The steel straps are welded to the top flanges of the girders thereby resisting any lateral movement. The Salmon River steel-free bridge deck has withstood a number of Canadian winters, and it appears to be defying the conventional approach to building steel-reinforced bridge decks.