Old Bridges Give Clues to Steel Deck Performance

Whenever steel deck bridges are discussed, the question invariably arises: How well do the steel decks perform over the years? More specifically: How safe is a steel deck against corrosion? How good must the wearing surface be to protect it adequately? Is there a danger that the steel deck, with the top surface normally not accessible, will deteriorate under the surfacing? The answers to these questions are provided by actual experiences with steel deck bridges. The oldest of the new("orthotropic plate") type steel bridge decks in Europe are, by now, 15 years old. Some steel deck structures of older types are more than twice that age, and considerable experience with them has been accumulated. In this country, steel deck bridges of the new kind are still in the design or pre-construction stage. However, there are many "battledeck floor" type bridge structures in service, built in the 1930s. Two notable examples are the Harlem River Bridge and the Bronx-Kill Bridge in New York City built in 1936 and recently resurfaced. The writer had an opportunity, on behalf of American Iron and Steel Institute, to investigate the conditions of these steel decks after 27 years of service.