APPLICATION OF DUPLEX STAINLESS STEEL FOR WELDED BRIDGE CONSTRUCTION IN AGGRESSIVE ENVIRONMENT

Maintenance costs are a significant item in life cycle of steel bridges, becoming of paramount importance in aggressive environments. The use of duplex stainless steels for bridge decks would be a major step forward in providing durable, low maintenance structures, exploiting both their corrosion resistance and high mechanical properties, capable of meeting in full the required structural safety performances. A research project partially funded by the EU research programme RFCS (Research Fund for Coal and Steel, Bridgeplex contract RFS-CR-04040) is developing technical information on the use of duplex stainless steel in welded bridge construction via mechanical testing and numerical analyses, so as to provide indications suitable to form the basis for an upgrade of Eurocode 3 [1] and to allow a reliable Life Cycle Cost analysis for this kind of structures so as to address the best material choice for the future bridges. The project is still in progress but first results are available. This paper gives an overview of the project and summarizes results obtained, deeper detailed in other papers presented at the International Conference Duplex 2007 ([5] and [6]). In particular the paper is concerned with: · overview of critical details in a welded bridge deck and relevant data available in literature also on austenitic and austeno-ferritic steels; and · economical evaluations considering maintenance aspects and fabrication costs showing the advantages of the application of duplex stainless steel to defined bridge typologies