Weathering steel bridges in the UK

Weathering steel is a high strength low alloy steel that in suitable environments forms an adherent protective rust patina, to prevent further corrosion. The corrosion rate is so low that bridges fabricated from unpainted weathering steel can achieve a 120 year design life with only nominal maintenance. Hence, a well detailed weathering steel bridge in an appropriate environment can provide an attractive, very low maintenance, economic solution in many locations. This paper highlights the benefits of weathering steel bridges, describes the limitations, and comments on both the material availability and the appearance of such bridges. It also provides advice on a range of issues including, design and detailing, fabrication and installation, inspection and maintenance, and remedial measures should corrosion rates exceed those anticipated at the design stage.