Corrosion protection of steel bridges

The use of steel for modern bridges has grown significantly over the last 20 years. Engineers and specifiers have recognised the benefits that steel offers as a construction material, which combined with imaginative designs has resulted in some striking bridges that have not escaped the public’s attention.

Modern bridges currently have a design life requirement of 120 years, and the performance of the protective system is a critical factor. Furthermore, reductions in the number of repainting cycles have become significant in the evaluation of whole life costs. Weathering steel, and enclosure systems, offer very low maintenance alternatives.

There has been a widely held view that most steel bridges require frequent attention to maintain the original protective coating system. In reality, coating lifetimes to first major maintenance have progressively increased from 12 and 15 years to 20 and 25 years.

From the continued developments in coating technology, modern high performance coating systems may be expected to achieve lives to first major maintenance in excess of 30 years on thoughtfully designed steel bridges. In addition, the use of weathering steel, and enclosure systems, offer very low maintenance alternatives.