What is Weathering Steel
Weathering steel is a high strength, low alloy steel that was originally developed by United States Steel in the 1930s to resist corrosion and abrasion in their ore wagons. It was given the trade name Cor-ten, and was first used in construction in 1964. Since then the use of weathering steel has spread worldwide and is a popular choice for the use in Pioneer steel truss bridges.
In suitable environments, weathering steel forms a protective rust “patina” that inhibits further corrosion. The corrosion rate is so low that bridges fabricated from unpainted weathering steel can achieve a 100 year design life with only nominal maintenance.
Benefits of Weathering Steel
• Lower up-front costs: A weathering steel bridge generally costs about 10% to 15% less than a painted bridge.
• Low maintenance: Weathering steel is ideal for bridges and other structures where access is difficult or dangerous, and where future disruption needs to be minimized. Inspection and cleaning should be the only maintenance required to ensure the structure continues to perform well.
• Project life cost benefits: Nominal maintenance needs of weathering steel structures significantly reduce the costs of maintenance operations and the potential indirect costs of traffic delays.
• Construction Speed: With the elimination of painting in our shop and touch up painting in the field – construction is streamlined.
• Curbside appeal: The attractive appearance of mature weathering steel often blends in with the environment. Its appearance changes and improves with age.
• Environmental benefits: Use of weathering steel eliminates the need for VOC laden paints.
Limitations on use
Weathering Steel Bridges are suitable for use in most locations. However, there are certain environments that can lead to durability problems. Weathering steel should not be used in salt-water environments or over brackish water. Also, de-icing salts should not be used on weathering steel bridges and it not recommended for use in continuous wet/damp conditions.