Bridges are a significant investment and can span roads, railways or rivers, making maintenance of the steel structure costly in both time and money. For this reason, a high performance and proven corrosion protection coating is often required and specified. Metal sprayed coatings are commonly applied by flame spray or arc spray methods onto both new and existing bridge structures.
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As bridge steelwork (e.g. girders, bridge beams) is very large, metal spraying is an ideal anti-corrosion solution. There is no limit to the size of job and work can be completed on-site without the need to dismantle existing structures.
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Around the world, thermal sprayed zinc (TSZ), thermal sprayed aluminium (TSA) or thermal spray zinc/aluminium (TSZA) coatings are commonly specified and applied to give a life to first maintenance of the coating in excess of 20 years. The choice of material often depends on the environmental conditions expected for the bridge structure or sometimes local familiarity with a given material.
Image Provided Courtesy of LUMEN.
The flame and arc spray process has been used to protect bridges from the elements and road salts for decades, minimising maintenance and increasing the life of the road and rail network.
Thermal spray coatings are not only applied to structural steel bridges, they have also been applied onto concrete bridges to give corrosion protection to the reinforcing bars within the concrete structure. This is a common repair method used to extend the life of a bridge suffering from rebar corrosion. This process has been used to protect bridges for over 100 years.
1947 - Bridge Beams Zinc Sprayed with the MK16 Flame Spray System (superseded model)
