High Quality Thermal Spray Coatings for Steel Bridges
Given the sheer size of most bridge steelwork, metal spraying offers a practical and effective solution to help protect bridges from corrosion.
Long Term Protection with Thermal Spray Coatings
Across the world, thermal sprayed zinc (TSZ), aluminium (TSA), and zinc/aluminium (TSZA) coatings are widely used to protect bridge steel. These coatings can provide more than 20 years of protection before any significant maintenance is required. The material selected usually depends on the environment the bridge will face – whether that’s exposure to saltwater, heavy rainfall, industrial pollution or just general wear – or in some cases, local preferences for one material over another.
Here in the UK, organisations such as National Highways (formerly the Highways Agency) and Network Rail include thermal spray coatings in their specifications. These coatings are commonly applied to all types of bridges – road, rail, pedestrian and waterways. One of the most iconic examples is the Forth Road Bridge, opened in 1964 and, at the time, the longest suspension bridge outside the USA at 2,512 metres. Metallisation Ltd was proud to supply the zinc spray for that project. Since then, we’ve helped coat hundreds of bridges worldwide.
Concrete Bridge Protection
As well as the protection of steelwork, thermal spray coatings have also been applied onto concrete to give corrosion protection to the reinforcing bars within the concrete structure. This is commonly a repair method used to extend the life of a bridge suffering from rebar corrosion.
Example Applications
Footbridges
Though smaller in scale, footbridges face the same corrosion risks as larger structures. Whether it’s for new installations or refurbishments, our thermal spray coatings keep footbridges looking good and structurally sound for years.
Road and Rail Bridges
Heavily used and exposed to tough conditions, road and rail bridges demand reliable corrosion protection. From salt spray and exhaust fumes to vibration and weathering, these structures face constant stress.
How Does the Coating Process Work?
We use metal and thermal spray technology.
First, we prepare the steel surface, usually by blasting it with grit to remove any old coatings, rust, or dirt. This gives the metal coating something to grip onto.
Next, we spray thermal spray coatings directly onto the steel bridge structure. This is commonly achieved by using flame spray or arc spray methods.
As the molten metal hits the surface, it cools and hardens, forming a tough and highly adhesive layer.
The sprayed metal layer acts as a shield, protecting the bridge steel underneath from moisture, salts and other corrosive elements. Sometimes, a sealer is applied on top to further extend the life of the coating.
Let’s Talk About Your Next Project
If you’re ready to find out how our solutions could support your next bridge project, we’d love to hear from you. Speak to our team today for expert advice, equipment options, or a technical chat about your requirements.
The case studies shown below are just a small summary of the number and type of bridge structures that have been sprayed over the years.
