Sika have cast iron solution for Coalport Bridge

High strength epoxy resin adhesive mortar and specialist coatings from Sika Limited were recently used in the strengthening work carried out on the cast iron Coalport Bridge.

High strength epoxy resin adhesive mortar and specialist coatings from Sika Limited were recently used in the strengthening work carried out on the cast iron Coalport Bridge.

Coalport Bridge as it stands today, was constructed in 1818 on the site of the original wooden structure that was opened in 1780, to carry the Brossley to Coalport road over the River Severn.

The bridge, which is both a listed building and a Scheduled Ancient Monument, had been repaired many times during its history.

Despite this, it had recently been subject to a weight restriction that permitted only one vehicle of up to two tonnes to be on the bridge at any one time.

In practise, this restriction was difficult to enforce.

Shropshire County Council and Borough of Telford and Wrekin, joint owners of the bridge, worked closely with English Heritage on the project.

Dew Construction was appointed to undertake strengthening of the bridge.

After detailed structural analysis by consultants Gifford and Partners, steel plate bonding was the only viable solution identified.

Dew construction chose SikaDur 31 to bond the plates to the cast iron structure.

Sika has a long and successful track record in both steel and carbon fibre plating technology.

SikaDur 31 is a thixotropic, high strength two component epoxy resin adhesive mortar, allowing easy and versatile applications throughout the construction industry.

Both components are different colours to ensure visual confirmation of thorough mixing.

It has an excellent bond to both cast iron and steel, and for most substrates found in construction such as concrete, brickwork, stone, timber and epoxy etc.

It hardens without shrinkage, has high abrasion resistance, and has excellent adhesion to most substrates.

Once cured, it is approved for contact with potable water.

SikaDur 31 can also be applied as a thin levelling or scraping coat, using trowel or float, to improve the physical and aesthetic properties of concrete surfaces.

It is easy to apply, with excellent non-sag properties for both vertical and overhead work.

To protect the bridge from further attack by the elements, the complete structure was coated using specialist coatings from Sika.

Icosit EG1 two part epoxy, high build intermediate coating was applied, followed by Icosit EG4 polyurethane finishing coat.

This coating system, which is also suitable for both steel and galvanised substrates, gives excellent protection against UV, chemical, impact and abrasion attack.

With work now complete, the load capacity of the bridge has been increased to a vehicle weight limit of three tonne, running in convoy, a restriction that is much easier to enforce.

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