Structural repair contractor Balvac has been strengthening the Clifton Bridge in Nottingham, which carries the A52 over the River Trent. This has been effected by installation of external post-tensioning within the box sections of the bridge in a contract worth over £700,000. According to Balvac it is the first completed project of its type in the UK.
The structure has an overall length of 240m and is formed of two hollow section post-tensioned reinforced concrete end spans with a central deck supported on half joints.
Balvac was the principal contractor and had to remove two redundant gas mains as well as install the anchorage and deviator blocks, the post- tensioning and the tightly controlled stressing of the system. Work was carried out within the restricted space of the box sections and the bridge remained fully trafficked throughout.
Balvac says 42km of tendon was stressed and the use of the VSL system allowed the tendon ends to remain available for stress monitoring and re-application at the 12 month maintenance inspection to restore any losses.
Balfour Beatty company Balvac is also working on the strengthening of Kingston bridge in Glasgow. And it is carrying out the £4M design and construct repair contract for London's historic Lancaster Place Vaults with Gifford & Partners as designer and City of Westminster and engineer Rendel Palmer & Tritton also on the team.
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