Walton New Bridge, Warrington
Walton New Bridge, Warrington was built in 1938 to carry the A56 over the Bridgewater canal.
Both the abutments and wingwalls needed repairs due to delamination of the concrete and the spalling of the concrete cover.
The reason for the spalling was the lack of cover to reinforcement and the high permeability of the existing concrete. These factors resulted in both carbonation and chloride attack of the reinforcement.
The areas of delaminated concrete were broken out to behind reinforcement by the contractor. Large areas of breakout were repaired using Five Star Repair Concrete, a self compacting, flowable micro concrete. The smaller areas were repaired with webercem HB40 after first priming the reinforcement with webercem keycoat.
Deck repairs were undertaken with webercem pyrapatch, a fast setting repair material, allowing quick installation of the waterproofing membrane.
Following the successful completion of the repairs the surface of the abutments and wingwalls received applications of webertec guard MCI, a migrating corrosion inhibitor which protects the reinforcement against further corrosion.
In order to enhance the areas of low cover and to further protect against carbonation and chloride ingress, webercem fairing coat levelling mortar and webercote smooth anti-carbonation coating were applied to the repaired structural elements. The webercem concrete repair System holds an Agrément approved certificate.