Additional Concrete Cover & Waterproofing to Pre-cast, Pre-stressed Bridge Beams
Background
Starting in 2011, the Riverside Energy from Waste (EFW) Facility at Belvedere will process 585,000 tonnes of residual waste annually to generate electricity for 66,000 homes in London.
To minimise congestion on the roads, the waste will be transported by barge along the River Thames to a newly constructed wharf. To ensure the design life of the new link bridge is achieved, consultants, Royal Haskoning, required enhancement of the 35mm cover to the pre-stressing strands in the pre-cast beams which support the main deck over the river.
The Solution
Royal Haskoning specified 2mm of Cementitious Coating 851, which is completely impermeable to water under 10 bar hydrostatic pressure (100 metre head of water) and gives the equivalent of 100mm of good quality concrete cover. In order to blend in, the colour of the 851 was matched to that of the parent concrete. A total of 91 beams were coated by Concrete Repairs Ltd at Anchor Bay Wharf in Erith where they were stored, following manufacture by Tarmac at their Taunton works, prior to being transported to site by barge.