from the David Ball Group to be used in the casting of the box culverts, with additional specialised joint sealants, to ensure a perfectly dry structure.: "This tunnel project was actually quite complex. We were asked to assist the engineers with the waterproofing specifications at quite an early stage in the planning process - a dialogue that influenced both the design of the precast concrete mix for the subway's box culvert sections, and the actual installation of sections on site ".
PUDLO CWP was used in the casting process primarily as a waterproofing agent, but also as additional protection against the corrosive effects of the soil, as described in BRE Digest 363 ‘Concrete and Concrete Products in Aggressive Ground’. To ensure waterproofing of the tunnel installation, the David Ball Group's hDR waterstop was used for the spigot and socket connecting joints, which were further sealed on the inner face with INSTAFLEX PU25.
David Ball Group engineers were constantly on site to assist in the successful completion of the project, just one of the facilities which the David Ball Group offers. McNicholas Construction chose to employ this service ensuring that the project was completed on time and with as little disruption as possible.
The tunnel is an underpass that extends the Lambeth Walk by linking the promenade and apartments of the St George’s Wharf development with the frontage of the MI6 building downstream of the bridge. It was opened by the Mayor of London who commented:
"This tunnel walkway will open up the river for the public on a stretch of waterway that has previously been inaccessible, thereby making a valuable contribution to the wider renaissance of the South Bank.”
The developer, St George, was awarded ‘Major Project of the Year’ at the Quality in Construction Awards for the St George Wharf development. The development was praised as a textbook example of up-to-the-minute brownfield redevelopment.
David Ball comments
The client, St George Plc, specified PUDLO concentrated waterproofing powder |