Propump has used 1000m3 of foamed concrete to strengthen a railway viaduct in Bermondsey as part of the £1 billion East London Line extension, dubbed the ‘rail version of the M25’ by Boris Johnson.
Appointed to deliver a new 2.4km stretch of track between Surrey Quays and Clapham Junction, contractor Birse Metro Ltd approached Propump to provide a versatile, lightweight concrete solution that would enable the viaduct to withstand the additional train line.
The new train line is being laid on a disused track and will pass over a number of existing arches on its route to London Bridge. With the new line joining from below and on a curve in the track, this would impose extra loadings onto the structure. As a result, a strong yet lightweight concrete solution was required.
The foamed concrete, supplied at a density of 1300kg/m3 was pumped into the various arches of the viaduct over fifteen separate visits at an average of 65m3 per visit. Electronic monitoring equipment was also encapsulated within the foamed concrete to record any potential movement and ensure the foamed concrete remains stable for years to come.
Reliable, strong and lightweight, foamed concrete proved to be the ideal solution, showing why it is so often specified for projects of this type. With a density that can be specified to suit the project’s exact needs, it has also been used to strengthen and stabilise the Widford Viaduct in Chelmsford and the Thameslink Borough Viaduct in London.
The East London Line Extension began in 2005 with the first phase extension of the original line at its northern and southern ends. Phase 2 is to be completed by the end of 2012 with the new, improved orbital line making it vastly easier for millions of Londoners to travel from one side of the city to another.« Foamed concrete proves crucial to bridge strengthening works – October 2011