Empty Subway

Not going underground: Propump enables subway fill without road closures

Propump Engineering’s mobile foamed concrete production system provided the space saving solution necessary to reduce disruption when filling the 800m3 of gyratory subway in Southwark, London, as part of an ambitious project reforming crossings in the area.

A busy intersection between the A2 and the London Inner Ring Road, it was imperative that filling the pedestrian subway system did not result in road closures. The compact nature of Propump’s mobile production system ensured that all work could take place from the centre of the roundabout, without losing any of the strength of the concrete at a density of 1,100kg/m3.

A survey of pedestrian’s usage of the footpaths and subways to cross the Bricklayers Arms roundabout carried out in June 2012 showed that only 50-70 people a day used the subway between 7am and 7pm. A key factor, cited by TFL, was the design of underground crossings encouraging crime and anti-social behaviour. In place of the newly filled subway system, pedestrians are to be encouraged to use crossings at street level; perimeter footways will be repaved and a new crossing will be provided to the North East of the roundabout.

The base mix is delivered to the site in liquid form, Propump’s foam concrete unit requires minimum space while still supplying strengths between 0.5 Newton/mm2 and 10 Newton/mm2 making it perfect for projects such as this. Foamed concrete expands to fill a void of any shape meaning that the work can be done from one position, filling several subway tunnels at once.

In choosing Propump’s services, Gavigan Paving Limited were influenced by the company’s previous success with Ringway Jacobs. Propump also boast a large number of achievements in the industry including what is thought to be the second largest lightweight foamed concrete project in the UK at Gerrard’s Cross Tunnel.

Work was completed in March 2013 and pedestrians can now be assured a safer experience when crossing the Bricklayers Arms roundabout, in part thanks to the expertise and high quality foam concrete of Propump Engineering.

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