Building materials supplier CEMEX is providing more than 50,000 tonnes of sprayed concrete to construction company Dragados on the capacity upgrade at Bank Underground Station in London.
Bank is one of the largest underground railway complexes on the UK capital’s underground network and is used by 300,000 passengers on a normal day. The two key objectives of the Bank Station Capacity Upgrade project are to increase capacity at the station and minimise journey times. More than 1200m of new tunnels have already been built, including three new escalator barrels.
CEMEX was contracted to provide high quality primary lining spray concrete for use in the construction of shafts, tunnels and cross passages, with four 100 tonne silos on site for storage.
The company says this job has presented particular challenges because of its location in a very busy area of London, while the station itself is remaining operational throughout construction.
Deliveries must be booked in advance and precisely timed, following pre-agreed routes through the City of London. However, there are still many pedestrians, cyclists and other vulnerable road users using the area at all times, which present a considerable risk that must be closely managed.
CEMEX worked closely with Dragados to design a site layout which enabled regular delivery of dry silo materials while minimising disruption to the traffic or pedestrians.
The project requires strategic management and coordination by CEMEX’s plant, silo, supply chain and booking teams to ensure product is produced and delivered safely and to schedule.
CEMEX says that the mix supplied is also extremely complicated, consisting of eight separate constituents which when combined give ultra-high strength of +60N/mm2, consistence of 600mm flow and a workability retention of two hours. This mix has been used on several high-profile London projects over the last seven years including the Northern Line Extension and Thames Tideway.
Michael May, sales manager for CEMEX Mortars Europe, commented: “Supplying the Bank station development has presented considerable challenges, particularly around access, but we are very proud of the dedication of our team to ensuring the specific mix of concrete was produced and safely delivered to meet the customer’s requirements.”
CEMEX manufactures the product at a dedicated spray concrete plant from where it is transported into central London. Supply is expected to continue until November 2022.
