Crossrail C610 – Heavyweight concrete pumping
The February 2017 edition of the Concrete Society’s magazine Concrete, has an article about placing heavyweight concrete to form part of the Crossrail track slab in central London. The joint venture contractor installing the track on this project is ATC jv (Alstom, TSO and Costain), the concrete is supplied by London Concrete and the concrete pumping is being carried out by Camfaud.
Heavyweight concrete was considered the best option for this section of track bed in order to minimise the noise and vibration generated by the Elizabeth line when it is in service, especially in noise sensitive areas with recording studios above. The heavyweight concrete used contains MagnaDense, a natural aggregate which is approximately twice as dense as normal aggregate.
MagnaDense from LKAB Minerals is formed of black ferrimagnetic natural iron oxide (magnetite) and is mined in Kiruna and Malmberget in northern Sweden. As the article notes, Camfaud Concrete Pumps chose a Putzmeister BSA2110HP static pump as the main stationary concrete pump, with another high-pressure pump being used as a backup and also to clean the lines using a water wash-out system.
The concrete has been pumped through 1100m of pipeline, during which time there was approximately 40 tonnes of material contained in the line. The same edition of Concrete magazine has an article about the new Medway valley crossing, built by BAM Nuttall to give access to the new 1000 home, Peters Village.