A foundation slab has been poured for HS2’s new Euston station using a type of concrete that emits far less CO2 than normal construction grade concretes.
The foundation slab will support polymer silos used for future piling works at the north end of the Euston station site. Whilst the foundation is temporary, it will be in use for two years, and historically would have been constructed with a more traditional cement-based concrete.
Earth Friendly Concrete (EFC) is made from a combination of ground granulated blast furnace slag, pulverised fly ash and a high-alkaline chemical, rather than Portland cement. This helps to reduce the concrete’s embodied carbon by around 70%.
(c) HS2
John F Hunt, working for HS2’s station Construction Partner, Mace Dragados joint venture, completed the 232 m3 concrete pour in early September.
Martin Needham, John F Hunt’s Senior Project Manager, said: “We chose to use the EFC, not only for the over 70% saving in embodied carbon, but also for its excellent characteristics. It has an increased tensile strength, enabling thinner slab designs and therefore a reduction in overall volume of both concrete and reinforcement.”
In addition to the application of EFC, collaboration saw the use of 20-yard skips instead of the standard concrete thrust blocks for the temporary works design during the process to remove a retaining wall. This alone resulted in a saving of 30 tonnes of CO2. John F Hunt also used GreenD+ Hydrogenated Vegetable Oil (HVO) for all site vehicles instead of diesel, saving around 29 tonnes of CO2.
Elsewhere on the Euston site, the HS2 and MDjv team have adopted a number of measures aimed at reducing the environmental impact of construction, including the use of liquefied petroleum gas generators as a direct replacement for diesel generators, and using a new piling method that will provide heating for buildings above.
It will be a shame having to dig that all up when the redesign goes thru. Save £50 billion on HS2, or bankrupt the country.