Milestone reached at record-breaking tower

A key milestone has been reached in the contract to supply concrete to TwentyTwo, a £591 million, 278-metre tower which is set to be the tallest building in the City of London on completion next year.

Hanson is half way through its three-year contract to supply concrete to the project – formerly known as The Pinnacle – and has delivered over 52,000 cubic metres of structural concrete mixes for use in the core, columns and floor slabs.

All of the mixes contain Hanson’s Regen GGBS (ground granulated blastfurnce slag) cement replacement product, which enhances the durability of the concrete while adding to its sustainability credentials. Its use in the raft slab – which contains 68 per cent Regen – also helped minimise the production of heat, reducing the risk of thermal cracking. 

TwentyTwo, located in Bishopsgate, will offer 62 floors of flexible workspace for up to 12,000 people. The steel-framed tower has a central, supporting jump-form concrete core and perimeter concrete columns. 

Hanson is supplying a range of bespoke mixes to contractor Careys Civil Engineering from its Kings Cross, Silvertown and Victoria Deepwater plants. These include jump-form and lightweight concrete mixes as well as a complex design for 22 feature columns ranging in size from 4.5 metres to 16 metres high.

"We have pumped the lightweight concrete mixes higher than ever before," said Ian Goddard, technical production manager at Hanson Concrete. "By supplying 54 floors for the project, so far, Hanson has already exceeded the previous record in London which was 50 floors at One Canada Square, Canary Wharf."

Matt Kirsop, project manager at Careys Civil Engineering, added: "Hanson has supplied concrete mixes that have been successfully pumped up to a height of 270 metres. The mixes are highly workable allowing our operatives to efficiently place and achieve the required finish.”