Construction materials group
Hanson's Owen Street plant in the north west England city has supplied 110,000m3 of the concrete to the project's main contractor Renaker for use in the walls, floor, foundations and columns.
Once completed in Spring 2020, Deansgate Square will consist of four glazed towers – the tallest of which will be 64 storeys high and claimed to be the tallest building in the UK outside London – providing more than 1,500 luxury apartments and leisure facilities.
Regen GGBS (ground granulated blastfurnace slag) is a cement replacement product that is being used in the project. Hanson says it enhances the durability of the concrete while adding to its sustainability credentials. The percentage of Regen used in the concrete mixes varied from 40% in the main structural elements to 70% in the foundations and raft bases, where its use is also claimed to have help minimise the production of heat, reducing the risk of thermal cracking.
“We have designed and delivered a range of different concretes to overcome the engineering challenges of the project,” said Hanson Concrete technical services manager Terry Balmer. “These include high performance concretes providing strength in excess of 100N/mm2 in the lower columns; watertight derivates in the basement and bespoke designs containing 70% Regen GGBS in the foundations and raft bases.”
All of the concretes were also designed to be able to be pumped more than 300 linear metres across the site and, for the walls, up to 204 metres vertically.
