Hanson into final stages of Deansgate Square contract

One hundred and ten thousand cubic metres of specialist concrete supplied for UK’s tallest building outside London

HANSON are entering into the final stages of their contract to supply specialist concrete to Renaker for their Deansgate Square development in Manchester. The company has supplied 110,000 cubic metres for use in the walls, floor, foundations and columns, from its Owen Street plant in the city.

Once completed in Spring 2020, Deansgate Square will consist of four glazed towers – the tallest of which will be 64 storeys high and the tallest building in the UK outside London – providing more than 1,500 luxury apartments and leisure facilities.

Hanson have designed and delivered a range of different concretes to overcome the engineering challenges of the project. These include high-performance concretes providing strength in excess of 100N per square millimetre in the lower columns, watertight derivates in the basement and bespoke designs containing up to 70% Regen ggbs (ground granulated blast-furnace slag) in the foundations and raft bases.

All of the concretes were also designed to be able to be pumped more than 300m across the site and, for the walls, up to 204m vertically.

Regen ggbs is a cement replacement product that enhances the durability of the concrete whilst adding to its sustainability credentials. As a by-product, using it to replace one tonne of Portland cement reduces the embodied CO2 of the concrete by around 850kg.

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 also helped minimize the production of heat, reducing the risk of thermal cracking.

Terry Balmer, technical services manager at Hanson Concrete, said: ‘We have a proven track record in delivering challenging, specialist concretes for Renaker on other high-rise builds across Greater Manchester, so we were the go-to choice for the Deansgate Square project.’

‘Our technical and customer service has again proved a real asset and we are an integral part of the supply chain.’