In a UK first, calcined clay concrete – which replaces some cement with pulverised baked clay from, for instance, damaged bricks – has been used in an apartment building going up in North London.
Contractor Midgard used it to build a permanent suspended slab in a rented apartment building at Brent Cross Town, a 180-acre mixed-use scheme being delivered by developer Related Argent in partnership with Barnet Council.
The 200-unit building is scheduled to open in 2028.
In this case, 30% of the cement in the concrete mix was replaced with calcined clay, resulting in a 10% embodied carbon saving compared with equivalent concrete mixes previously used at the development.
Approved since 2019, but …
Capital Concrete provided the concrete made with calcined clay from LKAB Minerals, which now produces it from damaged waste bricks.
Capital Concrete notes that because abundant global clay deposits far exceed the demand for cement and traditional cement replacement alternatives, using it could cut millions of tonnes of CO2 from global construction.
Bringing UK domestic clay into the mix could also create jobs, it said.
Calcined clay concrete has been approved under British Standards since 2019 but, so far, its adoption has been limited.
“This material is a practical alternative to traditional cement replacement, enabling the industry to significantly reduce carbon emissions, support job creation and the circular economy,” said Tim Hoyland, Related Argent’s environment manager.
One of Europe’s largest regeneration projects
Brent Cross Town will have up to 6,700 new homes, with a mix of affordable homes, rentals and homes for sale. The building in question is the third build-to-rent building under construction.
Billed as one of Europe’s largest regeneration projects, the neighbourhood will have a high street, squares, sports facilities, three new schools, and 3 million sq ft of office space – all set in 50 acres of open green space.
Some 1,000 people are now living in the first phase of residential buildings completed last year.
The second phase includes 1,600 new homes, including 300 co-living studios through Halcyon, 150 retirement living homes delivered by Audley Group and Senior Living Investment Partners, and around 660 student apartments by Fusion.
