A new type of vaulted floor reduces concrete use and emissions

Engineers have developed a way to design concrete floors so that they use far less concrete to carry the same load – delivering huge carbon savings

Spotted: According to the United Nations Environment Programme, emissions from the construction industry accounted for 30 per cent of global emissions in 2019 – with concrete production accounting for a large chunk of that. Now, an interdisciplinary team from the universities of Bath, Cambridge, and Dundee has developed a new design approach which could significantly reduce the environmental impact of the construction industry.

The team’s project, dubbed Automating Concrete Construction (ACORN), takes an innovative approach. Instead of developing a concrete substitute, they are using structural analysis to design floors that use only a quarter of the concrete – by putting the material only where it is needed. Concrete is good at resisting compression, but is not good at resisting tension from bending, which results in the need for steel reinforcement.

ACORN places the concrete where it will have the greatest effect on compression. The result is a thin, curved floor, made using an automated adaptable mould and a robotic concrete spraying system. This is combined with bespoke software that optimises the design of the floors and controls manufacturing. As people walk across the, the force flows down the curved structure, compressing the concrete, which can bear the load without reinforcement.

The ACORN team have also designed reversible joints, to allow floors to be disassembled and reused elsewhere at the end of the building’s life – promoting a circular economy for the construction industry. According to ACORN, this approach can already deliver slabs with less than 40 per cent of the embodied carbon of traditional flat slabs, “with future research likely to lead to even more savings as processes are optimised.”

We have seen a number of recent innovations aimed at reducing delivering a more environmentally friendly concrete, including a plan to use microbes to grow cement and a bio-crete made from weeds and crayfish shells. However, these may not be ready for mass roll-out in time to avert climate catastrophe. The ACORN project, could fill the gap and allow countries to meet their COP 26 targets.