Historical steel slag waste and low-energy alkali fusion will sequester carbon to bring existing low carbon cement to net zero emissions
A £7.6m project to develop and mass produce a concrete with net zero embodied carbon is under way in the UK.
The three-year ‘Mevocrete’ project will see academics at Teesside University work with Middlesbrough-based company Material Evolution to develop and optimise its low carbon geopolymer cement technology for production at scale.
Material Evolution’s existing low carbon cement emits up to 85% less embodied CO2 than traditional Portland Cement, and now researchers aim to further boost its performance to net zero emissions by using local steel slag waste that can sequester carbon.
According to David Hughes, associate dean and co-lead of the project, the plan is to tap into large volumes of historic waste from the region’s steel production.
‘The Teesworks site is one of Europe's largest industrial development zones and is covered in steel slag from the old steelworks,’ Hughes says. ‘There are millions of metric tonnes there, just to start with, never mind all the other key areas within the UK with similar slag deposits.’
The Mevocrete project is a key element of Teesside University’s £13.1m Net Zero Industry Innovation Centre, part of Tees Valley Combined Authority’s regional innovation strategy.
Material Evolution’s patented technology avoids the emissions associated with traditional cement, which relies on energy-intensive calcination to activate and bind materials, producing CO2 as a byproduct. Instead, waste materials are activated through a solid state chemical reaction using ‘ultra-low energy alkali-fusion’ that doesn't require heat or release CO2.
This project has the potential to have a major impact in reducing greenhouse gas (GHG) emissions
According to Hughes, the Mevocrete project is the ‘the next stage’ of the product’s evolution, integrating waste materials, including steel slag, that can sequester CO2 to further cut emissions and ultimately create a net zero cement.
‘It's about the ability to sequester carbon in the cement, either during the alkali fusion stage, during the curing stage, or in use, so for example, a bench could be carbonating as you sit on it,’ said Hughes.
Researchers from the School of Computing, Engineering & Digital Technologies will analyse steel slag and its chemical composition and measure how efficient it is at sequestering carbon.
Also within the scope of research are plans to examine the entire supply chain, from the feedstock to the end user, and create an independently tested and verified net zero emissions product by the end of the project, in October 2025. Furthermore, there are plans to build a full scale on-site facility for cement production, using waste steel slag from Teesworks.
Sina Rezaei Gomari, Mevocrete project principal investigator at Teesside University, said: ‘For the UK to meet its net zero targets it is imperative that new ways to decarbonise the construction industry are found, and this project has the potential to have a major impact in reducing greenhouse gas (GHG) emissions.’
Several other organisations worldwide are working to cut the emissions profile of concrete, for example a project incorporating waste plastic into the material mix. Swiss researchers recently made a bridge from reused concrete blocks with comparable embodied CO2 to glulam.
The global concrete market is worth around £500 billion annually, yet it is one of the world’s single biggest polluters, accounting for up to 8% of GHGs according to research by the think tank Chatham House.