How can we decarbonise concrete?
15 Jun 2021
Published in: Construction Manager, June 2021
World Environment Day on 5 June presents us all with an opportunity to evaluate our environmental footprints and the daily measures we must take as individuals, businesses and industries to decarbonise and encourage biodiversity, says Elaine Toogood.
There is currently a lot of misperception being created around the perceived ‘problems’ with cement and concrete. Understanding the current UK emissions position and the practical ways the construction industry can cut carbon, as well as the role of the UK concrete sector’s roadmap to beyond net zero is therefore becoming increasingly important.
The UK concrete and cement industry has taken considerable early action to reduce carbon emissions. Due to investment in fuel switching away from traditional fossil fuels to waste and waste-derived biomass, changes in product formulation, and energy efficiency including plant rationalisation, the industry emissions are 53% lower than 1990. This has helped the sector to decarbonise faster than the UK economy.
“Some new cements have 60% lower embodied CO2e than a benchmark based on Portland Cement.”
In addition to these structural changes to manufacturing, it is also possible to construct buildings and homes by using low carbon concretes which use less clinker, the energy intensive part of cement production.
Cementitious materials such as fly ash, GGBS (ground granulated blast-furnace slag) and limestone are available and being used to produce a range of lower carbon cements. Through design and specification there are also plenty of other ways to decarbonise a concrete structure – the key at a project level is to assess the possible options early on.
The industry is also expanding the range of low carbon concretes available. The Mineral Products Association (MPA) is currently working on a project through the BEIS-funded Industrial Energy Efficiency Accelerator programme to develop, test and demonstrate low carbon multi-component cements. Some of these new cements have 60% lower embodied CO2e than a benchmark based on CEMI (Portland Cement).
In the year of COP26, it’s critical the construction sector and government understand that concrete’s net zero journey is important. The UK concrete industry has set out an ambitious and robust roadmap to deliver beyond net zero. This strategy is not based on offsetting or offshoring production. Instead, it uses seven technologies – including decarbonised electricity and transport networks, fuel switching, greater use of low-carbon cements and concretes as well as Carbon Capture, Use or Storage (CCUS) technology for cement manufacture – to deliver net zero.
To reach net zero, significant technological, structural and behavioural changes are required by the industry, its clients and specifiers of construction materials across buildings and infrastructure – as well as investment and buy in from Government.
With a credible roadmap in place, wider society and construction will be able to benefit from net zero concrete as well as the material’s existing and essential qualities of fire protection, resilience and durability.
View a recent on-demand webinar ‘Decarbonising UK concrete'.
Written by - Elaine Toogood is head of architecture at The Concrete Centre