Decarbonising concrete

It’s not common knowledge that the carbon footprint of concrete is relatively low compared to other construction materials. 

However, the high amount of concrete that is used in many buildings means that it often makes up a large percentage of the total carbon emitted during construction projects. 

The UK concrete industry takes this issue seriously and is a global leader in working and investing to reduce greenhouse gas emissions wherever it can. For over a decade, it has been working towards a clear strategy to reduce its environmental impact.

In fact, since 1990 the ‘embodied carbon’ of concrete – that is to say all CO2 emitted throughout its production – has been reduced by 30 per cent.  

Similarly, UK producers of cement, a critical component of concrete, have achieved an impressive 51 per cent reduction in carbon dioxide emissions compared to 1990 levels. And while cement produces an average seven per cent of carbon emissions worldwide, in the UK this figure is less than 1.5 per cent and as a whole is decarbonising faster than the UK economy.

This huge reduction has been achieved through innovation and investment in efficient plant, switching from fossil fuels and actively researching net zero fuel mixes and by using low-carbon cement substitutes that are by-products from other industries.  

For example, adding Ground Granulated Blast-furnace Slag (GGBS) or fly ash – waste materials from the iron and electricity industries – to a concrete mix can help to reduce the carbon of a reinforced concrete flat slab by 35 per cent.

Further reductions are possible in the future through greater use of alternative and carbon-neutral biomass fuels, increased use of lower-carbon cements, and lowering indirect CO2 emissions – for example by using greener energy sources.