Standard rating for embodied emissions could help concrete decarbonise by 2050, report says

Construction experts have called for a standardised rating system to assess the amount of carbon embedded in different concrete mixtures.

A new report, published by the Green Construction Board and Institute of Civil Engineers (ICE), set out three ways to decarbonise concrete by 2050.

Concrete accounts for 8% of carbon emissions globally, with the production of the necessary cement requiring high temperatures and involving chemical reactions which produce greenhouse gases.

Experts from across the industry – including the Concrete Centre, Mott MacDonald and materials giant Cemex – suggested the adoption of an industry-wide rating system, similar to the one used to disclose the energy efficiency of homes.

They also suggested reductions in the cement content of mixtures – for instance by using limestone and calcined clays – and the adoption of design approach requiring less material, such as the use of voids, coffers, non-structural fill and smaller spans between columns.

An update to technical standards to reflect the priorities of carbon reduction is also advocated in the report, entitled Low Carbon Concrete Routemap.

As well as making recommendation, the experts set out three routes to decarbonisation by 2050, the most optimistic of which would see the industry absorb more greenhouse gases than it emits by the 2040s. A more modest model sees emissions cut in half by 2035.

Such advances would mean major cost savings, according to the report, ranging from £2.5bn to £10.5bn by 2050, depending on how quickly the industry decarbonises.

>>> READ MORE: What are we going to do about concrete?

The speed of this process may depend on the development of carbon sequestration – techniques of locking CO2 into concrete and of capturing carbon arising from cement production.

While these techniques are not yet commercially viable, the report authors called for large-scale industry and government support for research.

Report co-author Andrew Mullholland said the next 10 to 15 years were critical and said the decarbonisation drive would require “motivation and substantial effort from across the industry”.

A new UK Concrete Decarbonisation Taskforce, convened by the ICE, is to update the report each year and monitor progress across the industry.