Recipe for greener concrete

Concrete has a huge carbon footprint. Researchers at MIT in the USA have now developed a method to make its production more climate-friendly. The secret ingredient: baking powder.

A building site with large amounts of rubble

Despite the many advantages of concrete as a modern building material, including its high strength, low cost and ease of production, its production currently accounts for about 8 per cent of global CO2 emissions.

Recent discoveries by a team at MIT have shown that introducing new materials into existing concrete manufacturing processes could significantly reduce this carbon footprint without changing the mechanical properties of the concrete.

The key to the new process is the addition of a simple, inexpensive ingredient: sodium bicarbonate, also known as baking powder. In laboratory tests with sodium bicarbonate, the team showed that up to 15 per cent of the total carbon dioxide produced in cement manufacturing can be mineralised in these early stages - enough to significantly improve the material's global carbon footprint.

Shorter construction times

In addition, the resulting concrete hardens much faster without compromising its mechanical performance. This process allows the construction industry to be more productive: Formwork can be removed earlier, reducing the time required to complete a bridge or building.

The research is not yet complete. But MIT engineers stress that these new discoveries could mean an optimistic future for the development of carbon-neutral building materials.

Written by: as

Photos: Keystone

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