Eco-friendly cement made from burnt clay

Researchers at SINTEF have developed an eco-friendly alternative to limestone cement using impure Norwegian clay.

The manufacture of cement has a very large carbon footprint. Huge amounts of fuel are used to heat limestone — the raw material — at 1450 degrees, producing tons of CO2. We have a seen a number of greener building solutions, such as the a building block that is carbon negative, and an eco-friendly brick, which is made from industrial waste. Now, researchers at SINTEF have developed another solution using impure clay to make a more eco-friendly material.

The burnt clay cement is made from Norwegian blue clay, which consists of a mixture of crystalline quartz and the minerals kaolin, illite and smectite, making it significantly less reactive than other clays. As a result, it produces much less CO2. As much as 50 percent of the cement mixture can be burnt clay, without jeopardizing the material’s strength. The rest of the mixture is regular limestone clay. The material, made in Norway, doesn’t require any refinement process and has the added benefit of using local materials, therefore limiting the amount of emissions created in transportation.

Clay is found all over the world – could this eco-friendly alternative be produced in other countries too?