Scientists at the University of Tokyo used waste concrete and trapped carbon dioxide to combine them into a new building material. The result is concrete from calcium carbonate – it is strong and practically not harmful to the environment.
The researchers noted that the new sustainable type of concrete will reduce air emissions from the construction industry. Calcium carbonate concrete is made from waste concrete and carbon dioxide from air or industrial exhaust gases. It can be used as a reliable building material, especially in places where natural resources are limited.
The material will solve the problem of emissions from concrete production: about 7% of the world’s carbon dioxide emissions come from the production and use of cement, the main component of concrete. Moreover, a significant part of this 7% is associated with the use of calcium, which is usually obtained by burning limestone.
“We use calcium from concrete, which usually goes to waste,â€� the scientists noted. – We combine it with carbon dioxide from industrial exhaust or air. And we do it at much lower temperatures.”
They added that calcium carbonate is a very stable material, which makes it strong building materials. But calcium carbonate concrete cannot yet completely replace conventional concrete. It is still possible to make blocks of a few centimeters long from it for small houses.
“Progress in this area is very important, but so far we have a lot of problems,â€� added the scientists. “In addition to increasing the tensile strengths and dimensions of calcium carbonate concrete, we need to reduce the energy consumption of the entire process. But we hope that in the coming decades, carbon-neutral concrete based on calcium carbonate will become the main type of concrete.â€�