Recycled concrete is renewed with wood waste

Publicerat 2 June, 2020

By adding lignin from wood waste, researchers in Tokyo have succeeded in strengthening recycled concrete without adding new cement. The lignin even gave the concrete a higher bending strength than usual.

Lignin is the adhesive that gives plants their strength and bind them together. Among other things, it can be used as a binder in a variety of products, ranging from food, medicines and cosmetics to bioplastics.

Researchers in Tokyo have now also conducted successful tests with lignin as a binder in recycled concrete. By mixing lignin with previously used concrete and water, which are then heated under high pressure, they have created new concrete without having to add new cement. In addition, the concrete came out even harder than the original.

Reduced carbon dioxide

As cement production contributes to a high carbon dioxide emission, a reduced use is favourable for the environment.

“These discoveries can contribute to a greener and more economical construction industry, which not only reduces the amount of left overs of concrete and forest material, but also helps in addressing climate issues,” says Yuya Sakai at the University of Tokyo, according to Ny Teknik.

The researchers have high hopes that in the future it will be possible to create concrete from scratch with lignin. That it then will be possible to use le agricultural waste and mix it with sand and gravel.