New type of cement from ceramic waste

To date, the researchers have worked with brick, sanitary ware (washbasins and toilets) and porcelain stoneware waste, resulting in an end product that is stronger than the mortars used today.

"It is an entirely new material. Its main characteristic is that it does not contain portland cement, which turns it into a more sustainable material. It is only composed of ceramic waste, a chemical activator and water," explains Mª Victoria Borrachero, researcher at the Concrete Science and Technology Institute (ICITECH, in Spanish) of the Universitat Politècnica de València.

Crushed bricks

The first studies were carried out using red clay brick waste and sodium hydroxide or sodium silicate solutions as activator substances.

"In this particular case, the process is very simple: first, we grind bricks, then, they are milled and mixed with the activator solution. We immediately mix them with the aggregate and then the mortar is ready to be put into molds and undergo a high-temperature hardening process," explains Mª Victoria Borrachero.

The researchers are now focused on the study of the performances of the products created from the sanitary ware and stoneware waste. Moreover, they are analyzing new activator substances to make an end product that is even more sustainable .

"We have already done tests with rice husk ash and the results are very positive. Its use would give us a more sustainable and cheaper end product, because it would be composed, almost entirely, of reusable waste," says Mª Victoria Borrachero.