Researchers at the Institute of Architecture and Urban Planning at the University of São Paulo have developed a type of concrete made with recycled materials. Sand produced with the waste from molds used for smelting metallic components replaces 70 percent of conventional sand, while slag from steel production is used instead of crushed stone.

“In addition to minimizing the use of raw materials, the reuse of these waste materials benefits industries, since these are hazardous wastes that must be disposed of in specific industrial landfills at a cost of 200 reais (100 dollars) a ton,” Javier Mazariegos Pablos, a materials engineer and one of the inventors of the process, told Tierramérica.

The new concrete has been provisionally patented and has begun to be used for the production of paving stones.