Alternative cement with low carbon footprint developed

Researchers at the Martin Luther University Halle-Wittenberg (MLU) in Germany and the Brazilian University of Pará have developed a climate-friendly alternative to conventional cement. Carbon dioxide (CO2) emissions can be reduced during production by up to two thirds when a previously unused overburden from bauxite mining is used as a raw material. The alternative was found to be just as stable as the traditional Portland cement. The results were published in Sustainable Materials and Technologies.

Houses, factories, staircases, bridges, dams—none of these structures can be built without cement. According to estimates, almost 6 billion tons of cement were produced worldwide in 2020. Cement is not only an important building material, it is also responsible for around eight percent of manmade CO2 emissions. "Portland cement is traditionally made using various raw materials, including limestone, which are burned to form so-called clinker," explains Professor Herbert Pöllmann from MLU's Institute of Geosciences and Geography. "In the process, the calcium carbonate is converted into calcium oxide, releasing large quantities of carbon dioxide." Since CO2 is a greenhouse gas, researchers have been looking for alternatives to Portland cement for several years.