Using coffee grounds to produce concrete

Researchers at RMIT University in Melbourne, Australia, have heated coffee waste without oxygen (a process called pyrolysis) to create biochar that can replace up to 15% of the sand used in concrete mixes. Lead researcher Rajeev Roychand said adding biochar to the concrete mix would increase the strength of the concrete by 30% and reduce the amount of cement needed by 10%.

Concrete with biochar made from coffee grounds. Photo: RMIT University

Millions of tons of used coffee grounds are used globally, and most of them end up in landfills, where they release methane gas as they decompose. Globally, biochar from coffee waste could replace up to 90 million tons of concrete-mixing sand, Roychand said. Concrete production, which involves mixing sand and gravel with cement and water, is a major source of greenhouse gases, accounting for about 7% of the world’s emissions, according to the United Nations. A 2022 UN report also found that about 50 billion tons of sand are dug up each year, mostly for use in concrete. Sand mining often wreaks havoc on the environment and contributes to ever-increasing shortages.

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Source: https://www.sggp.org.vn/dung-ba-ca-phe-de-san-xuat-be-tong-post741347.html