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Used coffee grounds were charred at 350 degrees Celsius until they became a charcoal-like biochar. That material replaced 15 percent of the sand by volume in a concrete mix (scienceblog.com)
submitted 2 months ago by to c/environment@sh.itjust.works
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[–] 10 points 2 months ago (2 children)

While it's nice to use a bit less sand, charring at 350°C doesn't sound like negligible energy usage. Especially if done with fossils. Always good to have options, I guess?

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  • [–] 3 points 2 months ago (1 child)

    Last I heard we are running out of sand to use in concrete so it might not be an environmental thing just a cost. Like they can’t just use any ol’ sand. Beach sand is too smooth or something so it has to be river sand I believe.

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  • [–] 5 points 2 months ago

    Other way around. Beach sand is new and this rough. A surprising amount of it is parrotfish poo, chewed up coral. River sand, and desert sand, is weathered and smooth.

    I've seen a machine for pulverizing glass bottles into basically sand. Smooth desert sand > glass packaging, used for food, glass packaging > concrete aggregate?

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