Humans are getting as creative with their used coffee grounds as they are with their brew methods. Last week we told you about used coffee being turned into biofuel, and now the New Scientist reports that it may soon be used to build roads.
Thanks to Arul Arulrajah, a professor of Geotechnical Engineering at Melbourne’s Swinburne University of Technology, used coffee grounds can now be used as a green alternative to traditional road building materials. Not only will this reduce the amount of waste finding its way to a landfill, but it will also reduce the demand for quarry materials such as stone and gravel, all of which require fuel to excavate and ship for new building projects.
The coffee bricks are made by drying the wet coffee slurry at a low heat (50°C, 122°F) and combining it into a mixture with slag, a byproduct of steel manufacturing. The mixture is then shaped into cylindrical blocks, which will serve as a foundation layer upon which concrete or other road-top materials are poured. Arulrajah estimates that five kilometers of road could be made each year from the waste at Melbourne shops alone.
There is still more research to be done before the new road material can go into production, like making sure the amount of energy needed to produce the coffee bricks doesn’t outweigh the recycling benefits. But finding real-world uses for coffee waste seems like a pretty smart idea—especially down in Melbourne, where they've got heaps of the stuff.
Zac Cadwalader is the news editor at Sprudge Media Network.
*Top image via Coffeesnobology