step process used by Swinburne University Professor Arul Arulrajah and PhD candidate Teck-Ang Kua to convert coffee grounds into subgrade material that can be used for road construction.
Coffee grounds dried in a 50°C oven for five days, then sieved to filter out lumps.
Mixture comprising seven parts coffee grounds and three parts of slag – a waste product from steel manufacturing. A liquid alkaline solution was added to bind everything together.
The mixture was compressed into cylindrical blocks that proved strong enough to use as the subgrade material that sits under a road surface.
or even as low as 10,000 tonnes of coffee, the “rough estimate" according to Prof. Arul needed in order to produce 5 kilometres of road. This research is a collaboration with Suranaree University of Technology, Thailand; Southeast University, Nanjing, China; and Shanghai Jiao Tong University, China