The Victorian Government’s Pakenham Roads Upgrade is the first major infrastructure project to use coffee concrete – an innovation developed by RMIT University.
Major Road Projects Victoria (MRPV) and project contractor BildGroup have used concrete mixed with biochar made from spent coffee grounds, as a replacement of a portion of the river sand that is normally used, in the Pakenham Roads Upgrade.
Organic waste going to landfill, including spent coffee grounds, contributes 3 per cent of greenhouse gas emissions. This waste cannot be added directly to concrete because it would decompose over time and weaken the building material, which is why the used coffee is converted into biochar before being added to the concrete mix.
Australia generates 75 million kilograms of ground coffee waste every year – most of it goes to landfills, but it could replace up to 655 million kilograms of sand in concrete because it is a denser material. Globally, 10 billion kilograms of spent coffee is generated annually, which could replace up to 90 billion kilograms of sand in concrete.
For this project, Earth Systems converted five tonnes of spent coffee grounds – about 140,000 coffees worth of grounds – into two tonnes of useable biochar, which has been laid into the 30 metres cubed footpath along McGregor Road in Pakenham.
The use of coffee biochar is one of several circular economy initiatives delivered for the Pakenham Roads Upgrade that include reusing the in-fill soil and material for the Princes Freeway embankments and using foam bitumen and rubber tyre road barriers.
MRPV Program Director Brendan Pauwels said coffee concrete had the potential to cut costs and remove vast amounts of waste material from landfill.
“These numbers are remarkable in terms of ecological benefit, and we’re excited to see the Pakenham Roads Upgrade be the first Victorian Big Build project to use the coffee concrete,” he said.
RMIT Postdoctoral Research Fellow Dr Rajeev Roychand, the lead inventor of the coffee concrete, was excited to partner with BildGroup and MRPV for the translation of the RMIT team’s research into Victorian government’s Big Build projects.
“This proactive support plays a significant role in creating a potential for diverting all forms of biodegradable organic waste, which is currently ending up in landfills and contributing to 3% of Australia’s greenhouse gas emissions,” Roychand said.
BildGroup CEO Stephen Hill, an RMIT alumnus, said he was happy for the company to lead the way and be the first to bring coffee concrete to a major infrastructure project for the Australian construction industry.
“With the coffee concrete we’ve poured, we’re diverting an estimated 140,000 coffees from landfill and saving over 3 tonnes of sand, which have enormous environmental benefits,” he said.
“From a triple bottom line perspective, this just makes good business sense.”
Read more about the original study here.
