Australia’s caffeine capital is putting its grinds to good use as Victoria’s Big Build lays its first-ever batch of coffee-infused concrete.
Late last year, researchers from RMIT University proved they could put the nation’s love affair with the breakfast bean to work by transforming the millions of coffee waste produced every year into organic biochar that could replace sand in mixing concrete.
With the team claiming the biochar could increase the strength of concrete up to 30 per cent, reduce the amount of fine aggregate and cut down greenhouse gasses emitted from Australia’s notoriously pollution-heavy landfills, it’s not hard to see why investors’ ears perked up.
Now, 12 months after their discovery, the team is putting their findings to the test in a series of major infrastructure works in Melbourne suburbs.
For this project, road construction company BildGroup converted 5 tonnes of spent coffee grounds – about 140,000 coffees worth of grounds – into 2 tonnes of useable biochar, which has been laid into the 30 metres cubed footpath along McGregor Road in Pakenham.
And by all accounts, the coffee concrete is a resounding success, with the group’s CEO, Stephen Hill, saying the groundbreaking pathway project was paving the way forward for a more sustainable 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.”
And the biochar is only one of several circular economy initiatives delivered for the Pakenham Roads Upgrade which includes reusing in-fill soil and material for the Princes Freeway embankments and using foam bitumen and rubber tyre road barriers.
But Melbourne pathways are just a small stepping stone for coffee concrete, according to research team leader Professor Jie Li, with the biochar having the potential to help construction projects across the globe cut down on costs and waste.
Coming in at 10 grams a puck, this process has the ability to pull over seven and a half billion cups’ worth of coffee grounds out of landfills each year in Australia alone.
But if taken to a global scale, the 10 billion tonnes of coffee waste ending up in landfills has the potential to massively offset the 50 billion tonnes of sand used in construction projects every year, easing the strain placed on supply chains.
“The ongoing extraction of natural sand around the world – typically taken from river beds and banks – to meet the rapidly growing demands of the construction industry has a big impact on the environment,” said Li.
“There are critical and long-lasting challenges in maintaining a sustainable supply of sand due to the finite nature of resources and the environmental impacts of sand mining.
“With a circular-economy approach, we could keep organic waste out of landfill and also better preserve our natural resources like sand.”
