We all love our coffee, but coffee concrete – that’s a new one! In the latest Insights article, we discuss what coffee concrete is and how our humble morning coffee could be a sustainable game changer in the construction industry.
At BildGroup, we’re passionate about sustainability and finding innovative ways to reduce waste in construction. One of our latest projects, in partnership with RMIT and our concrete supply partner Dandy Premix, is an exciting example of how we’re leading the way with eco-friendly solutions—specifically using biochar to create coffee concrete.
So, what exactly is biochar?
Biochar is a form of charcoal produced by heating organic waste materials like coffee grounds or wood chips in a low-oxygen environment, known as pyrolysis. This transforms the waste into a stable, carbon-rich material for various applications, including construction.
Globally, 10 billion kilograms of spent coffee is generated annually, which could replace up to 90 billion kilograms of sand in concrete.
With RMIT, we are trialing biochar in concrete as part of the Pakenham Roads Upgrade with MRPV and the Cardinia Shire Council. As part of this trial, we have poured over 30 cubic metres of coffee concrete to create a brand-new footpath for the council. This innovative concrete mix contains biochar made from spent coffee grounds, replacing traditional sand used in concrete.
Why is this important?
For one, sand is a finite resource. At the same time, around 3% of Australia’s total landfill is made from coffee grounds. We can make a significant environmental impact using biochar from coffee grounds instead of sand. For this project alone, we’ve diverted five tonnes of coffee grounds from landfills, turning them into over two tonnes of biochar. That’s the equivalent of saving nearly 139,000 lattes from being wasted! Additionally, we’ve saved three tonnes of sand, preserving this precious resource.
The benefits of biochar don’t stop there. RMIT’s research shows it makes concrete up to 30% stronger, opening potential cost savings for construction companies, as we could reduce the amount of cement needed by as much as 10%, which benefits both the environment and business.
This initiative is truly a team effort. Working closely with Reground, who provided the coffee grounds, and Earth Systems, who created the biochar, we’ve been able to help bring coffee concrete to life—an industry-first for the Australian construction sector. RMIT is also expanding its research to explore using biochar made from other organic materials, like wood chips, which could offer even more benefits.
We are proud to be at the forefront of this circular economy solution with our partners, turning organic waste into valuable resources like biochar.
References
Transforming spent coffee grounds into a valuable resource for the enhancement of concrete strengthis published in the Journal of Cleaner Production. (DOI: 10.1016/j.jclepro.2023.138205). RMIT co-authors are Dr Rajeev Roychand, Dr Shannon Kilmartin-Lynch, Dr Mohammad Saberian, Professor Jie Li, Professor Guomin (Kevin) Zhang and Professor Chun-Qing Li.
