Transforming coffee waste: Australian innovation boosts concrete strength by 30%
Australian engineers have discovered a new use for coffee grounds in the construction industry, increasing their value. The waste, previously unused from the coffee brewing process, can significantly enhance the strength of concrete by almost 30%.
This information, published by "The Guardian," was presented in the "Journal of Cleaner Production." According to scientists from RMIT University in Melbourne, an innovative method of processing coffee residues has been developed, which can be used to create concrete with enhanced durability.
Adding modified coffee residues to the concrete mix can increase its resistance by 29.3%. Experts also note that this method uses an energy-friendly pyrolysis process.
How to strengthen concrete with coffee grounds?
Dr. Shannon Kilmartin-Lynch, a co-creator of this technology from RMIT, highlights the problem of unnecessary waste of coffee grounds and capsules. He emphasizes that this solution addresses the inefficient management of these wastes. Processed into biochar—a material resembling charcoal—they can replace part of the sand used in concrete production.
As Dr. Rajeev Roychand from RMIT explains, to prevent CO2 emissions, it is crucial to heat coffee residues in anaerobic conditions when creating biochar.
Pyrolysis, the central element of this method, involves heating the grounds to 350 degrees Celsius, an energy-efficient process. Scientists note that pyrolysis typically requires higher temperatures, reaching 900 degrees, but coffee needs little more than 350 degrees.
Benefits of using coffee wastes
Research shows that adding 15% coffee biochar to the concrete mix increases its strength by nearly 30%. Coffee wastes are porous, which facilitates the bonding of cement with biochar.
Although the RMIT team's research is still in its early stages, and further tests on material durability are necessary, scientists are already collaborating with local authorities to use reinforced concrete in future infrastructure projects, such as pavement construction.
Another advantage is the reduction in the amount of grounds reaching landfills. If all Australian coffee waste were recycled, 22,000 tonnes of eco-friendly concrete could be produced annually.
