Boosting concrete strength with coffee: Australian engineers innovate
Engineers in Australia have discovered a new use for coffee grounds in the construction industry, significantly increasing their value. Previously unused waste from the coffee brewing process can boost the strength of concrete by nearly 30%.
This discovery, reported by The Guardian, was detailed in the Journal of Cleaner Production. Researchers from RMIT University in Melbourne have developed an innovative method for processing coffee leftovers to create concrete with enhanced durability.
Adding modified coffee residues to the concrete mix can increase its strength by 29.3%. Experts also highlight that the pyrolysis process used in this method is energy-efficient.
How to strengthen concrete with coffee grounds?
Dr. Shannon Kilmartin-Lynch from RMIT, a co-developer of this technology, draws attention to the issue of wasteful disposal of coffee grounds and capsules. He emphasizes that this solution addresses inefficient waste management. When processed into biochar—a material similar to charcoal—they can replace some of the sand traditionally used in concrete production.
Dr. Rajeev Roychand from RMIT explains that in the process of creating biochar from coffee residues, it is crucial to heat them under anaerobic conditions to prevent CO2 emissions.
Pyrolysis, the central element of this method, involves heating the grounds to 662 degrees Fahrenheit. According to scientists, this is an energy-efficient process. Typically, pyrolysis requires much higher temperatures, up to 1652 degrees, but for coffee, little more than 662 degrees is needed.
Advantages of using coffee waste
Research indicates that by adding 15% coffee biochar to the concrete mix, its strength can increase by almost 30%. In addition, the porous nature of coffee waste facilitates the bonding of cement with biochar.
Although RMIT's research is still in the early stages and further durability tests are needed, scientists are already working with local authorities to use enhanced concrete in future infrastructure projects, such as sidewalk construction.
An additional benefit is the reduction of coffee grounds ending up in landfills. If all of Australia's coffee waste were recycled, it could produce up to 24,800 tons of eco-friendly concrete annually.
