Australian engineers boost concrete strength with coffee grounds
Engineers from Australia have found an innovative way to use coffee grounds in the construction sector. This often overlooked byproduct of brewing coffee can significantly increase the strength of concrete by almost 30%.
These findings, reported by The Guardian, were published in the "Journal of Cleaner Production." A team of researchers from RMIT University in Melbourne developed a method for re-utilizing used coffee grounds that enhances the production of stronger concrete.
Adding processed coffee waste to the concrete mix can increase its strength by 29.3%. Scientists also emphasize that the pyrolysis process used in this method is energy efficient.
Concrete reinforced with used coffee grounds
Dr. Shannon Kilmartin-Lynch from RMIT, who contributed to the development of this technology, points out the issue of excessive waste of coffee grounds, including capsules. He highlights that this action is a response to inefficient coffee waste management. When converted into biochar—a substance similar to charcoal—coffee grounds can replace a certain percentage of sand necessary in concrete production.
Dr. Rajeev Roychand from RMIT explains that to produce biochar from coffee residues, it is crucial to roast the used grounds in anaerobic conditions to avoid carbon dioxide emissions.
Pyrolysis, a vital element of the method for producing stronger concrete, involves heating coffee waste to around 662 degrees Fahrenheit and is energy-efficient. This is because pyrolysis usually occurs at much higher temperatures, reaching up to 1652 degrees Fahrenheit, while coffee grounds require little more than 662 degrees Fahrenheit.
Research shows that incorporating 15% biochar from coffee grounds into the concrete mix increases its strength by almost 30%. Moreover, because coffee waste is a porous material, cement quickly bonds with the biochar.
Although the RMIT team's research is still in its early stages, and additional tests regarding material durability are necessary, scientists are already collaborating with local authorities. They aim to use coffee ground-reinforced concrete in upcoming infrastructure projects, such as building sidewalks.
Another significant benefit is the reduction of coffee grounds ending up in landfills. If all Australian coffee grounds were processed, up to 24,800 tons of this eco-friendly concrete annually could be produced.
