Scientists have devised a method to recycle used coffee grounds to improve the strength of  concrete.

Engineers at RMIT University have discovered a method to significantly enhance the strength of concrete by nearly 30% by incorporating processed coffee grounds into the construction material.

This approach involves transforming discarded coffee grounds into biochar, a lightweight residue reminiscent of charcoal. This biochar then replaces a portion of the sand that is typically an essential ingredient in concrete production.

The inspiration for this pioneering technique stemmed from a laudable motive – to combat coffee waste in workplaces, according to the research team behind the innovation.

In a noteworthy collaboration, the researchers are currently partnering with local councils to envisage upcoming infrastructure projects, including the construction of walkways and pavements, which will employ this revolutionary concrete.

One of the most promising environmental aspects of this method is its potential to diminish coffee waste ending up in landfills, in addition to easing the demand for natural sand, a vital resource extensively used in the construction industry.

The National Food Waste Strategy Feasibility Study reveals that around 3% of the country’s annual greenhouse emissions stem from food waste. With approximately 75,000 tonnes of coffee waste being generated annually, the newly developed technique could notably contribute to waste reduction efforts.

Termed as pyrolysis, the method involves subjecting coffee waste to temperatures of about 350°C. Remarkably, the engineering team has managed to make this technique more energy-efficient by conducting the process at lower temperatures than customary.

Through careful experimentation, the researchers ascertained that by substituting 15% of the sand conventionally employed in concrete production with coffee biochar, the resulting material exhibited a remarkable surge in strength – an impressive 29.3% increase.