Where did the story of French croissants begin, and what’s the difference between a croissant au beurre and a croissant ordinaire? Discover how this pastry became a breakfast icon worldwide – from Parisian bakeries to Japanese convenience stores – and learn how to bake croissants at home, step by step.
Can coffee grounds be useful in construction?
Coffee grounds are finding applications in an increasing number of industries—but is it time for them to be used in construction as well? Recent research from Australia suggests that the answer might be yes.
Can used coffee grounds be repurposed?
Instead of ending up in the trash, coffee grounds can be reused in many ways. They are already used in cosmetics and exfoliating scrubs, and in gardening as a natural fertilizer. Now, researchers are exploring new possibilities—one of the most promising being reinforcing concrete with coffee grounds.
Coffee grounds and concrete: giving coffee a second life
A team of engineers from RMIT University in Australia has developed a method to strengthen concrete by adding coffee grounds. According to their research, the presence of coffee in concrete can increase its strength by up to 30%!
What inspired this research?
Scientists recognized that used coffee grounds are a major type of organic waste that frequently ends up in landfills. The disposal of organic waste poses a challenge due to the large amounts of greenhouse gases it emits, including methane and carbon dioxide, which contribute to climate change.
In response, researchers investigated how coffee waste could be recycled and transformed into a valuable raw material rather than a waste product.
The potential of coffee grounds in the concrete industry
The concrete industry emerged as a promising candidate for coffee waste recycling. However, due to the high organic content of coffee grounds, researchers had to apply a pyrolysis process—a method of heating organic material at high temperatures in an oxygen-free environment.
To assess coffee’s suitability for improving concrete’s physical and mechanical properties, scientists experimented with various pyrolysis temperatures and tested coffee grounds as a replacement for fine aggregates (such as sand) in different proportions.
What were the results?
The study found that pyrolyzing used coffee grounds at 350°C significantly improved concrete properties. The most notable result was an increase in compressive strength by 29.3% when 15% of sand was replaced with coffee-based biochar.
The research team suggests that processed coffee waste could replace sand in traditional concrete mixtures in the future. This would not only strengthen concrete but also reduce the need for natural sand extraction from riverbanks, addressing both construction material shortages and environmental concerns.
A 2020 study referenced by the researchers estimated that Australia alone generates approximately 75,000 tons of coffee waste per year—a substantial resource that could be put to better use.
What’s next for coffee-infused concrete?
While further testing is needed, the study’s findings indicate that coffee-based concrete could play a role in making construction more sustainable.
For more details, the full study can be found in the Journal of Cleaner Production.
