Introduction
Concrete can be made 29% stronger by incorporating recycled coffee grounds. This presents an opportunity to divert the millions of tonnes of spent coffee grounds produced globally each year from ending up in landfills, where they emit methane – a greenhouse gas with a warming effect much stronger than carbon dioxide.
The Research
A team of researchers at RMIT University in Melbourne, Australia, collected used coffee grounds from local cafes and explored their potential use as a replacement for sand in concrete. Initially, the coffee grounds weakened the concrete when used as a direct substitute for sand. However, when the grounds were heated in a controlled environment to create a charcoal-like substance called biochar, they became more useful in enhancing the strength of the concrete.
Replacing 15% of the sand component in concrete with biochar resulted in concrete blocks that were 29% stronger compared to conventional blocks. The researchers believe that the porous structure of biochar may be the reason behind this increased strength. Biochar has the ability to trap moisture, preventing the concrete from drying out on the inside and developing micro-cracks that can weaken its structure.
Potential Applications
The research team is now looking to collaborate with councils and industry groups to conduct field trials of their coffee biochar-enhanced concrete. Several councils that face challenges in disposing of organic waste have already expressed interest in this work. By finding new applications for used coffee grounds, such as incorporating them into building materials like concrete, the emissions of methane from landfills can be reduced, contributing to the fight against climate change.
Conclusion
The use of recycled coffee grounds as a component in concrete has shown potential for strengthening the material. By diverting coffee grounds from landfills and utilizing them in a beneficial way, we not only strengthen concrete but also reduce methane emissions, addressing two environmental challenges simultaneously. With further research and field trials, this innovative approach could become a sustainable solution in the construction industry.
