Coffee Waste Could Make Concrete Stronger and Greener, Scientists Find
New research from RMIT University shows that spent coffee grounds can be transformed into biochar and used to replace a portion of sand in concrete, creating a stronger and more sustainable building material. Heating coffee waste at around 350°C without oxygen produces a fine biochar that boosts concrete’s 28-day strength by roughly 30% when used at 15% substitution. Life-cycle analysis shows the method can cut CO₂ emissions by up to 26%, supporting circular-economy construction and reducing reliance on natural sand.
