Coffee Ground Concrete: Sounds Absurd, But It Works (3 Photos)

Concrete’s sustainability problem could be solved in the coming years, and spent coffee grounds—which normally go unused and emit methane—might be the key. What if we used them in concrete instead of sand?

First, the grounds were heated to 350 degrees to remove oxygen, forming a porous, carbon-rich biochar. When added to the cement mix, it created a strong bond with all the components.

The result? This "coffee concrete" is 30% stronger than traditional concrete.