Researchers at RMIT University, in collaboration with contractor BildGroup, Major Road Projects Victoria, and biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More producer Earth Systems, have successfully integrated spent coffee grounds biochar into a 30-cubic-meter infrastructure project in Australia. The project utilized concrete containing spent coffee grounds biochar along McGregor Road in Pakenham as part of Victoria’s Big Build infrastructure initiatives. By incorporating two tonnes of pyrolyzed organic carbon into the concrete mix, the project successfully replaced natural river sand while establishing a viable commercial pathway for organic waste in heavy civil construction.

The primary obstacle addressed by this initiative is the environmental degradation and material instability associated with incorporating raw organic waste directly into structural concrete. Untreated spent coffee grounds decompose inside concrete matrices over time, severely compromising structural integrity and compressive strength. Additionally, global construction relies heavily on finite natural river sand resources, while urban organic waste sent to landfills accelerates methane and carbon dioxide emissions. Establishing an auditable, low-energy thermal transformation process was necessary to convert volatile organic waste into a stable aggregate capable of meeting rigorous civil engineering standards.

To resolve these technical and environmental constraints, Earth Systems processed five tonnes of spent coffee grounds—representing roughly 140,000 processed cups of coffee—into two tonnes of high-density biochar. RMIT University researchers developed a low-energy pyrolytic framework, heating the organic waste to 350 degrees Celsius in an oxygen-deprived environment. This conversion process immobilized the volatile organic compounds and produced a carbon-dense matrix suitable for replacing up to 15 percent of standard river sand in concrete formulations. BildGroup then poured the biochar-amended concrete mix for the Pakenham infrastructure asset.

The real-world deployment yielded quantifiable environmental and structural benefits, successfully diverting five tonnes of organic waste from municipal landfills and directly replacing over three tonnes of natural river sand. Laboratory baseline testing confirmed that coffee biochar incorporation can increase concrete compressive strength by up to 30 percent, offering potential future opportunities to reduce total cement content by 10 percent. Ultimately, the Pakenham footpath trial demonstrates an operational blueprint for scaling pyrogenic carbon applications across civil infrastructure, validating biochar as a functional alternative aggregate in global construction supply chains.