Innovations in Green Concrete: Combining Metakaolin and Arundo Grass Biochar for Enhanced Sustainability

Cement production is a major contributor to greenhouse gas (GHG) emissions, driving the need for alternative materials to reduce its environmental footprint and enhance sustainability. This study investigates the use of biochar derived from Arundo grass as a partial replacement for cement in conjunction with metakaolin to enhance the mechanical properties and environmental performance of concrete. Compressive strength analysis and sorptivity analysis were conducted to evaluate the effects of metakaolin on Arundo grass biochar concrete. The findings revealed that incorporating biochar and metakaolin negatively impacted workability. However, a mixture of 5% biochar and 10% metakaolin (by weight of cement) significantly improved early 7-day compressive strength compared to samples containing only 5% biochar and the control mix. Additionally, the sorptivity analysis indicated that this combination maintained comparable absorption rates to the control sample. In terms of sustainability, the partial replacement of cement with 5% biochar and 10% metakaolin reduced CO2 emissions by 75 kg per cubic meter of concrete, showcasing its contribution to lowering the carbon footprint of concrete production. Overall, this study demonstrates the potential of combining biochar and metakaolin to develop more sustainable concrete solutions with enhanced early compressive strength. However, further research is needed to optimize long-term performance and workability for broader adoption in sustainable construction practices.