The construction industry accounts for 5-7% of global CO2 emissions, largely due to the extensive use of cement. To combat this, researchers have explored biochar— a carbon-rich material derived from waste biomass— as a potential solution for sequestering CO2 in construction materials like shotcrete.

A recent study investigated the effect of biochar on shotcrete’s mechanical properties and its carbon sequestration capacity under various conditions, including carbonation curing and different temperature settings. The study found that incorporating 5% biochar into shotcrete enhanced both compressive and splitting strength by densifying its microstructure. However, increasing biochar content to 10% further boosted carbon sequestration but slightly weakened the material’s mechanical properties.

The researchers also noted that low temperatures negatively impacted the performance of biochar shotcrete. Nevertheless, the findings highlight the potential of biochar to fill concrete pores, thus improving its overall structure while offering a sustainable means of CO2 reduction.

With more research, biochar-infused shotcrete could become a key strategy in reducing the construction sector’s carbon footprint. By combining biochar with slurry materials used in mine shaft and roadway construction, there is the possibility of offsetting significant CO2 emissions, offering a promising step toward carbon neutrality in the industry.

This study opens new avenues for enhancing carbon capture in building materials, making biochar a valuable resource in sustainable construction.