Zou, et al (2024) Biochar-enabled carbon negative aggregate designed by core-shell structure: A novel 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 utilizing method in concrete. Construction and Building Materials. https://doi.org/10.1016/j.conbuildmat.2024.138507

A new study introduces a biochar-enabled, carbon-negative aggregate for use in concrete, designed using an innovative core-shell structure. This method aims to reduce the environmental impact of construction materials by combining biochar with cementitious materials. The aggregate is produced through cold-bonding, which is more environmentally friendly compared to high-temperature production methods typically used for lightweight aggregates.

The core-shell aggregate (CSA) consists of a lightweight biochar core encapsulated by a high-strength cementitious shell. This structure enhances both the mechanical performance and sustainability of the aggregate, overcoming biochar’s usual limitations, such as high porosityPorosity of biochar is a key factor in its effectiveness as a soil amendment and its ability to retain water and nutrients. Biochar’s porosity is influenced by feedstock type and pyrolysis temperature, and it plays a crucial role in microbial activity and overall soil health. Biochar More and water absorption. The new biochar-CSA exhibits a compressive strength of 6.84 MPa, a density of 789 kg/m3, and impressive strength efficiency compared to conventional lightweight aggregates. Moreover, it offers a carbon-negative footprint, emitting -69 kg of CO2 per ton during production.

When used to replace 90% of natural aggregate in concrete, the biochar-CSA maintains a compressive strength of 42.2 MPa and a reduced density of 1866 kg/m3, meeting standards for lightweight structural concrete. This makes it a promising alternative for addressing both the carbon emissions and natural aggregate shortages in the construction industry. The study highlights the potential of biochar as a sustainable material, providing a path toward greener concrete production.