Performance Optimization and Carbon Reduction Potential of Bamboo Biochar for Lightweight Artificial Aggregates

Area of Science:

• Materials Science
• Environmental Engineering
• Sustainable Construction

Background:

• Efficient utilization of biochar and construction solid waste is crucial for developing sustainable building materials.
• Existing lightweight aggregates often lack optimal engineering properties and environmental benefits.
• Novel aggregate designs are needed to incorporate waste materials effectively.

Purpose of the Study:

• To develop and characterize novel core-shell artificial aggregates using biochar and construction waste.
• To evaluate the engineering properties of these aggregates, including crushing strength, water absorption, and bulk density.
• To assess the potential for carbon dioxide sequestration during the curing of these artificial aggregates.

Main Methods:

• Preparation of core-shell artificial aggregates by encapsulating coarse-particle bamboo biochar with concrete slurry waste and calcium carbide slag.
• Incorporation of fine-particle bamboo biochar into the shell matrix.
• Testing of engineering properties and evaluation of CO2 uptake under a CO2 curing system.

Main Results:

• Optimal engineering properties were achieved with approximately 6% fine-particle bamboo biochar content.
• The best-performing aggregates exhibited a crushing strength of 4.7 MPa, water absorption of 14.3%, and bulk density of 796 kg/m³.
• Artificial aggregates with 6% fine-particle bamboo biochar achieved 5.72% CO2 uptake, attributed to enhanced CO2 transport channels.

Conclusions:

• The novel core-shell aggregates demonstrate superior engineering properties compared to commercial lightweight aggregates.
• These aggregates offer significant potential for CO2 sequestration, contributing to carbon neutrality in the construction industry.
• This innovation opens new avenues for the sustainable application of biochar in building materials, providing both engineering and environmental advantages.