Biochar as a Sustainable Component of Low-Emission Building Materials

Area of Science:

• Materials Science
• Environmental Science
• Sustainable Construction

Background:

• Biochar (BC), produced from wood biomass pyrolysis, is a potential sustainable additive for cementitious mortars.
• Its properties vary with pyrolysis temperature, influencing performance and environmental impact.

Purpose of the Study:

• To investigate the effect of biochar produced at different pyrolysis temperatures (450°C, 550°C, 700°C) on cementitious adhesive mortar performance.
• To evaluate physicochemical properties, mechanical/adhesive strength, VOC emissions, contaminant leachability, and conduct a life-cycle assessment (LCA).

Main Methods:

• Physicochemical characterization of biochar and mortars.
• Mechanical and adhesion testing of mortars with varying biochar content (1-5%).
• VOC emission analysis, leachability tests, and LCA.

Main Results:

• Biochar produced at 700°C showed high carbon content, alkaline pH, and porosity; biochar at 450°C had better sorption and functional groups.
• 1-5% biochar incorporation improved mortar performance, but higher doses reduced adhesion.
• VOC and metal leachability were generally within safe limits.
• LCA indicated a potential carbon footprint reduction of up to 35% by substituting mineral fillers with biochar.

Conclusions:

• Biochar is a promising, safe, and environmentally beneficial additive for low-emission construction materials.
• Optimizing biochar production and dosage is key for maximizing benefits in mortars.
• Utilizing biochar aligns with circular economy principles and climate-neutral objectives.