Biochar-Based Bricks to Reduce Carbon Intensity of the Built Environment

Turning Tree Waste into Low-Carbon Bricks

Bricks are a ubiquitous construction material across the globe due to their durability and excellent physical, mechanical, and thermal properties. However, the kilns used to cure most bricks can damage soil and workers’ health, consume large amounts of energy and emit significant amounts of greenhouse gases. Concrete bricks are typically manufactured by mixing Portland cement, aggregate (e.g., sand), and water, followed by forming the mixture in a mold and compressing via hydraulic pressure.

The greatest climate change impacts attributed to brick production come from the extraction and sourcing of raw materials, such as limestone. One way to reduce the environmental impact of brick production is to evaluate alternative feedstocks and wastes for inclusion in the bricks.

This project aims to address this issue by using biochar as a functional performance additive in building materials, which can move us toward carbon neutrality. Waste from red oak trees impacted by oak wilt will be used in biochar production to help the health of tree canopies in the Twin Cities and provide financial incentives for utilizing tree waste.

Project Goals

• Procure red oak tree biochar from the City of Minneapolis
• Design, develop and evaluate the performance of biochar-containing bricks
• Design and install two small-scale structures at the Tamales Y Bicicletas urban farm
• Conduct a preliminary life cycle assessment to quantify the potential environmental impacts of the new biochar-containing bricks compared to traditional bricks regarding resource consumption, carbon footprint, human/ecosystem toxicity and other impact categories
• Communicate results to a broad range of stakeholders, including scientific peers, industry stakeholders and the public