How Biochar-Enhanced Concrete Turns Forest Thinnings into Low Carbon Building Materials

The Built Environment’s Carbon Dilemma

Buildings generate 37% of global greenhouse gas emissions. While operational energy efficiency has improved, reducing the embodied carbon of structural materials remains a critical bottleneck. Concrete relies heavily on energy-intensive Portland cement, which provides essential strength and durability but carries a severe carbon cost. Alternative binder replacements often risk compromising mechanical performance, long-term durability, or regulatory compliance.

Decoupling Strength from Carbon: The Biochar Innovation

This research investigates viable low-carbon alternatives to Portland cement that decouple structural integrity from high-embodied-carbon chemistry. By targeting the fundamental material synthesis of binders, this project aims to develop high-performance, scalable concrete formulations that dramatically reduce carbon intensity while meeting or exceeding traditional performance and regulatory benchmarks.

To address cement emissions, the team formulated high-performance bricks by replacing a portion of Portland cement with biochar—a stable, carbon-sequestering material derived from waste wood and forest thinnings.

To evaluate real-world weathering and durability, prototype bricks were deployed at Tamales y Bicicletas, an urban greenhouse in Minneapolis, MN.

NRRI’s Role

Natural Resources Research Institute (NRRI) co-led the field demonstration with Tamales y Bicicletas, conducted the Life Cycle Assessment (LCA) to quantify environmental benefits against traditional materials, executed voice-of-customer interviews to outline commercialization pathways, and is co-leading next steps toward commercialization.

Key Results

• Process & Formulation: Developed manufacturing workflows from waste wood collection to brick curing, evaluating 15 distinct biochar-cement mix designs to optimize binder synthesis.
• Environmental Impact: Conducted a preliminary Life Cycle Assessment (LCA) confirming biochar bricks deliver a lower overall carbon footprint and reduced environmental impact compared to conventional masonry.
• Application Readiness & Technical Know-How: Established baseline engineering data to apply biochar-concrete formulations to broader sustainable construction applications.

Project Impact

• Decarbonizing Construction: Demonstrates a scalable material pathway toward achieving net-zero emissions targets in the built environment by 2050, directly aligning with Minnesota’s Climate Action Framework.
• Forest Health & Fire Mitigation: Creates a high-value commercial market for low-value waste wood, small-diameter timber, and forest thinnings that would otherwise increase catastrophic wildfire risks.
• Rural Economic Growth: Supports regional manufacturing and forest management economies across Minnesota through value-added timber utilization.

Conclusions

This project demonstrates a viable pathway for sustainable construction by integrating carbon-sequestering biochar into high-performance structural materials. By bridging the gap between fundamental environmental engineering and commercial deployment, this work sets the stage for broad-scale adoption of low-carbon masonry.

Next Steps & Future Research

• Performance & Durability: Continue refining physical and mechanical properties while evaluating long-term structural durability under severe environmental exposure.
• Environmental & Urban Benefits: Investigate the bricks' performance as functional living patinas to help mitigate urban heat islands and atmospheric pollutants.
• Commercial Viability: Expand market feasibility studies and scale up production workflows for regional deployment.

Collaborators & Partners

• Tamales y Bicicletas: José Luis Villasenor
• City of Minneapolis: Jim Doten
• University of Minnesota:
  • Dr. Malini Srivastava, College of Design
  • Dr. Mihai Marasteanu, College of Science and Engineering
  • Dr. Emilie Snell-Rood, College of Biological Sciences
  • Dr. SunMin May Hwang, College of Design
  • Lindsey Kemmerling, College of Biological Sciences
  • Matt Aro, Natural Resources Research Institute

Funding Acknowledgement

• University of Minnesota, Institute on the Environment Impact Goals program
• University of Minnesota, Bioinnovation Accelerator program

Contact Information

For media and PR contact:

Jamie Alexander, Director External Affairs

Email: [email protected] | Office: (218) 788-2797

For research contact:

Matthew Aro, Research Program Manager, Sustainable Building Materials

Email: [email protected] | Office: (218) 788-2700