Carbon-Storing Construction Materials from Biochar and Construction & Demolition Waste

Construction and Demolition Waste (CDW) represents one of the largest waste streams in Europe, accounting for more than one-third of total waste generation. Although recycling rates have improved, a significant proportion of CDW is still downcycled into low-value applications. At the same time, agricultural and forestry residues remain underexploited despite their potential for conversion into biochar.

Biochar is a carbon-rich material produced through thermochemical conversion of biomass. Due to its porous structure, carbon sequestration potential and functional properties, biochar can act as a performance-enhancing additive in cementitious and composite construction materials.

The project proposes an innovative circular approach that combines recycled aggregates from CDW with engineered biochar derived from regional biomass residues, producing next-generation low-carbon construction materials with improved environmental and functional performance.

Overall Objective

To develop, demonstrate and validate carbon-storing construction products by integrating recycled construction and demolition waste with biochar produced from agricultural and forestry residues.

Specific Objectives

1. Develop engineered biochar from regional biomass residues suitable for construction applications.

2. Optimize cementitious and non-cementitious formulations incorporating:

   • recycled aggregates,

   • recycled fines from CDW,

   • biochar.

3. Develop demonstrator products:

   • masonry blocks,

   • mortars,

   • rendering systems,

4. Validate performance under laboratory and real operating conditions.

5. Quantify environmental benefits through:

   • Life Cycle Assessment (LCA),

   • Carbon Footprint Assessment,

   • Circularity Indicators.

6. Create a replication roadmap for participating RIVCircular regions.

Innovation

1.      Material Innovation

Novel multifunctional construction materials combining:

• recycled CDW aggregates,

• engineered biochar,

• low-carbon binders.

2.      Environmental Innovation

Permanent carbon storage within construction products throughout their service life.

3.      Circular Economy Innovation

Creation of a closed-loop system linking:

Agriculture → Biochar Production → Construction Materials → Buildings → Future Recycling.