Construction Waste Sorting | AISORT
Application Overview — Construction & Demolition
C&D Waste Sorting in Modern Recycling Facilities
Construction and demolition (C&D) waste is the largest waste stream by volume globally, representing 30-40% of total solid waste in developed countries. C&D sorting recovers concrete (for aggregate), wood, metals, plastics, and gypsum — diverting material from landfill and producing recycled construction materials. Advanced C&D sorting can achieve landfill diversion rates above 90%.
Material Characteristics and Sorting Challenges
C&D sorting challenges: abrasive materials (concrete, brick, stone) cause rapid wear on conveyors, chutes, and sensors; material size ranges from dust to reinforced concrete beams; intertwined materials (wood with nails, concrete with rebar, insulation attached to drywall) are difficult to separate mechanically; and gypsum contamination of concrete aggregate causes sulfate problems in recycled aggregate applications.
Recommended Sorting Technology Stack
Pre-screening (trommel or vibrating screen to remove fines) → magnetic separation (rebar, structural steel) → manual/robotic picking (large items: wood beams, pipes, insulation panels) → NIR (plastic and wood identification) → XRT (density-based: concrete/brick vs lightweight materials) → eddy current (non-ferrous metals) → air classification (light fraction: paper, plastic film, insulation).
Performance Benchmarks
| Metric | Target |
|---|---|
| Landfill Diversion | >90% |
| Aggregate Purity | >99% (clean concrete) |
| Throughput | 20-100 t/h |
| Material | Mixed C&D, pre-screened |
These benchmarks represent achievable performance with modern sensor-based sorting equipment, assuming properly sized, well-maintained equipment operating on representative feedstock. Actual results depend on specific material composition, throughput, and operating conditions.