Demolition waste

Composition

In 2014, 505.1 million tons of demolition debris was generated in the US. Out of the 505.1 million tons, the debris was composed of 353.6 million tons of concrete, 76.6 million tons of asphalt concrete, 35.8 million tons of wood product, 12.7 million tons of asphalt shingles, 11.8 million tons of brick and clay tile, 10.3 million tons of drywall and plaster, and 4.3 million tons of steel.

Disposal

Before demolition debris is extracted, contamination from lead, asbestos or other hazardous materials must be resolved. Hazardous materials must be disposed of separately, according to federal regulation. Alternatively, debris may also be sorted and recycled. Sorting may happen as deconstruction on the demolition site, off-site at a sorting location, or at a Construction and Demolition recycling center. Once sorted, materials are managed separately and recycled accordingly.

Recycling

Concrete and Brick

Main article: Concrete recycling

Concrete and brick can be recycled by crushing it into rubble. Once sorted, screened and contaminants are removed, reclaimed concrete or brick can be used in concrete aggregate, fill, road base, or riprap. Mobile concrete crushers also allow for recycling of concrete on-site.

Wood

Main article: Timber recycling

Wood can be reused, repurposed, recycled, or burned as bioenergy. Using recycled wood as a bioenergy feedstock is advantageous because it has lower water content, about 20% water, compared to virgin lumber, about 60% water.

Drywall

Drywall is made primarily of gypsum. Once the gypsum is depapered, it can be added in cement production, as a soil amendment, used in aerated composting, or recycled into new drywall. Gypsum recycling can be particularly beneficial because in landfill conditions gypsum will release hydrogen sulfide, a toxic gas.

Asphalt

Asphalt, from shingles or asphalt concrete, is typically recycled and used in pavement.

Metal

Main article: Scrap

Scrap metal is an established industry focused on the collection, buying, selling, and recycling of salvaged materials.

References

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References

1. (8 March 2016). "Sustainable Management of Construction and Demolition Materials".
2. (November 2016). "Advancing Sustainable Materials Management: 2014 Fact SheetAssessing Trends in Material Generation, Recycling, Composting, Combustion with Energy Recovery and Landfilling in the United States".
3. (31 January 2013). "Harmful Materials and Residential Demolition".
4. "Construction and Demolition Debris (C&DD)". Ohio EPA Division of Materials and Waste Management.
5. (7 February 2017). "Compliance Bulletin: Asphalt, Brick and Concrete Recycling & Beneficial Use, February 2016".
6. (2012). "Recycling Wood Pallets and Packaging".
7. (2016-09-20). "Scrap Metal Merchants Sector".