How to Recycle Concrete
Concrete and masonry debris from construction, demolition, and renovation projects containing valuable aggregates and cement components. Concrete recycling diverts over 95% of the 600 million tons of construction waste generated annually in the US, making it one of the most successfully recycled building materials with significant environmental and economic benefits.
- 1Allow concrete to cure completely (minimum 28 days) before processing for optimal strength
- 2Remove all rebar, wire mesh, and metal reinforcements using cutting tools or magnets
- 3Separate concrete from wood, plastic, asphalt, gypsum, and other contaminating materials
- 4Break large pieces into manageable sizes (under 24 inches) using hydraulic breakers
- 5Remove loose dirt, vegetation, and organic debris that can contaminate recycled aggregate
- 6Sort by concrete type and strength - separate structural from non-structural concrete
- 7Remove any hazardous materials like asbestos or lead-based coatings from older structures
- 8Load carefully to prevent cross-contamination with other construction materials
- 9Document source and age of concrete for quality control purposes
- 10Transport to certified recycling facility within 30 days to prevent weathering
- Construction and demolition recycling facilities (C&D processors)
- Concrete plants and ready-mix suppliers offering take-back programs
- Quarries and aggregate producers with mobile crushing operations
- Municipal solid waste facilities with C&D processing capabilities
- Road construction contractors using portable crushers on-site
- Specialty concrete recyclers with quality certification programs
- Building material suppliers offering aggregate exchange services
CRITICAL: Never mix concrete with gypsum-based materials (drywall, plaster) as this creates sulfate contamination that weakens recycled concrete. Pre-1970s concrete may contain asbestos - test before handling. Concrete recycling requires specialized crushing equipment and quality testing. Transportation distances over 50 miles may negate environmental benefits due to diesel fuel consumption and CO2 emissions.
Concrete recycling prevents 145 million tons annually from entering landfills while reducing virgin aggregate mining by 30-40%. Recycling 1 ton of concrete saves 100.4 kg CO2 emissions and reduces global warming potential by 8-24%. Over 95% recovery rate makes concrete the most recycled construction material. Recycled concrete aggregate uses 58% less energy than virgin materials and reduces transportation emissions when sourced locally. However, crushing operations contribute 24-66% of environmental impact.
- On-site crushing for immediate reuse as road base or fill material
- Mobile crushing services to process concrete at demolition sites
- Architectural salvage for decorative concrete elements
- Concrete rubble for erosion control and riprap applications
- Crushed concrete for landscaping and drainage projects
Accepted
- Reinforced and non-reinforced concrete from buildings and infrastructure
- Concrete sidewalks, driveways, and foundation elements
- Precast concrete panels, pipes, and structural elements
- Concrete masonry units (CMUs) and concrete blocks
- Bridge deck concrete and highway barrier materials
- Clean concrete demolition debris without contamination
- Cured concrete samples and test cylinders from quality control
Not Accepted
- Concrete contaminated with gypsum, wood, or organic materials
- Asbestos-containing concrete from pre-1980 construction
- Concrete with embedded utilities, conduits, or complex reinforcement
- Oil-stained or chemically contaminated concrete surfaces
- Concrete mixed with tar, roofing materials, or sealants
- Fresh or uncured concrete (less than 28 days old)
- Concrete with lead-based paint or other hazardous coatings
Estimated value: $5-15 per ton for clean concrete, $2-8 per ton for mixed C&D materials, cost savings of $10-30 per ton vs. virgin aggregate, avoided landfill fees of $30-80 per ton
- Crystalline silica dust from cutting and crushing operations
- Potential asbestos fibers in pre-1980 concrete structures
- Heavy metals from industrial concrete applications
- Alkali compounds that can cause skin and eye irritation
What's the quality difference between recycled and virgin concrete aggregate?
High-quality recycled concrete aggregate meets ASTM and DOT specifications for most applications. While slightly more porous than virgin aggregate, it performs equally well in road base, new concrete (up to 30% replacement), and fill applications when properly processed and graded.
How much does concrete recycling cost compared to landfill disposal?
Recycling typically costs $10-25 per ton including transportation, while landfill disposal costs $30-80 per ton plus hauling fees. The recycled aggregate value ($5-15/ton) often offsets processing costs, making recycling economically superior to disposal.
Can all types of concrete be recycled together?
Most concrete can be recycled together, but high-strength concrete, lightweight concrete, and specialty mixes should be separated for optimal recycling. Concrete with different aggregate types may require separate processing to maintain quality standards.
What happens to the rebar and metal reinforcement?
Metal reinforcement is separated using magnetic separators and cutting equipment, then sold as scrap metal. This steel recycling generates additional revenue ($100-300/ton) that helps offset concrete processing costs while recovering 95% of embedded metals.
How far can concrete be transported for recycling?
Economic transport distance is typically 25-50 miles. Beyond this, transportation emissions and costs may exceed environmental benefits. Mobile crushing at demolition sites eliminates transport and maximizes sustainability while reducing project costs.
Is recycled concrete as durable as new concrete?
Yes, when properly processed. Recycled concrete aggregate in new concrete mixes (up to 30% replacement) performs equally to virgin materials. For road base applications, recycled concrete often exceeds performance requirements due to its angular shape and interlocking properties.
What quality controls ensure recycled concrete meets specifications?
Certified facilities test gradation, absorption, soundness, and contaminant levels. Materials must meet ASTM C33 for concrete aggregate and AASHTO M43 for road base. Regular testing ensures consistent quality and compliance with engineering specifications.
Can concrete recycling handle reinforced concrete from buildings?
Yes, modern recycling facilities use hydraulic shears, magnetic separators, and specialized crushing equipment to process heavily reinforced concrete. The steel is recovered separately as valuable scrap metal, while concrete becomes high-quality aggregate.
What are the main barriers to concrete recycling?
Transportation distances, contamination with other materials, lack of local facilities, and specification restrictions in some jurisdictions. However, growing acceptance of recycled materials and environmental regulations are reducing these barriers significantly.
How does concrete recycling compare globally?
The US leads with 95% recovery rates, while Europe averages 75-85%. Asia is rapidly expanding capacity. Best practices include mobile crushing, quality certification, and specification acceptance that other regions are adopting to improve recycling rates.