C&D WASTE SCREENING
What Is Construction & Demolition Waste?
Construction and demolition (C&D) waste is material that is generated from the renovation or demolition of structures, including homes and roadways or pavements.
C&D waste is comprised of many materials, but most commonly consists of:
Historically, much of this material has ended up in landfills. In recent years, there has been an effort to establish more sustainable practices and recover C&D materials for reuse as construction aggregate.
Aggregates Equipment, Inc. (AEI) is a leader in equipment manufacturing for screening C&D waste. Our custom-designed screening equipment delivers efficient, cost-effective solutions for applications within demolition waste materials recovery. And with waste generation on the rise, efficient material recovery has never been more important.
C&D Waste Production Trends
The Environmental Protection Agency (EPA) estimates there were 600 million tons of C&D debris generated in the United States in 2018. This is a significant increase over previous decades. In 2003, the EPA estimates only 170 million tons of C&D materials were generated.
With increasing initiatives to reduce waste and sustainably manage resources, more C&D waste material is recovered for “next use.” The term “next use” describes material that is diverted from landfills and used again for other means, such as aggregate, compost, or mulch. Aggregate is the most common next use for C&D debris.
The push for greater sustainability in construction practices has helped the C&D recycling industry grow. Allied Market Research estimates the global C&D waste recycling market size was $126 billion in 2019. The market is projected to increase to $149 billion by 2027.
How C&D Waste Is Screened And Recovered
Screening C&D waste has two primary functions:
- Separating different types of material, e.g. metal from concrete
- Sorting materials by size, e.g. separating pebbles from gravel
Depending on the composition of the C&D waste, the material recovery process will differ. However, a general screening process may follow these steps:
- Disc or trommel screening to sort materials by size
- Magnetic separation to remove ferrous metals
- Air classification to sort lighter materials, e.g. paper or plastic, from heavy materials
- Manual separation pulling wood, non-ferrous metal, and other materials
Pre-screening audits may be conducted which alter the screening process. For example, waste that is known to consist mostly of concrete may not need to pass through air classification.
The Challenges Of Screening C&D Waste
While the market for C&D waste continues to grow, efficient equipment needed to process larger quantities of waste and tighter material quality regulations both pose unique challenges.
Functional and Reliable Technology
Increases in waste production and higher demand for next use materials make efficient production paramount for a successful recovery operation. However, screening and separating inefficiencies can occur when outdated technology is used in recovery operations.
Traditional trommels and vibrating screens are often used for materials sizing. Eliminating undersized fractions is necessary for maintaining material purity. However, trommels and traditional vibrator screens are problematic in that their media is prone to blinding and plugging. Clearing and replacing screen media results in extended downtime and maintenance costs for recovery facilities, a challenge that modern screening technology, like disc screens, can help overcome.
Quality of Recovered Material
Recovered concrete from demolition projects is often repurposed as Recycled Concrete Aggregate. Recycled concrete must meet tight purity and sizing specifications for next use concrete production. This requires the concrete or asphalt C&D waste to be thoroughly screened.
Traditional screening equipment, like trommels, are less efficient at meeting these product specifications. Modern solutions are required to replace older forms to achieve the best results and maximize recovery efficiency.
AEI’s C&D Waste Screening Equipment
The Freedom Disc Screen
Compared to trommel screens, disc screens are better suited for C&D materials recovery. AEI’s Freedom Disc Screen uses profiled HARDOX discs to size waste without clogging, wrapping, and blinding the screen media.
The Freedom Disc screen can easily handle wet, sticky, and coarse materials and is available in both mobile and static configurations.
The BIVITEC flip flow screen uses a unique dual-vibratory principle to transfer high-acceleration forces to the screening surface. Unlike traditional vibrating screens, the BIVITEC evenly delivers vertical and horizontal force to materials fed across its polyurethane screen panels. This results in a steady flow of waste across the screen media. The BIVITEC is an ideal screening solution for sizing plastics, metals, and wood waste.
Request a quote online for more information or call 717-656-2131 to speak with our sales team and learn more about AEI’s screening solutions.