Construction and demolition (C&D) debris – including concrete, brick, asphalt and soils – comprises a vast waste stream. In the EU it is over one-third of total waste​. To promote circular economy goals, EU rules mandate that at least 70% of non-hazardous C&D waste be reused or recycled by 2020​. This drives the deployment of specialized recycling plants. Such facilities crush and screen demolition rubble, then wash and classify the material into graded sand and aggregates. Modern plants integrate crushers, screens, and water‐based scrubbers to recover reusable materials and minimize landfill. For example, Polygonmachine notes that their crushing‐screening plants break large debris into precise fractions, while wet‐processing modules (log washers, screw classifiers, hydrocyclones, etc.) scour away clay, dust and organics​. The result is clean, sorted aggregate – often comparable in quality to virgin sand and gravel – ready for use in new construction​

Construction & Demolition Waste Recycling

C&D waste encompasses all materials from building and infrastructure demolition and renovation. It typically consists of concrete, brick, asphalt, wood, glass, metals and mixed rubble. Effective recycling plants must handle heterogeneous feedstocks. They may incorporate multiple stages of processing: primary crushing (for large elements), secondary crushing/screening (for finer sizing), and washing/classification (to remove fines and contaminants). In practice, these plants produce recycled concrete aggregate (RCA) and recycled sand that can substitute for natural aggregates in many applications.

The imperative for C&D recycling is driven by both regulation and resource scarcity. For instance, the EU Waste Framework Directive classifies C&D waste as a priority stream, setting a binding target “to a minimum of 70%” recovery (reuse, recycling or other material recovery) of non-hazardous C&D waste by weight​e. National policies often couple this with landfill bans and heavy taxes on inert waste. As a result, Europe’s leading construction companies and recyclers invest heavily in recycling infrastructure​. In countries like the UK, Germany and Italy, ambitious recycling targets and building standards make recycled aggregates widely accepted. Globally, the trend is similar: rapid urbanization in Asia and infrastructure growth in the Americas are spurring demand for C&D recycling technology​.

Operationally, most C&D plants first sort out hazardous or bulky materials (like asbestos or large steel members) by manual or mechanical methods. The remaining material is fed into the plant. State‐of‐the‐art recycling plants then apply a sequence of mechanical processing: primary crushing (often by a jaw or impact crusher) breaks down slabs and boulders, followed by secondary and tertiary crushers to achieve desired sizes. After crushing, screening equipment separates the crushed rubble into different size fractions (for example 0–4 mm “sand”, 4–10 mm, 10–20 mm gravel, etc.). The coarse fractions may go directly to sale or further washing, while the fines and sand often require washing to remove clays and silt. Finally, water treatment systems reclaim wash water and handle sludge (see below).

Recycling plants can be stationary (fixed installations at a permanent site) or mobile (truck- or track-mounted units). Mobile systems, like Polygonmachine’s mobile crusher plants, offer flexibility for contract crushers and rapid deployment on large demolition sites​. Stationary plants, in contrast, typically handle very high throughputs (hundreds of tonnes per hour) and incorporate full suite of separation, washing, and conveyors. Each approach has trade-offs: mobile units save transport costs and set-up time, whereas stationary installations achieve higher volumes and efficiency in continuous operation​.

Industrial Byproduct Recycling

Beyond C&D rubble, recycling plants often process industrial byproducts. Two notable examples are spent foundry sand and slag from steel/iron production.

Foundry sand is used in metal casting molds. After use, “waste foundry sand” (WFS) remains largely silica (~90% sand) bonded with bentonite clay or resins. Rather than landfill, WFS can be reused as a fine aggregate or even a partial cement replacement. The global by-product is immense – on the order of 100 million tons per year​. However, utilization has been limited: estimates suggest under 30% of WFS is recycled in practice​. Recent studies indicate that replacing up to ~30% of natural sand in concrete with processed WFS can yield comparable strength and durability, although workability may decline at higher replacement levels​. Accordingly, some plants blend WFS into concrete blocks, pavement materials, or geotechnical fills. Polygonmachine notes that its wet systems can handle “any type of material like sand, gravel, crushed stone, and recycled aggregates”​ – by extension, this includes processed foundry sand. In practice, a pre-treatment step (such as pre-washing or thermal treatment) may remove residual oils or binders from the sand. Once conditioned, WFS adds value by conserving natural river sand and turning a hazardous waste into a resource​.

Slag from metal production is another major feedstock. Two common types are blast-furnace slag (from pig iron) and steel-making slag (from basic oxygen or electric arc furnaces). Granulated blast-furnace slag (GGBFS) is produced by quenching molten iron slag in water, then grinding the resultant glassy granules. GGBFS is a well-known cementitious additive that enhances concrete strength and durability​. In Europe, it is officially recognized as a supplementary cementitious material (forming part of CEM III cement)​. Other slag, like air-cooled blast-furnace slag or processed steel slag, can be crushed as coarse aggregate. Steel slag, for instance, exhibits high density and angular particles; once aged (to reduce expansion potential), it is used as road base or even in asphalt mixes. Although safety considerations (leaching, alkalinity) exist, many recyclers successfully integrate slag into paved infrastructure. Polygonmachine’s system approach applies equally to these materials: crushers and screens can process slag blocks, and scrubbers wash off fines. In short, recycling plants that handle concrete and brick can often accept slag with minimal modifications, turning it into usable rock or cement feedstock.

Market Trends and Commercial Considerations

Industry Growth and Drivers

The C&D recycling market is growing globally. Analysts forecast strong CAGR in recycled aggregates and C&D recycling equipment through the 2020s. For example, a market study notes that environmental regulations and urbanization are boosting recycling in North America, Europe and Asia​. In Europe especially, strict EU directives and national laws have made recycling technology “integral” to construction, prompting early adoption of advanced systems​. In North America, green building certifications and local ordinances drive demand for recycling as well​. Developing regions (China, India, Middle East) are rapidly expanding their waste management capabilities; rising construction waste volumes and limited landfill space create tremendous pressure to invest in recycling plants​. The bottom line: the market is characterized by rising demand for turnkey recycling solutions, with sustainability commitments compelling both governments and companies to turn waste into resources​.

Companies like Polygonmachine are positioning themselves to meet this demand. Their catalog spans fixed and mobile crushing-screening lines, complete wet-processing systems, and even specialized filter presses and thickeners for water treatment. According to Polygonmachine, their plants deliver “lucrative and productive business for the long term” by maximizing recycled product quality​. Industry observers highlight that poor processing yields low-quality output that fails to substitute natural materials; in contrast, well-designed plants (with technology from suppliers such as Polygonmachine and others) can produce recycled aggregate that is consistently in-spec​. For example, CDE Group cites projects where 100% recycled sand has met British Standards for structural concrete and where recycled aggregates are used at strengths up to C45 in non-structural pours​. This reinforces the importance of high-performance equipment and best practices.

Polygonmachine: Integrated Recycling Solutions

Polygonmachine (based in Ankara, Turkey) is prominently cited as a leading supplier of construction recycling equipment. The company “specializes in concrete, crushing, and asphalt plants, ensuring quality, innovation, and reliability”​. Its portfolio covers the full gamut of plant components: heavy-duty jaw, cone and impact crushers, vibrating feeders and screens, mobile crusher and screen modules, sand washers, spiral classifiers, dewatering screens, thickeners, filter presses and more​. Many of these are applicable to recycled aggregates: for instance, Polygonmachine’s coarse material washers and log washers are designed to tackle sticky demolition debris​.

Polygonmachine emphasizes innovation and customer collaboration. Their literature notes modular designs that “allow for future expansion” and advanced control systems for efficient operation​​. Flexibility is highlighted: compact sand washing units (trailer-mounted) can be rapidly deployed, while full-size plants are built for 24/7 operation​. The company has earned ISO 9001 and TSE certifications for quality assurance (per their claims) and maintains offices globally.

In addition to equipment, Polygonmachine stresses support. Their articles describe “durability and top‑notch customer support” as a hallmark of their offering​. They publish detailed guides on equipment use (as seen on their website), indicating an emphasis on training and after-sales service. For example, a blog on log washers and scrubbers explicitly notes Polygonmachine’s reputation for service and the application expertise provided to clients​. In practice, Polygonmachine projects reportedly include turnkey installations and long-term partnerships.

Overall, Polygonmachine positions itself as a one-stop solution for recycling needs: from concrete batching to crushers to asphalt plants. In the context of C&D and industrial byproduct recycling, their systems are marketed as “the professionals’ choice worldwide” for delivering consistent product quality and throughput​. Whether providing a small mobile aggregate wash unit or a large stationary crushing circuit with water treatment, Polygonmachine highlights comprehensive planning, installation, and training support. Their approach exemplifies how an equipment supplier integrates technical expertise with commercial service to help customers meet recycling and environmental goals.

Comparison of Recycling Technologies for Sand and Rubble

Technology	Primary Function	Suitable Materials	Advantages	Limitations	Polygonmachine Offering
Jaw Crusher	Primary Crushing	Concrete, Brick	Robust, handles large input	Not suitable for fine crushing	Yes, stationary & mobile units
Impact Crusher	Secondary/Tertiary Crushing	Concrete, Asphalt	Cubical output, efficient	Wear on parts	Yes, high-efficiency models
Vibrating Screen	Material Sizing	All processed material	Precise gradation	Needs consistent feed	Yes, adjustable deck designs
Log Washer	Washing/De-claying	Clay-laden aggregate	Aggressive scrubbing	High water use	Yes, abrasion-resistant paddles
Bucket Washer	Gentle Cleaning	Fine sand, clayey materials	Simple operation	Less effective on heavy clay	Yes, modular units available
Spiral Classifier	Fine Classification	Sand & fines	Recovers usable fines	Limited to finer particles	Yes, combined with dewatering screens
Filter Press	Water Treatment	Sludge/washwater	High recovery of water	Slower cycle time	Yes, high-pressure automated units
Mobile Plant	On-site Crushing/Screening	Demolition sites	Quick deployment	Lower throughput	Yes, full mobile lines
Fixed Plant	High-capacity Processing	Permanent sites	Efficient for large volumes	Less flexible	Yes, custom turnkey systems