Concrete & Asphalt Recycling Crushing Solutions
Construction and Demolition (C&D) waste - including reinforced concrete slabs, asphalt pavement millings, brick rubble, and mixed demolition debris - represents one of the most mechanically demanding material streams a crusher can process. Unlike virgin quarry stone, recycled concrete contains embedded rebar, wire mesh, and prestressed cable; recycled asphalt carries residual bitumen that clogs crushing chambers and accelerates thermal wear. According to the U.S. EPA and European Environment Agency, C&D waste accounts for over 30% of total solid waste generated in industrialized countries, and the global recycled aggregate market is expanding at a steady pace driven by green building standards, landfill restrictions, and circular economy legislation.
The combination of abrasion, impact shock, and metallic contamination in recycled concrete and asphalt imposes unique stresses on crusher wear parts - stresses that standard quarry-grade liners are simply not designed to handle. DUMA has engineered its impact crusher blow bars, jaw plates, cheek plates, and impact liner plates specifically to survive these conditions, giving C&D recycling operators longer change intervals, lower downtime, and a demonstrably reduced cost per processed ton.
Why Concrete & Asphalt Recycling Is Hard on Wear Parts
Recycled concrete and asphalt present a distinct wear profile compared to natural rock:
Reinforcing steel contamination
Even after pre-screening and magnetic separation, residual rebar fragments and wire mesh reach the crusher. These metal inclusions cause sudden impact peaks - far exceeding the design loads of conventional manganese steel liners - leading to chipping, cracking, and premature fatigue failure of wear surfaces.
Silica-rich aggregate cores
The gravel and crushed stone within concrete typically exhibits Mohs hardness of 6-7, producing abrasive wear comparable to hard limestone or sandstone. Over successive load cycles, this steadily erodes liner surfaces regardless of impact events.
Bituminous adhesion in asphalt recycling
Reclaimed asphalt pavement (RAP) contains 4-7% residual binder by mass (ASTM D6307). At elevated processing temperatures, this binder softens, coats wear surfaces, and causes material buildup that alters crushing geometry and generates localized hot spots - accelerating both thermal fatigue and adhesive wear.
Mixed and inconsistent feed
C&D waste varies enormously in composition from one job site to the next. A liner optimized purely for impact resistance may wear rapidly under abrasion-heavy loads; one optimized purely for hardness may crack under rebar impact. The ideal solution balances both.
Recommended Crusher Configuration for Concrete & Asphalt Recycling
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Primary Stage - Jaw Crusher
A jaw crusher is the standard choice for primary size reduction of demolition rubble and concrete blocks. Its wide jaw opening accepts oversized feed directly from demolition excavators or hydraulic shears, and its relatively slow, compressive action is tolerant of occasional rebar fragments without catastrophic damage to the crushing chamber.
For this stage, the key wear consumables are jaw plates (fixed and swing) and cheek plates (side liner plates). The high silica content of aggregate within demolished concrete produces pronounced abrasion across the full plate face, while steel inclusions create localized impact points that can cause surface spalling on standard manganese liners. DUMA recommends jaw plates manufactured from high-manganese steel with optimized work-hardening profiles, or composite jaw plates with high-chromium surface layers for sites processing consistently hard or high-steel-content demolition feeds. Cheek plates should be replaced as a pair at each scheduled jaw plate change to maintain consistent chamber geometry and prevent uneven wear migration.
Recommended DUMA Products for Primary Jaw Crushing:
Jaw Crusher Liners
Jaw Crusher Parts – Fixed Jaw Plate
Cheek Plates and Side Liner Plates
Secondary Stage - Impact Crusher (Primary Recommendation for C&D Recycling)
The impact crusher - specifically the horizontal shaft impactor (HSI) - is the dominant machine in dedicated concrete and asphalt recycling lines worldwide. Its open rotor design, wide gap settings, and ability to produce cubic, well-shaped particles make it ideal for generating recycled concrete aggregate (RCA) and reclaimed asphalt pavement (RAP) products that meet EN 933-1, ASTM C33, or local road-base specifications.
In an HSI, the primary wear consumables are blow bars (the rotor-mounted impact elements) and impact plates / apron liners (the chamber liners against which material is thrown). These are the highest-cost, highest-frequency consumables on any recycling line and represent the single greatest lever for reducing total operating cost.
Blow bar material selection is critical. The industry has converged on the following guidance (consistent with recommendations from major crusher OEMs and the European Aggregates Association):
High-chromium cast iron (Cr26–Cr30)
Optimal for clean or lightly contaminated concrete and asphalt where abrasion dominates. Offers hardness in the HRC 58–64 range, delivering 2–3× the abrasion life of standard austenitic manganese steel in silica-rich feeds. Not recommended where significant rebar contamination persists past magnetic separation, as high chrome is brittle under severe shock loading.
Martensitic steel blow bars
A balanced option offering good impact toughness alongside moderate hardness (HRC 45–52). Preferred on lines where magnetic separation is incomplete or feed composition is variable. Provides a more predictable, failure-safe wear mode (progressive surface wear rather than sudden fracture).
High-chrome + ceramic composite blow bars
The premium solution for high-throughput, high-abrasion applications. Ceramic inserts (Al₂O₃ or ZrO₂) embedded in a high-chrome matrix deliver maximum wear resistance at the impact face. Appropriate for clean concrete recycling or asphalt-only lines where throughput economics justify the higher unit cost.
Impact plates should be selected in matching grades to the blow bars to maintain balanced wear rates across the crushing chamber and avoid uneven load distribution on the rotor.
Recommended DUMA Products for Impact Crushing Stage:
● Impact Crusher Wear Parts (Impact Plate)
● Blow Bars for Impact Crushers
Two-Stage Configuration - Jaw + Impact Crusher (Most Common Layout)
The jaw crusher + HSI impact crusher two-stage configuration is the industry-standard layout for urban and highway demolition recycling projects. The jaw crusher handles primary size reduction and provides a relatively uniform feed (typically 80–150 mm) to the impact crusher, which then delivers final product in the 0–40 mm or 0–80 mm fractions required for road base, backfill, or concrete aggregate applications.
This configuration is particularly well-suited to mobile and semi-mobile recycling plants that process material directly on demolition sites, where simplicity, rapid relocation, and minimal infrastructure requirements are priorities.
In terms of wear part management for this layout: jaw plate life and blow bar life rarely align perfectly, so it is good practice to monitor both independently and maintain a stock of both consumable types on-site. DUMA can supply jaw plates and blow bars as a paired package with matched alloy grades, simplifying procurement and ensuring compatible wear rates across the full crushing circuit.
Key Wear Part Selection Principles for Recycling Applications
The following principles are widely recognized across the C&D recycling industry and are reflected in DUMA's product recommendations:
Prioritize impact toughness in the primary stage
Jaw plates that crack under sudden steel impacts create emergency downtime and potential structural damage to the crusher. High-manganese steel's work-hardening behavior provides a natural safeguard: the surface hardens progressively under impact rather than shattering.
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Match blow bar grade to contamination level
The residual metal content in your feed - after magnetic separation - is the single most important factor in blow bar selection. Higher steel content = shift toward tougher, more ductile alloy grades, even at some cost to wear life per change. The most expensive blow bar is the one that fractures mid-campaign and causes rotor imbalance.
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Replace impact plates and blow bars as a set where possible
Mismatched wear levels between the rotor and the chamber liners alter material trajectory, reduce crushing efficiency, and accelerate uneven wear on the heavier component.
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Account for asphalt's thermal and adhesive behavior
On RAP-heavy lines, schedule wear part inspections more frequently during hot weather operations. Bitumen buildup on impact plates is best managed by brief shutdown-and-clean cycles rather than running to failure - a practice endorsed by both Wirtgen Group and Metso Outotec in their respective recycling application guides.
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Factor in the full cost per ton, not unit part price
A blow bar with 20% higher unit cost but 50% longer service life reduces both part cost and change-labor cost per ton of output - the metric that ultimately determines recycling line profitability.
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Why Choose DUMA for Your C&D Recycling Wear Parts
As a direct-operated manufacturing facility with a 42,000 m² production base in Jiangxi, China, DUMA produces its crusher wear parts entirely in-house - from alloy formulation and casting through heat treatment, dimensional inspection, and packaging. This end-to-end control allows us to offer:
Custom alloy grades matched to your specific feed material and crusher model, rather than off-the-shelf compromises
OEM-compatible dimensions for all major impact crusher brands including Metso/Nordberg NP series, Sandvik CI/CV series, Terex Finlay, and Kleemann MOBIREX, as well as jaw crusher compatibility with Sandvik CJ/JM series, Metso C series, and others
ISO 9001:2015 certified quality management, with full material traceability and hardness certification for every batch
Export experience across 30+ countries, including North America, Australia, Germany, and the UK - markets with stringent recycled aggregate quality standards that demand consistent, reliable wear part performance
Flexible order quantities - whether you operate a single mobile recycling plant or a high-volume stationary C&D processing facility, DUMA can accommodate your volume with competitive lead times
Frequently Asked Questions
Q: Can DUMA supply blow bars for mobile recycling crushers (e.g., Terex Finlay I-120, Kleemann MOBIREX MR 110)?
A: Yes. DUMA produces blow bars compatible with all major mobile impact crusher models used in the C&D recycling sector. Please provide your machine make, model, and rotor dimensions when inquiring, and our technical team will confirm the correct specification.
Q: What blow bar material do you recommend for recycling mixed demolition concrete with incomplete rebar removal?
A: For feeds with confirmed residual metal contamination, we recommend martensitic steel blow bars as a starting point, with high-chrome options available once metal contamination is reduced to low levels through improved pre-screening and magnetic separation upstream.
Q: Do you offer wear part kits (blow bars + impact plates together)?
A: Yes. We can supply matched sets with consistent alloy grades to ensure balanced wear across your crushing chamber. Contact us to discuss your machine model and campaign length requirements.
Q: How do I reduce blow bar consumption when processing hot asphalt RAP?
A: Bituminous adhesion increases the effective load on blow bars and can mask actual wear until a sudden failure occurs. We recommend scheduling visual inspections every 50–80 operating hours on RAP-heavy lines, and informing our technical team of your average bitumen content so we can fine-tune the alloy recommendation accordingly.
The above reflects general best-practice guidance for concrete and asphalt recycling crushing configurations. Actual wear part selection should be optimized for your specific feed composition, throughput target, and crusher model. In C&D recycling, the right wear part specification directly determines your cost per ton of recycled aggregate - it is worth getting right from the outset.
Contact DUMA's technical team for a wear parts recommendation tailored to your recycling line →