Demolition pulverizers are hydraulic attachments that crush concrete components and expose reinforcing steel. They are used in deconstruction, in construction debris processing and in source-separated sorting of construction materials. In projects where selective deconstruction, low emissions and efficient material separation are required, demolition pulverizers complement other tools such as concrete demolition shear or hydraulic wedge splitter from Darda GmbH. Depending on the task, construction logistics decide whether pulverizing, cutting, splitting or shear work enables the best workflow.
Definition: What is meant by a demolition pulverizer
A demolition pulverizer (also concrete pulverizer or pulverizer shear) is a hydraulic attachment that crushes concrete components, pulverizes them into manageable aggregate and exposes embedded reinforcement. Technically, it is a shear with massive pulverizing jaws, toothed breaker plates and integrated cutting inserts for rebar. A distinction is made between primary pulverizers for direct demolition on the structure and secondary pulverizers for subsequent processing on the ground. The goal is mechanical size reduction with the lowest possible vibration and a clean separation of material fractions for recycling and disposal.
Design, operating principle and types
Demolition pulverizers consist of a shear body with a moving and a fixed jaw, reinforced pulverizing teeth, side wear protection plates, and one or more hydraulic cylinders. An optional 360° continuous rotator increases placement precision. The operating principle is based on high surface pressure and shear loading: concrete is broken between the teeth; reinforcement is cut with inserts or exposed.
Primary vs. secondary pulverizers
- Primary pulverizers: robust jaw design and larger jaw opening for direct attack on walls, slabs and foundations. They combine gripping, breaking and initial sizing.
- Secondary pulverizers: optimized breaker plates for the rapid reduction of already demolished elements on the ground; focus on throughput and rebar exposure.
Construction features
- Crushing teeth and bars with replaceable wear parts to match concrete quality and target particle size.
- Cutting inserts for reinforcement with a defined cutting gap to protect the hydraulics.
- Hydraulics with pressure and flow requirements suited to the carrier class; optional speed valves for short cycle times.
- Rotator for positioning in confined areas; torque matched to component thickness.
Areas of application and typical tasks
Demolition pulverizers are used in various deconstruction and material processing scenarios. They bridge the gap between coarse demolition and fine processing and reduce transport and disposal costs by turning concrete into usable recycled aggregate directly on site.
Concrete demolition and specialized deconstruction
- Crushing of walls, columns, foundations and slabs with low vibration.
- Exposing and separating reinforcing steel for source-separated disposal.
- Preparation for mobile crushing plants by achieving suitable piece size.
Strip-out and cutting
- Processing concrete fragments after detaching add-ons and utilities.
- Combination with concrete demolition shear for precise openings, door and window breakthroughs, and low-emission interior demolition.
Rock demolition and tunneling
- In hard rock, pulverizers are only of limited use. Here, hydraulic wedge splitter or rock wedge splitter with controlled splitting action are suitable, as are hydraulic rock and concrete splitters.
Natural stone extraction
- For natural stone, splitting is preferred over pulverizing. However, pulverizers can efficiently break up concrete foundations, pedestals and secondary installations around quarries.
Special applications
- Selective deconstruction in sensitive areas with requirements for low vibration, dust and noise emissions.
- Processing contaminated concrete in compliance with regulatory requirements; separation of fractions facilitates further treatment.
Comparison and interaction with concrete demolition shears and hydraulic wedge splitters
Whether pulverizing, shear work or splitting—the decision depends on component geometry, reinforcement content, accessibility and emission requirements. Concrete demolition shear enables precise interventions with high control and is particularly suitable indoors and for selective deconstruction. Hydraulic wedge splitter excels when vibrations must be minimal or massive elements need to be opened in a controlled, low-noise manner. Demolition pulverizers show their strength when large volumes of concrete must be quickly reduced to manageable material and reinforcement exposed. In practice, the methods often complement one another: shear for loosening, pulverizer for size reduction, splitter for controlled separation cuts.
Selection criteria, sizing and performance data
Proper sizing improves throughput, safety and cost-effectiveness. Relevant parameters and boundary conditions:
- Carrier: excavator weight and boom geometry must provide load capacity, hydraulic pressure and oil flow.
- Jaw opening and depth: matched to component thickness; jaw width influences gripping behavior on slabs and edges.
- Crushing force and distribution: force peaks at the teeth are critical for high-strength concretes.
- Cycle time: fast open/close cycles increase throughput in secondary demolition.
- Rotational torque: important for precise placement in narrow shafts and on vertical members.
- Wear protection: replaceable teeth, blades and armor make it easy to adapt to material and project duration.
- Hydraulic interfaces: matching operating pressure, return line and flow rate; for handheld solutions, hydraulic power units also supply other tools such as concrete demolition shears or multi cutters.
Work methodology and process chain in deconstruction
A structured approach minimizes emissions and increases material quality for recycling.
- Preparation: survey components, reinforcement content and concrete quality; define emission control measures.
- Primary demolition: detaching components with concrete demolition shear or combination shears; for massive elements, controlled splitting if necessary.
- Secondary pulverizing: reducing detached elements, exposing reinforcement, achieving a suitable particle size.
- Sorting: separate handling of concrete, reinforcing steel and embedded parts; use steel shears for larger steel cross-sections.
- Haulage and recovery: feed recycled concrete; bundle steel fractions for reuse.
Selective deconstruction in urban environments
In inhabited areas, low vibration, dust binding and noise reduction take priority. Here, pulverizers are often operated with water-based dust suppression. In confined access, compact tools such as concrete demolition shear in combination with compact hydraulic power units are used.
Safety, emissions and protective measures
Safe work requires careful planning, trained personnel and appropriate protective measures. Notes of a general nature:
- Define the hazard zone: consider falling parts, snap-back of reinforcement and ejected fragments.
- Dust and noise: water mist systems, shielding and suitable hearing protection; vibration management depending on the surroundings.
- Carrier stability: account for load cases from rotator movements and eccentric gripping.
- Hydraulic safety: depressurize, hose protection, regular visual inspection; avoid hot, pressurized components.
- Component knowledge: prestressed or high-strength material requires an adapted approach and possibly alternative methods.
Resource efficiency, recycling and construction logistics
By exposing reinforcement and reducing concrete size, fractions are provided source-separated. This lowers disposal costs, simplifies transport and improves the carbon footprint (CO₂ balance). Demolition pulverizers thus contribute to the circular use of mineral construction materials; combining them with concrete demolition shear or hydraulic wedge splitter enables low-emission work in sensitive environments.
Maintenance and operation
Regular care increases service life and secures performance.
- Inspect wear parts and rotate or replace in good time (teeth, blades, protection plates).
- Lubricate pins and bearings; check play and adjust per manufacturer specifications.
- Check hydraulics: leaks, filter condition, oil quality, pressure settings.
- Service the rotator: inspect slew ring bearing, rotary union and bolted connections.
- Documentation: record maintenance intervals, load logs and visual inspections.
Limits, alternatives and complementary tools
Demolition pulverizers reach their limits with extremely heavily reinforced or prestressed members, high-strength concrete and thick steel cross-sections. In such cases, other tools are suitable depending on the task:
- Concrete demolition shear for precise opening, controlled removal and low-emission interior demolition.
- Hydraulic wedge splitter as well as rock wedge splitter for low-vibration work in massive components or rock.
- Steel shears for large steel profiles and rebar bundles; multi cutters and combination shears for mixed materials.
- Tank cutter for the safe dismantling of tanks and hollow bodies in deconstruction.
- Hydraulic power pack as the energy source for compact, handheld tools in tight access.