Secondary breakage refers to the targeted follow-up processing of already detached structural elements or rock blocks to reduce them to manageable sizes, expose reinforcement, or adjust geometry. In deconstruction, rock excavation and tunnel construction, this work step directly follows the primary demolition and determines occupational safety, cycle time, noise and vibration levels, as well as recycling quality. Frequently, concrete pulverizers or hydraulic rock and concrete splitters are used, supplied by compact hydraulic power units. Properly planned, secondary breakage enables controlled, low-emission, material-specific fragmentation—from selective concrete demolition to natural stone extraction.
Definition: What is meant by secondary breakage
Secondary breakage is the secondary size reduction or further separation of already detached concrete and masonry elements, steel and mixed composites, or rock and natural stone blocks. The aim is to transfer components into transport- and sorting-capable fractions, expose reinforcing steel, and create the prerequisites for haulage, reuse, or material recycling. In contrast to primary demolition (e.g., cutting, sawing, drilling, blasting), secondary breakage acts locally, in a controlled manner, and is generally low-vibration; typical methods are hydraulic pressing, splitting, cutting and crushing, for example with concrete pulverizers or rock and concrete splitters.
Process, methods and tools in secondary breakage
Secondary breakage follows a simple logic: first the suitable attack point is selected, then the component geometry is assessed with regard to reinforcement, stresses, and support conditions. Subsequently, suitable tools are used to release, split, cut, or crush the components in a controlled way. Hydraulic power packs provide the necessary output, while shears, pulverizers, split cylinders and special devices perform the actual separation work.
Methods and tools at a glance
Depending on material, component thickness, degree of reinforcement and environmental sensitivity, different methods are combined. The most important tool groups in secondary breakage are:
- Concrete pulverizers: For controlled crushing of concrete and masonry and for exposing reinforcement. Advantages include precise placement, low edge damage, and good material separation quality.
- Rock and concrete splitters: Split massive components or rock blocks using wedge-based static forces. The method is low-vibration and suitable for noise-sensitive areas or works near load-bearing structures.
- Rock splitting cylinders: For pinpoint initiation of desired fracture lines in rock or thick concrete; often in combination with predrilled initiation points.
- Combination shears: Combine crushing and cutting functions, helpful when switching between concrete crushing and cutting lighter steel inserts.
- Multi Cutters: For clean cutting of lines, cables, pipes and lighter steels, ideal for type-pure material separation in secondary breakage.
- Steel shears: For load-bearing sections, thick reinforcement bundles or more massive steel components that must be cut after exposure.
- Tank cutters: For controlled sectioning of vessels, tanks, and double-walled hollow bodies during deconstruction, particularly when sparking must be minimized.
- Hydraulic power packs: Provide the required output for mobile pulverizers, shears and splitters; the choice of pressure and flow rate influences force, cycle time and efficiency.
Fields of application and typical workflows
Secondary breakage is established across several industries. The appropriate tools and sequences differ according to building material, boundary conditions and target sizes.
Concrete demolition and special deconstruction
In selective deconstruction, secondary breakage is used to reduce elements step by step, expose reinforcement and separate materials by type. Concrete pulverizers are the central tool here; rock and concrete splitters are used where vibration, noise and dust are particularly critical.
- Component analysis: geometry, support conditions, reinforcement routing, removal direction
- Pre-cutting/pre-drilling of desired fracture lines (if required)
- Secondary breakage with concrete pulverizer or splitter in controlled cycles
- Expose and cut reinforcement using Multi Cutters or steel shears
- Sort by material fractions and load out
Strip-out and cutting
In strip-out, secondary breakage is used to create openings, exploit embrittlement and release embedded items. After sawing or drilling, breaking with the concrete pulverizer often follows to form edges or bring components to transport size.
Rock excavation and tunnel construction
After primary loosening (e.g., blasting or milling), oversize pieces arise that must be reduced for workflow and conveying. Rock splitting cylinders and rock and concrete splitters enable controlled, low-vibration secondary size reduction, even in restricted cross-sections or near sensitive lining elements.
Natural stone extraction
In natural stone extraction, raw blocks are secondarily broken so that usable geometries and smooth fracture surfaces are maintained. Static splitting methods minimize microcracks, benefiting surface quality and downstream processing.
Special applications
In areas with heightened protection requirements—such as hospitals, laboratories, industrial plants or for tanks and vessels—precise, low-vibration secondary breakage is crucial. Tank cutters, Multi Cutters as well as concrete pulverizers and splitters are combined to limit sparking, noise and vibration.
Selection of the appropriate method
The choice of pulverizer, splitter, shear or a combination is based on technical, organizational and environmental criteria:
- Component properties: thickness, compressive strength, aggregates, degree and position of reinforcement
- Accessibility: working space, lifting equipment, visibility, attack points, edges
- Environment: vibration and noise control, dust limits, neighborhood, building statics
- Process goals: target fragment size, type purity, reusability, conveying logistics
- Resources: availability of the hydraulic power pack, tool change times, operator competence
- Safety: fall, crushing and cutting hazards, safe load handling, emergency-stop concepts
Process organization, safety and environment
Secondary breakage significantly influences site logistics and compliance with protection targets. The following have proven effective in practice:
- Occupational safety: Bracing components, protection against falling parts, clear exclusion zones, safe hose routing, regular functional checks of the hydraulics.
- Vibration and noise control: Prefer static splitting methods or precise crushing with concrete pulverizers; choose stroke rate and pressure moderately, set contact points according to plan.
- Dust and water management: Wet in a targeted manner, retain and dispose of water; prioritize low-emission work sequences.
- Material separation: Pure fractions through early exposure and cutting of reinforcement with Multi Cutters or steel shears; short routes to sorting.
- Documentation: Recorded masses, fractions, transport routes and reuse rates secure quality and verification.
Sizing in secondary breakage: practical guidelines
The target size should be aligned with transport equipment, grapple width, container size and downstream crushing/screening stages. Uniform piece sizes shorten cycle times and facilitate sorting. For heavily reinforced components, it is often efficient to first crush the concrete with the concrete pulverizer, expose the reinforcement, and only then cut it with steel shears or Multi Cutters. In noise-sensitive or structurally critical situations, splitting with rock and concrete splitters is suitable to trigger load redistribution in a controlled way with minimal edge cracking.
Example workflow in building deconstruction
- Pre-survey: component assessment, reinforcement analysis, boundary conditions (noise, vibration, dust)
- Primary separation: sawing/drilling or mechanical separation to produce manageable segments
- Secondary breakage: crushing with concrete pulverizers or splitting with rock and concrete splitters, adjusted to the target fragment size
- Expose and cut: reinforcement with Multi Cutters or steel shears; separate pipes/cables
- Sorting: provide concrete, steel, masonry, lines and special substances separately
- Loading and haulage: adapt piece sizes to grapple/container; keep routes short
- Documentation: record quantities, fractions, and disposal or recycling routes
Quality and recyclability
High-quality secondary breakage creates clean edges, defined piece sizes and cleanly exposed reinforcement. This improves the recyclability of concrete rubble as recycled construction material and shortens process times in downstream crushing and screening plants. In natural stone extraction, careful splitting yields low-crack blocks, simplifying further processing. The appropriate combination of concrete pulverizers, rock and concrete splitters and suitable shears, supplied by matching hydraulic power packs, enables efficient, safe and environmentally compatible secondary breakage—in concrete demolition, in rock excavation and in tunnel construction alike.