Crushing methods are the technological foundation of demolition, deconstruction and the extraction of mineral raw materials. In practice, the methods range from the controlled splitting of massive structural elements through the breaking and crushing of concrete to the precise cutting and shearing of steel and composite components. In the interplay of tool, carrier machine and hydraulics, a variety of low-emission, low-vibration solutions arise for concrete demolition and special demolition, building gutting and cutting, rock breakout and tunnel construction, natural stone extraction as well as special operations. Products such as hydraulic rock and concrete splitters, concrete demolition shears, combination shears, rock wedge splitters, multi cutters, steel shears, tank cutters and high-performance hydraulic power packs constitute the central equipment level—always adapted to the material, component geometry and environmental requirements.
Definition: What is meant by crushing methods
Crushing methods include all mechanical methods used to deliberately convert solid materials such as concrete, reinforced concrete, masonry, natural stone or steel into smaller units. The goal is a size, shape and purity by fraction that enable haulage, recycling or further processing. Technically this is achieved through splitting, breaking, crushing, cutting or shearing; the methods are often combined, for example when concrete demolition shears break concrete and shear off rebar. Depending on the application, this selectively separates components, releases massive blocks in a controlled manner or processes material into clean fractions.
Basic principles and mechanisms of crushing
Crushing is physically based on stress states in the material. The key is how compressive, tensile, bending and shear stresses are introduced to initiate microcracks and propagate them in a controlled way. Typical methods and tools arise from this:
- Splitting (wedge principle, tension-compression): Hydraulically driven wedges or cylinders load the material in tension across the component plane until it opens. Typical tools: rock and concrete splitters, rock wedge splitters. Application for massive foundations, rock and natural stone blocks.
- Breaking/crushing (compression, bending): Pressing jaws shatter concrete, create cracks and release aggregates from the cement matrix. Typical tools: concrete demolition shears; with combined jaw geometries also hydraulic demolition shear.
- Cutting/shearing (shear): Cutting blades separate ductile material such as reinforcing steel, sections or sheet metal. Typical tools: steel shears, multi cutters, tank cutters; concrete demolition shears with integrated shear function.
- Combined methods: Tools that combine breaking and cutting reduce component thickness and then separate reinforcement—a common approach in selective deconstruction.
Method selection: material, component and environment
The choice of the right crushing method is guided by material behavior, component geometry, accessibility and environmental requirements. Careful tuning avoids oversizing and minimizes emissions.
Material behavior and reinforcement ratio
Brittle materials such as concrete or natural stone can be split or broken efficiently. As the reinforcement ratio increases, shear performance becomes more important—concrete demolition shears with suitable blade geometry or separate steel shears cut the reinforcement. For pure steel or sheet applications, multi cutters or tank cutters are used.
Component geometry, thickness and support
Massive components with sufficient edge distance are predestined for rock and concrete splitters as well as rock wedge splitters. Slabs, walls and ceilings are often divided into fields and pre-broken with concrete demolition shears. Support and load relief influence the crack path; temporary shoring and cut paths ensure controlled fracture patterns.
Accessibility and carrier machine
In confined buildings or sensitive areas, compact, handheld tools with hydraulic power pack are advantageous. Outdoors or on massive structures, attachment tools are used on the carrier machine. Hose line lengths, quick coupling and control comfort determine handling.
Emissions, vibrations and requirements
Where vibrations, dust or noise must be minimized (hospitals, laboratory areas, listed buildings), splitting methods and quiet shears offer advantages. Cut path and force metering are crucial to avoid crack propagation and secondary damage.
Crushing methods in application areas
Concrete demolition and special demolition
Combined methods dominate here. Concrete demolition shears pre-break components, remove edges and reduce cross-sections. Reinforcement is then separated with integrated blades or separate steel shears. For massive foundations, splitting with rock and concrete splitters can predefine fragment size to adapt lifting devices and transport logistics.
- Procedure: field layout – pre-breaking – rebar cutting – sorting (mineral/metal) – haulage logistics.
- Benefits: controlled crack paths, low vibration levels, good sortability of fractions.
Building gutting and cutting
Within the building structure, multi cutters and tank cutters separate utility lines, beams, tanks and sheet metal. Concrete demolition shears remove residual concrete or mortar bridges at component connections. Size reduction often takes place in small, manageable elements to use elevators or narrow escape routes.
Rock breakout and tunnel construction
In loose rock, classic excavator operations are common; in hard rock, rock and concrete splitters and rock wedge splitters provide a low-vibration alternative. Split wedges inserted into boreholes generate targeted tensile stresses and lead to predictable fracture planes—useful for breakouts in sensitive zones, near existing structures or where blasting options are limited, an approach used throughout rock demolition and tunnel construction.
Natural stone extraction
The extraction of dimension stone requires gentle methods. Splitting technology with rock wedge splitters makes it possible to release blocks along natural joints and preserve surface quality. The low introduction of microcracks supports further processing and value creation.
Special operations
In areas with increased fire or explosion risk, in densely populated urban quarters or in facilities with sensitive infrastructure, controlled, low-vibration crushing methods are essential. Hydraulically driven splitters, concrete demolition shears, tank cutters and steel shears work with few sparks and can be controlled precisely—an advantage for safe workflows and neighborhood protection.
Process flow and best practices
- Analysis: Record material, reinforcement, thickness, load transfer, utility line routing and boundary conditions.
- Method selection: Define splitting, breaking, cutting or combinations; size tools and hydraulic power packs.
- Field and cut planning: Define grid, drilling patterns, split points and shear lines; plan shoring and safety.
- Execution: Introduce force in a controlled manner, monitor crack growth, steer fragment sizes, cut rebar in a targeted way.
- Sorting: Provide mineral material, steel and special substances separately; optimize routes for haulage logistics.
- Documentation: Log procedure, emissions, material quantities and safety steps.
Hydraulic power packs: power supply and control
Hydraulic power packs deliver the required flow rate and pressure for splitters, shears and cutters. A proper design of compact hydraulic power units ensures repeatable cycles and consistent tool performance. The decisive factors are:
- Power matching between power pack, hydraulic hose lines and tool (pressure/flow rate).
- Controllability: fine metering for controlled crack propagation and clean cut edges.
- Interfaces: quick coupling, pressure relief, emergency stop and pressure-rated gauges enable safe operation.
- Energy source and environment: choose between electric- or combustion-driven power packs according to site, environmental requirements and ventilation conditions.
Safety, health and environment
Safe work is an integral part of every crushing method. In general, the applicable occupational safety rules and construction site requirements apply; this does not replace project-specific advice.
- Observe personal protective equipment, barriers, load and tip-over protection.
- Hydraulic safety: relieve pressure, avoid leaks, inspect hoses regularly.
- Emissions control: dust suppression, noise reduction measures, low-spark methods, orderly disposal of residual materials.
- Observe structural stability and crack paths; choose cut and split sequences to prevent unintended breakage.
Result quality, sortability and recycling
Good crushing shows in defined fragment sizes, clear fracture planes and cleanly separated reinforcement. Concrete demolition shears deliver rough fracture surfaces suitable for follow-up work; rock and concrete splitters create flat separation planes that make handling large pieces easier. Clean separation by fraction improves the recycling rate and reduces transport and disposal costs.
Maintenance, wear and operation
- Tool care: adjust/replace blades, check jaws for wear, inspect wedges.
- Hydraulics: check oil condition, filters and seals; keep couplings clean.
- Operation: run cycles evenly, avoid overload, apply the tool only at the intended angle.
- Documented inspections increase availability and process safety.
Typical error sources and solutions
- Fields/fragments too large: reduce the grid, add additional split points or pre-breaks.
- Undesired cracks: increase force step by step, shore, maintain edge distances, adjust drilling patterns.
- Insufficient cut quality: check blade condition, match hydraulic pressure/flow rate.
- Time loss due to tool changes: plan combined approaches (e.g., breaking with a concrete demolition shear and immediately shearing the rebar).
Terminology within crushing
Splitting targets tearing open brittle materials through tensile stresses—typical for rock and concrete splitters and rock wedge splitters. Breaking uses compression and bending for the fragmentation of concrete, for which concrete demolition shears are the standard tool. Cutting/shearing separates ductile materials and reinforcement with blade geometries as used by steel shears, multi cutters and tank cutters. In practice these methods are combined to work selectively, with low emissions and economically.