The hydraulic splitter method describes a friction-locked technique in which pressure is introduced via hydraulic rams, wedge or spreading elements into concrete, masonry, or rock in order to create controlled cracks, detach components, or open structures. In deconstruction and natural stone extraction practice, the method is primarily chosen when low-noise, low-vibration, and well-controlled processes are required. In combination with equipment from Darda GmbH—especially with stone and concrete splitting devices, rock splitting cylinders, and concrete demolition shear—the hydraulic splitter method can be adapted to different materials and boundary conditions, from selective concrete demolition through special demolition to rock breakout.
Definition: What is meant by the hydraulic splitter method
The hydraulic splitter method is a hydraulic pressure method in which a ram (cylinder, wedge, or spreading element) introduces its force centrally or over an area into a component or rock. The objective is targeted crack growth along weaker planes or predefined separation lines. The introduction of compressive force takes place either internally (e.g., in a borehole via splitting cylinders with wedge action) or externally (e.g., between two component surfaces by bracing and pushing apart). It is characterized by high forces with comparatively small component movement and good controllability of the crack path through the drill pattern, load control, and support geometry.
Basic principle and classification within demolition and splitting technology
The basic principle relies on the fact that brittle mineral materials such as concrete and natural stone have high compressive strength but lower tensile and splitting tensile strength. The ram locally generates compressive stresses and resulting tensile stresses transverse to the load line. In boreholes, this action is amplified via a wedge with counter-wedges; externally, plane-parallel pressure plates provide force transmission. The hydraulic splitter method complements mechanical separation processes such as concrete demolition shear, sawing, and cutting and bridges the gap between purely chip-forming processes and energy-intensive methods. In practice it is assigned to the following areas of application: concrete demolition and special demolition, gutting and cutting (in combination with pre-separations), rock breakout and tunnel construction, natural stone extraction, as well as special use, for example with confined access or sensitive environments.
Variants of the hydraulic splitter method
Internal jacking in the borehole (splitting principle)
With internal jacking, boreholes are prepared in advance. A hydraulically driven wedge spreads counter-wedges and transfers high forces radially into the component. This creates controlled splitting lines. Stone and concrete splitting devices and rock splitting cylinders are typical implementations of this principle in concrete demolition, rock removal, and natural stone extraction.
External jacking between components
Here, hydraulic cylinders act as compression struts between two opposing faces. The method is suitable for opening joints, relieving bonded interfaces, or detaching components. It is often combined with preceding saw cuts to define the crack path.
Combination with concrete demolition shear
Concrete demolition shear generates local compressive and crushing stresses, cuts reinforcement, and reduces cross-sections. The hydraulic splitter method can be applied before or after: pre-breaking by jacking facilitates the work of the shear; alternatively, core areas remaining after shearing are separated using splitting cylinders. This combination is common in special demolition and during building gutting.
Use in natural stone extraction
In natural stone quarries, splitting lines are predefined via drill patterns. The jacking sequence produces clean fracture faces with reduced material loss. The method is low in noise and vibration and thus suitable for sensitive locations.
Practical sequence: from drill pattern to separation
- Analysis of material and structure: concrete strength class, reinforcement ratio, rock jointing pattern, edge distances, supports.
- Definition of the separation line and drill pattern: diameter, depth, axis spacing, edge distances.
- Preparatory measures: relief cuts, shoring, safety and dust protection concept.
- Positioning the rams: inserting rock splitting cylinders into the borehole or placing external hydraulic rams.
- Load application: stepwise pressure increase, monitoring crack formation, noise development, and deformation.
- Follow-up and sequence: relocating the rams along the line until separation; if necessary, combine with concrete demolition shear for biting off or secondary breakage.
- Securing and disposal: removal, intermediate storage, separation of concrete and reinforcement, documentation.
Technical parameters and influencing factors
- Borehole parameters: diameter and depth influence wedge transmission and thus splitting force.
- Material: compressive, tensile, and splitting tensile strength, grain structure, moisture, and temperature change crack initiation.
- Reinforcement: density and bar diameter can deflect crack paths; pre-separations or subsequent shearing and cutting help.
- Edge distances: distances that are too small lead to uncontrolled spalling; sufficient bearing is essential.
- Hydraulic pressure and flow rate: they determine the speed and maximum force of jacking.
- Sequencing: uniform progress prevents restraint stresses and minimizes secondary cracks.
Advantages, limitations, and alternatives
Advantages
- Low-noise and low-vibration, suitable for sensitive areas such as hospitals or heritage-adjacent zones.
- High controllability of the crack path through the drill pattern and pressure stages.
- Minimal sparking, reduced risk in ATEX zones when appropriately planned.
Limitations
- Heavy reinforcement requires additional separation steps (cutting, shearing).
- Drilling and setup effort; the method is of limited use for very thin components.
- In heterogeneous composite cross-sections, the crack path may deviate.
Alternatives and complements
- Concrete demolition shear for biting off and crushing, particularly with reinforced concrete.
- Combination shears, multi cutters, and steel shear for metallic inserts and sections.
- Sawing and cutting for defined pre-separation and edge quality.
- Cutting torch in special metallic scenarios outside concrete.
Safety, planning, and accepted practice
Work with hydraulic pressure requires careful planning. Structural issues, load paths, and retention concepts must be clarified in advance. Personal protective equipment, safety distances, shielding against spalling, and safe hose routing are mandatory parts of the work concept. In areas with potential explosion hazards, only suitable work equipment and procedures with low ignition sources are to be used. The information provided is generally formulated and does not replace project-specific professional planning.
Selecting the right equipment
The selection is based on component thickness, reinforcement content, required edge quality, and accessibility. For massive components or rock with a clear separation line, stone and concrete splitting devices with high wedge transmission are proven. Where reinforcement must be cut, concrete demolition shear is a sensible complement. Hydraulic power units provide the necessary pressure and flow rate; their sizing depends on the number of rams operated in parallel and the desired work progress.
Typical error sources and practical tips
- Insufficient drill pattern: uniform axis spacing and appropriate depth are crucial.
- Pressure increase too fast: better to work in stages and observe crack formation.
- Missing relief cuts: pre-separations improve edge quality and reduce spalling.
- Reinforcement neglected: plan prior locating (e.g., via scanning) and a shearing/cutting sequence.
- Insufficient support of the remaining structure: plan temporary shoring, especially for partial deconstruction.
Sustainability and emission aspects
The hydraulic splitter method operates with low emissions in terms of noise and vibration. Combined with targeted reduction and sorting, it supports the reuse of mineral construction materials. The controlled crack path reduces overbreak and material losses, conserving resources in both concrete demolition and natural stone extraction.
Documentation and quality assurance
Robust documentation includes drilling plans, pressure and force logs, photo standpoints, and information on sequence and cycle. For recurring work, analyzing crack formation, edge quality, and tool wear is recommended to continuously optimize parameters.
Distinction from punching and embossing processes
In metalworking, stamping refers to forming or separating sheet metal using presses. This understanding differs fundamentally from the hydraulic splitter method in construction and rock, which aims at splitting and crack formation in brittle materials. Avoiding confusion is important in order to select appropriate tools and safety measures.