Sealing is a central principle in demolition works, deconstruction and rock excavation: energy, pressure, or fracturing forces are directed so that components release in a controlled manner, cracks propagate along intended paths, and emissions such as dust, noise, and fragments remain limited. Whether in concrete demolition and special demolition, in rock excavation and tunnel construction, or during building gutting – sealing connects planning, material selection, and process engineering. It is closely related to work equipment such as hydraulic rock and concrete splitters, concrete demolition shear, stone splitting cylinders, or combination shears that support controlled separation at different phases of the intervention.
Definition: What is meant by sealing
Sealing refers to the targeted closing off, filling, or covering of openings, boreholes, joints, and edges to concentrate forces, pressure waves, or fracture processes and to prevent uncontrolled spread. Classically, the term comes from blasting technology (borehole seal for energy confinement), but it should be understood more broadly: even in mechanical methods – for example, in hydraulic splitting of concrete or rock – sealing performs a guiding and damping function. Objectives include:
- Targeted crack guidance, limiting breakout, and protecting adjacent components
- Reducing dust, noise, and particle ejection
- Ensuring stability during partial dismantling and special operations
- Improving process quality and repeatability
Fields of application and objectives of sealing
In practice, the spectrum ranges from borehole sealing in natural stone extraction to covering openings during building gutting and crack steering in concrete deconstruction. In combination with concrete demolition shear, sealing is often used to stabilize separation cuts, predetermined breaking points, and component edges so that concrete parts can be released in a controlled way. For stone and concrete splitters, a properly prepared borehole with sealing measures (e.g., stopping up open cavities, closing surface cracks) promotes the targeted force input of the splitting system.
Techniques and materials for sealing
The choice of sealing technique depends on material, geometry, environmental requirements, neighborhood protection, and workflow. Proven options include:
Granular sealing materials
Drilling fines, sand, or fine chippings are placed in layers and compacted. Particle size distribution influences the degree of damping: fine fractions seal better, coarse fractions increase friction. Granulates are universal, readily available, and suitable for concrete and natural stone.
Plastic and cohesive materials
Clayey materials, clay/bentonite, or pasty compounds close cavities very well and reduce leakage. They are advantageous in irregular borehole geometries and on moisture-sensitive substrates. Excessive moisture can, however, reduce set strength.
Mechanical stoppers and plugs
Sealing stoppers, rubber cones, or telescopic plugs create a positive-locking closure. They are reproducible, quickly installed, and well suited for recurring applications. Selection is based on borehole diameter and the required contact pressure.
Foam and hybrid sealing
Foam sealing (e.g., two-component systems) adapts to the substrate, seals porous zones, and reduces particle ejection. They are often combined with granular layers. They are useful in dust-critical environments such as hospitals or sensitive production areas.
Water sealing
Water bags or water-filled hoses act as both mass and damper. They are low-dust and reduce air blast and noise peaks. In frost-prone areas or with water-sensitive components, alternatives should be considered.
Coverings and surface sealing
Fabric tarps, rubber mats, timber layers, or composite panels are laid over separation cuts and work zones to limit fragment flight and sound. In conjunction with concrete demolition shear, this protects adjacent surfaces and supports a calm separation.
Borehole sealing in rock excavation and tunnel construction
In rock excavation and tunnel construction, sealing serves to keep energy in the borehole and to limit rock loosening to the target area. Decisive factors are borehole diameter, seated length of the sealing, material pairing, and proximity to free surfaces. In underground work and heading, strict control of sealing quality is essential to avoid breakouts along joints and to preserve rock faces.
Influencing factors
- Geology: layering, joint spacing, strength, groundwater flow
- Borehole geometry: diameter, depth, squareness, cleanliness
- Sealing material: grading band, moisture, compactability, temperature behavior
- Ambient conditions: proximity to structures, safety distances, emission limits
Sealing in non-explosive methods
Even without explosives, the principle remains the same: forces should act, but not run wild. With stone and concrete splitters and stone splitting cylinders, borehole quality, surface sealing, and the covering of edges steer crack propagation. A clean, coaxial borehole and the closing of open pores at the surface prevent cracks from running uncontrollably toward visible faces.
Crack guidance and pre-weakening
Predetermined breaking points created by core drilling or shallow saw cuts can be supplemented with coverings, damping mats, and localized sealing so that control cracks form between the weakened zones. This improves the interaction with concrete demolition shear, which then releases the component along these lines.
Building gutting and cutting
When removing installations and opening shafts, penetrations, channels, and joints are often temporarily sealed with mats, tarps, or stoppers. The goal is to keep dust and fine particles within the work area until cutting and shearing operations are completed.
Dust, noise, and vibration attenuation
Sealing is one element of emission protection. In sensitive environments – hospitals, schools, densely built neighborhoods – it is combined with water mist, localized extraction, and low-vibration methods. Concrete demolition shear and Multi Cutters operate with low vibration; sealing at edges and openings retains residual dust and fragments.
Practical measures
- Targeted covering of visible edges and window openings
- Localized foam sealing for dust-intensive separation cuts
- Water bags or mats for damping at bearings
- Cleaning and closing boreholes prior to splitting
Planning, design, and occupational safety
Sealing requires forward-looking planning. The basis includes building diagnostics, geology, the sequence of cuts and demolition, protected assets in the surroundings, and the selection of equipment. For blasting works, special qualification and permitting requirements apply; information here is always general and does not replace case-by-case assessment. For mechanical methods, load cases, intermediate states, and retention measures must be considered.
Procedure
- Survey: material, reinforcement, edge distances, crack patterns
- Method selection: splitting, shears, cutting, combinations
- Sealing concept: material, seated lengths, covered areas, transitions
- Protection measures: dust, noise, fragments, vibration, third-party protection
- Monitoring: visual inspections, measurements, documentation
Quality assurance and documentation
A reproducible sealing effect results from consistent execution. This includes cleaning the boreholes, placing granular media in layers, controlled tightening of mechanical stoppers, and complete covering of exposed edges. Records of material, quantity, and seated lengths support traceability.
Checkpoints
- Borehole homogeneity and surface condition
- Sealing material: origin, moisture, particle size
- Seated length and degree of compaction
- Visual inspection for leakage, dust escape, edge spalling
Typical errors and how to avoid them
- Seated length too short: leads to uncontrolled breakout – remedy by increasing the sealed section
- Incorrect particle grading: fines content too low – adjust the mix
- Insufficient borehole cleaning: residual fines reduce frictional lock – blow out/brush
- Missing surface covering: fragment flight possible – provide mats/panels
- Unconsidered cavities: seal hidden channels first – then proceed
Interfaces to equipment and power units
Sealing delivers its benefits in concert with the tools used. Stone and concrete splitters and stone splitting cylinders benefit from tight, coaxial boreholes and from closing open edge zones; this concentrates the spreading force. Concrete demolition shear releases components along prepared weakened lines – coverings and edge sealing reduce spalling. compact hydraulic power units supply energy for splitting and cutting tools; their smooth operation can be complemented with sealing and damping measures to further reduce emissions. Combination shears, Multi Cutters, steel shears, and tank cutters work more precisely when adjacent cavities are temporarily closed and cut edges are covered to prevent fragment flight.
Application-specific considerations
Concrete demolition and special demolition
In partial deconstruction and special operations, controlling crack paths and residual load-bearing capacity is paramount. Sealing at edges, closing service channels, and covering visible faces support work with concrete demolition shear and concrete cutting.
Rock excavation and tunnel construction
In natural stone extraction and tunnel heading, sealing protects adjacent layers and preserves planar fracture surfaces. Borehole sealing, geometry, and seated length are matched to jointing and bedding conditions.
Building gutting and cutting
When opening shafts, channels, and cavities, temporary sealing prevents the distribution of dust within building structures. Local coverings protect interior finishes and technology until cuts are made and components are removed with shears.
Sustainability and resource conservation
Properly planned sealing lowers emissions, minimizes rework, and reduces material losses due to uncontrolled breakout. Reusable stoppers, reusable coverings, and water-saving damping methods contribute to resource conservation. This protects components, reduces transport effort, and improves working conditions on the construction site.
Terminology and usage
In technical language, sealing is also described depending on context as borehole sealing, stemming, damping, or covering. The deciding factor is the function: enclose, guide, damp. In connection with Darda GmbH equipment, the range extends from preparing splitting boreholes to flanking coverings in shearing and cutting processes – always with the goal of working in a controlled and low-emission manner.