Removal in Concrete Demolition & Rock Excavation

Removal denotes the targeted elimination of material from structures or natural rock bodies. In practice, the spectrum ranges from the controlled concrete deconstruction of elements to steel cutting and the splitting of rock. Decisive factors are precise force application, the desired crack propagation, and a predictable outcome with respect to piece sizes, emissions, and schedule. Tools such as concrete pulverizers and hydraulic wedge splitters from Darda GmbH form core methods for this, especially when low vibration levels, reduced emissions, and selectivity are required.

Definition: What is meant by Removal

Removal is the controlled elimination of material using mechanical, hydraulic, or cutting methods. The goal is to reduce volume, separate components, or decouple load paths. In concrete demolition, removal includes fragmenting concrete, exposing and cutting reinforcing steel, and producing defined fracture faces. In rock mechanics, removal refers to dislodging blocks or slabs along natural or induced weakness planes. Key indicators include removal performance (e.g., mÂ³/h), removal rate, specific energy demand, piece-size distribution, and emissions (noise, dust, vibrations).

Overview of removal methods

The choice of removal method depends on the material, component geometry, reinforcement level, accessibility, environmental constraints, and the objective of deconstruction. Mechanical-hydraulic methods enable precise, selective, and often low-vibration interventions.

Splitting (hydraulic): hydraulic wedge splitters and rock splitting cylinders from Darda GmbH generate high, localized tensile stresses via wedge or cylinder systems. Typical for rock excavation and tunnel construction, but also for massive concrete foundation elements when a low-vibration solution is required.
Crushing/pressing: concrete pulverizers grip and break concrete through high closing forces. Ideal for selective deconstruction, building gutting, ceiling demolition and wall demolition, as well as exposing reinforcement.
Cutting/separating: steel shear, combination shears, and Multi Cutters separate sections, reinforcement, and mixed materials. cutting torch units are suitable for special tasks on tanks and plate material.
Combined methods: Splitting to initiate cracks and reduce volume, followed by pulverizer or shear work to optimize piece size and separate steel.

Removal in concrete demolition and special deconstruction

In the removal of concrete components today, selectivity is combined with safety and efficiency. Material removal is planned; components are fragmented to facilitate transport, recycling, and the separation of material streams.

Selective crushing with concrete pulverizers

concrete pulverizers act by peeling and pressing. They enable controlled fractures, minimize secondary damage, and expose reinforcement. This improves material separation and simplifies the disposal chain.

Low-vibration removal with rock and concrete splitters

With hydraulic wedge splitters, stresses are introduced in a targeted manner along borehole axes. This method is suitable for massive, thick-walled components, bridge foundations, machine foundation elements, or areas with sensitive surroundings where low vibration and noise levels are required. Purpose-designed rock and concrete splitters enable predictable crack propagation with minimal disturbance.

Hydraulic power packs as the energy source

Hydraulic power packs from Darda GmbH provide pressure and flow to match demand. A stable hydraulic supply directly influences removal speed, repeatability, and tool preservation. Selecting appropriate hydraulic power units supports consistent performance and longevity.

Rock excavation, tunnel construction and natural stone extraction

In rock removal, controlled crack guidance is key. Rock splitting cylinders and hydraulic wedge splitters use drilling patterns to define load paths and release blocks with targeted geometry. This minimizes vibrations, protects surrounding structures, and preserves the desired block size for transport.

Drilling pattern and crack control

Borehole diameter, spacing, edge distances, and sequencing determine crack initiation. In practice, work proceeds from the edge toward the center to avoid spalling and guide the fracture front.

Building gutting and cutting

In structural interiors, separation work is often performed under confined conditions. Compact tools are required that can grip precisely, cut, and keep piece weights manageable.

Shears and cutters in existing structures

combination shears and Multi Cutters cover variable material mixes, for example in installations, beams, or reinforcement bundles. steel shear units are deployed for removing steel sections, beams, and reinforcement bundles. Compact steel shears address confined spaces.

Performance indicators and influencing factors

Material properties: strength, density, grain structure, moisture, reinforcement ratio.
Geometry: component thickness, edge distances, embedment, support conditions.
Accessibility: working space, lifting gear availability, attachment points, visibility.
Hydraulic parameters: system pressure, flow rate, temperature stability of the hydraulic power packs.
Tool condition: wear, cutting-edge geometry, tightness, maintenance state.
Environment: vibration and noise limits, dust constraints, neighbor protection.
Process organization: takt planning, piece-size strategy, logistics and haulage logistics.

Planning, safety and emission control

Every removal process starts with investigation and planning: material analysis, utilities and embedded items, load-bearing behavior, load redistribution, and protection zones. Safety concepts account for fall hazards, crushing, cutting, hydraulic pressure, and the controlled removal of load paths. Emissions are reduced by water misting, extraction, enclosures, and low-vibration methods. Depending on the project, regulatory requirements, evidence, and monitoring measures may be necessary and should be integrated early.

Process chain: From positioning to haulage logistics

Survey and clearance measurement; define removal objectives and limits.
Select the method: splitting, pulverizer work, shears, or combined sequences.
Set-up: laydown areas, hydraulic power packs, hose routing, protection zones.
Preparation: drilling pattern for splitters or pilot cuts/setting points for pulverizers.
Primary removal: splitting cycles or pulverizer cycles for volume reduction.
Secondary removal: re-breaking, piece-size optimization, stripping steel from concrete.
Steel separation: steel shear, attachment shear or Multi Cutters.
Sorting and haulage logistics: separate material streams for recycling and disposal.
Inspection: visual checks, dimensional control, documentation of emissions.

Quality assurance and documentation

Quality in removal is reflected in reproducible fracture patterns, adherence to tolerances, limited emissions, and cleanly separated materials. Documentation includes target/actual comparisons, measurements from vibration or noise monitoring, photo records, material certificates, and maintenance status of the tools used.

Practice-oriented scenarios

Foundation removal in sensitive surroundings

Massive foundations are released into blocks with hydraulic wedge splitters and then downsized with concrete pulverizers. The low-emission sequence protects adjacent components.

Ceiling demolition in existing structures

Segmented crushing with concrete pulverizers, removal of edge strips, and controlled setting down of the segments. Reinforcement is cut with steel shear.

Rock breakout in tunnel heading

Set the drilling pattern, perform splitting cycles with rock splitting cylinders, release and load the blocks. Benefit: targeted crack control with low vibrations.

Tool selection by material and objective

concrete pulverizers: fragmenting concrete components, exposing reinforcement, selective deconstruction.
hydraulic wedge splitters incl. rock splitting cylinders: low-vibration release of massive concrete and rock bodies.
steel shear: cutting sections, reinforcement, and steel beams.
combination shears and Multi Cutters: flexible separation tasks with mixed materials.
cutting torch: special tasks on tanks, plates, and sheet metal.
hydraulic power packs: tool- and demand-appropriate supply of pressure and flow.

Tips for efficient, material-friendly removal

Define the removal target precisely: piece sizes, separation joints, residual load-bearing capacity.
Combine splitting and pulverizer work to minimize forces.
Adapt drilling patterns to component thickness, reinforcement, and edge distances.
Warm up the hydraulic system; match pressure/flow to tool demand.
Inspect tools regularly; address wear early.
Integrate dust and noise protection; isolate working areas.
Design lifting gear and logistics for planned piece weights.
Continuously check and document readings (vibration, noise).

Limits and alternatives in removal

With very high reinforcement ratios, prestressing elements, or highly heterogeneous composites, crack control can be challenging. In such cases, the process is often broken down into smaller steps: preparatory relief cuts, local splitting, then pulverizer or shear work. Where necessary, cutting methods are added to define edges or separate embedded items. The decisive factor is a combination of methods that equally considers structural analysis, safety, emissions, and scheduling.