Remaining strip-out is the precise final stage of selective deconstruction. After finishes, light partition walls, and building services have been removed, the focus shifts to the last fixtures, residual components, and hard-to-reach areas. The aim is to cleanly expose the load-bearing system, sort the material flow, and prepare structures for subsequent concrete demolition or refurbishment works—with low vibration levels, low dust, and in a controlled manner. In this context, solutions developed at Darda GmbH such as concrete demolition shears as well as rock and concrete splitters are frequently used, as are hydraulic power units, combination shears, Multi Cutters, steel shears, cutting torches, and rock wedge splitters—depending on the task and application area.
Definition: What is meant by remaining strip-out
Remaining strip-out refers to the targeted removal of the components and fixtures left after the coarse strip-out. These include, among others, remaining sections of concrete elements (e.g., parapets, upstands, ring beams, beams, landings), localized backfilling, load reserves at slab edges, foundation heads, embedded steel sections, anchors, heavy-duty anchors, and pipes embedded in concrete. Remaining strip-out bridges the gap between dismantling and structural removal, ensures material separation, and creates defined interfaces for the subsequent steps such as cutting, core drilling, or controlled demolition. It is preferably carried out using hydraulic, mechanical, and thermo-mechanical methods to keep impacts on structural stability low and to increase recycling potential.
Process and work steps in remaining strip-out
The process follows a clearly structured sequence: existing-conditions analysis and clearance/line tests, protective and safety measures, selective dismantling of the remaining fixtures, controlled separation of residual components, material separation and removal/disposal, final cleaning, and documentation. Depending on component geometry and boundary conditions, concrete demolition shears are used for breaking and biting off concrete, while rock and concrete splitters handle non-explosive opening and splitting of massive sections. In addition, steel shears and Multi Cutters are used for reinforcement and profiles, with hydraulic power packs serving as the energy source.
Equipment selection and process engineering
The choice of method depends on geometry, strength, reinforcement content, accessibility, emission limits, and schedule. Priority is given to methods that enable controlled, repeatable separation and protect the surroundings. A combination of concrete demolition shears, rock and concrete splitters, and cutting methods, supported by Darda GmbH hydraulic power packs, often proves effective.
Concrete demolition shears in detail
- Suitability: residual edges, cantilevers, beams, upstands, stair landings, balcony elements.
- Advantages: controlled biting with good visibility of the separation zone, low vibration levels, material-separated placement of concrete and reinforcement possible.
- Practice: Work in sections to avoid load redistributions; reinforcement is exposed and cut with steel shears.
Rock and concrete splitters in detail
- Suitability: massive components, foundation heads, walls with high compressive strength, components in sensitive environments.
- Advantages: Non-explosive, low vibration levels splitting; defined crack propagation; reduced dust compared with dry separation cuts.
- Practice: Design the drill-hole pattern according to structural requirements and component thickness; set splitting cylinders, monitor load transfer, and size pieces for haulage logistics.
Hydraulic power packs as the power source
- Function: Supply concrete demolition shears, combination shears, Multi Cutters, steel shears, and splitting cylinders with constant hydraulic pressure.
- Aspects: Power reserve for tough materials; protect hoses and minimize trip hazards; ensure proper leak-oil handling.
Application areas and typical use cases
Remaining strip-out is closely connected with the application areas of concrete demolition and special demolition, building gutting and cutting, rock excavation and tunnel construction, natural stone extraction, as well as special deployments. Its precision makes it the interface between dismantling and structural removal.
Concrete demolition and special demolition
- Expose separation joints, remove residual bearings, and separate corbels and beams with concrete demolition shears.
- Split foundations and wall bases using rock and concrete splitters to produce transport-ready sizes.
Strip-out and cutting
- Preparation for saw cutting and core drilling by creating plannable edges and voids.
- Biting off concrete residues along slab perimeters, then trimming the reinforcement with steel shears or Multi Cutters.
Rock excavation and tunnel construction
- Transferred principles: splitting technique for edge zones of shotcrete and excavation remnants when vibrations must be avoided.
- Controlled release of wedged areas without explosives, e.g., with rock wedge splitters.
Natural stone extraction
- Selective release of remaining webs and anchors; splitters enable material-friendly separations in rock.
Special deployment
- Tank dismantling with cutting torches in combination with deconstruction steps on the concrete foundation.
Planning, structural analysis, and interface management
Remaining strip-out intervenes in existing load paths. A coordinated approach with structural engineering is essential to safely manage intermediate states and define the sequence of separations. Interfaces to building services, fire protection, and disposal are clarified at an early stage to avoid downtime.
Survey of existing conditions
- Determine material strengths, reinforcement routing, layer build-up, and anchorage.
- Identify relevant connections to adjacent structural elements and temporary load redistributions.
Work sequence and intermediate states
- Proceed from less loaded to more heavily loaded sections.
- Provide temporary shoring where load redistributions are possible.
Safety and environmental protection aspects
Occupational safety, health, and environmental protection have priority. Requirements vary by region and must always be observed. Low-emission methods are often preferable in sensitive environments.
- Noise and vibrations: low vibration levels splitting technique and metered use of shears.
- Dust: wet operation, dust extraction plant, and protective enclosure.
- Hazardous substances: check potential contamination in advance; handle appropriately in accordance with applicable regulations.
- Securing loads: secure components against uncontrolled tipping or falling; cordon off work areas.
- Hydraulic safety: regularly check operating pressure, hydraulic hose line routing, and couplings.
Material separation and recycling
The quality of remaining strip-out is reflected in the purity of the recovered materials. Clean separation facilitates the reuse of aggregates and metals and reduces disposal costs.
- Mineral fractions: keep concrete debris as free of foreign materials as possible.
- Metals: separate reinforcement with steel shears or Multi Cutters; store sorted by type.
- Composite materials: organize separate collection and proper treatment.
Methodical execution details
The following principles support controlled, efficient remaining strip-out under varying boundary conditions.
Sequencing and takt
- Small, manageable steps; continuous monitoring of component responses.
- Parallel material logistics to keep routes clear and avoid double handling.
Quality control
- Visual inspection for hidden inserts and embedded parts; check final dimensions against reference points.
- Photo documentation of separation points and storage.
Performance and quality indicators
Measurable indicators support project control and documentation.
- Area or mass output per shift under defined boundary conditions.
- Emission values (noise, dust, vibration) within the target corridor.
- Material purity and recycling rate of material flows.
- Schedule adherence per construction phase and downtime.
Typical sources of error and how to avoid them
Common risks can be minimized through careful planning and methodical execution.
- Insufficient knowledge of the existing structure: clarify component build-ups and anchorages before starting.
- Oversized interventions: choose fine shear or splitting sequences instead of coarse removals.
- Missing shoring: structurally secure intermediate states.
- Mixed material streams: consistent material separation directly at the source.
Practical tool examples in remaining strip-out
Depending on the component and boundary conditions, different tool combinations have proven themselves in day-to-day deconstruction.
- Concrete edge along slab perimeter: bite with concrete demolition shears, trace and cut the reinforcement, produce a flush edge.
- Foundation head in a sensitive environment: drill-hole row, splitting with rock and concrete splitters, controlled segmentation.
- Remaining profile in a shaft: shorten with Multi Cutters, rework with hydraulic demolition shear, protect the shaft walls.
Project documentation and verification
Transparent documentation creates traceability and facilitates subsequent steps in concrete demolition or refurbishment. This includes work logs, photo documentation, disposal and recycling certificates, and measurement reports on emissions where specified. Structured filing makes it possible to answer queries quickly and to verifiably demonstrate the quality of the remaining strip-out.