Steel construction denotes the planning, fabrication, assembly, adaptation, and the deconstruction of load-bearing structures made of steel. It includes halls, bridges, plant and industrial buildings, as well as composite constructions of steel and concrete. Over the life cycle of a steel structure, in addition to structural analysis, fabrication tolerances, and the corrosion protection system, separating and forming methods play a key role. During retrofit, building gutting, concrete demolition, and special demolition or during works in tunnel construction, concrete demolition shear, hydraulic wedge splitter, steel shear, cutting tool, combination shears, and Multi Cutters are established cold-working hydraulic systems, frequently powered by mobile hydraulic power units.
Definition: What is meant by steel construction
Steel construction refers to the erection and upkeep of load-bearing structures made of steel, including their nodes, connections, and joints to other construction materials. The range extends from simple post-and-beam system through trusses and frames to hollow sections and box girders. Hallmarks are high strength at low self-weight, precise prefabrication, rapid assembly, good dismantlability, and a pronounced suitability for circular use through single-grade separation. In practice, pure steel structures are just as common as composite system (composite beam, steel-composite slabs), which require special separation techniques during deconstruction.
Design fundamentals, connections, and fabrication
The load-bearing behavior in steel construction is based on harmonized cross-section, material strength parameters (strength, stiffness, notch toughness), and detail-appropriate nodes. Common connections are bolted, riveted (in existing structures), or welded; their selection influences the assembly sequence, fatigue resistance, and later dismantling. Hollow sections, rolled sections, and plate sheets are cut and drilled to precise dimensions in the workshop. Tolerances, edge quality, and surface preparation determine the quality of the weld seam and bolt pretension—as well as later separability. Already during planning it is worthwhile to consider access for tools such as steel shear and cutting tool, so that during retrofit or special demolition it is possible to cut cold, with few sparks, and in a controlled way.
Material properties and corrosion protection
Structural steels combine high load-bearing capacity with ductility, which makes the deformation behavior before fracture predictable. For durable use, corrosion protection system and constructive details that avoid water accumulation are decisive. Under elevated temperature exposure, fire protection measures are added that extend load-bearing safety in the event of fire. These layers and coatings influence later cutting and separating processes, because they shape edge formation, the release of composite partners, and waste separation.
Structural steels and profiled semi-finished products
Typical semi-finished products are I-, H-, and U-sections, angles, T-sections, hollow sections, and plates. Their selection follows load transfer (bending, compression, shear, torsion) and the node solution. For connections to concrete, stud bolt, base plate, and anchors are used. In existing structures, riveted connections are also found, which require special dismantling and cutting strategies.
Corrosion protection and fire protection
Coating systems, metallic coatings, and constructive corrosion protection extend service life. Fire protection layers (e.g., intumescent) influence surface treatment: during deconstruction they should be recorded separately by material. Cold-working separating techniques facilitate the clean delimitation of steel, concrete, and coatings.
Assembly sequence and construction site logistics
Steel structures are often delivered prefabricated and assembled on the construction site with cranes. Temporary bracing secures intermediate states. Surveying and adjustment work ensure the geometry before final connections are made or prestressed. Adaptation cuts on site are ideally performed with few sparks and minimized heat input to protect adjacent components, coatings, and installations. A hydraulic power pack supplies mobile cutting and pressing tools that remain accessible even in confined situations.
Deconstruction, building gutting, and separating methods
The orderly deconstruction of steel and composite structures requires selective separation, low vibration levels, and high control over cut edges. concrete demolition shear open concrete cross-sections in a targeted manner, expose reinforcement and steel components, and reduce load segments for subsequent cold cutting with steel shear, combination shears, or Multi Cutters. hydraulic wedge splitter create controlled split joints without impact and with limited crack propagation in adjacent components—a benefit for sensitive existing structures, in building gutting and in special demolition. Cutting tool separate tank shells, silos, or pipelines with few sparks, which can be relevant in areas with fire and explosion hazards. Such methods fit into the application areas of concrete demolition and special deconstruction, building gutting and cutting, as well as special operations, and support clean construction waste separation of building materials.
Selective dismantling for composite and reinforced concrete
For composite beams and decks the sequence is decisive: first, concrete and shear connectors are locally released, for example by targeted biting with shears. This is followed by cutting the exposed reinforcement and finally the steel components. This sequence reduces restraint stresses and uncontrolled fractures and improves the recycling quality of steel and concrete.
Cold cutting of steel structures
Steel shear, combination shears, Multi Cutters, and cutting tool rely on high cutting forces with minimal heat input. Advantages are clean edges, reduced sparking, and diminished influence on coatings and neighboring components. In enclosed spaces and sensitive environments such methods can lower noise emission, dust, and fire loads. Execution should always be in compliance with applicable occupational safety regulations and project-specific approvals.
Applications in rock excavation, tunnel construction, and foundations
In tunnel construction and special foundation engineering, steel arches, lattice girder beam, anchors, and reinforcement are interlocked with the rock and concrete composite. During retrofit or cross-section enlargements these materials must be separated by type. concrete demolition shear and Multi Cutters remove shotcrete and steel mesh, steel shear cut profiles and arch segments. For foundations, abutment, or rock cuttings, hydraulic wedge splitter as well as stone splitting cylinders help to open the massif with low vibration levels—a prerequisite for replacing steel column bases or anchor plate without endangering the surrounding structure.
Planning, structural analysis, and quality assurance
Robust planning considers load assumptions, assembly states, fatigue, tolerances, corrosion protection, and later accessibility for inspection, repair, and deconstruction. Model-based workflows support clash detection, assembly sequences, and the separation and deconstruction strategy. Quality assurance includes material certificates, dimensional checks, documentation of connections, and the evaluation of cut edges for adaptations and deconstruction cuts.
Typical sources of error and how to avoid them
- Insufficiently planned nodes: consider assembly and separation access early.
- Neglected intermediate states: calculate and document temporary bracing.
- Unsuitable separating methods: in sensitive areas, prefer cold-working hydraulic cutting.
- Missing material separation: choose the sequence so that steel, concrete, and coatings are recorded separately and cleanly.
- Underestimated fatigue: ensure detail sharpness at drillings and cut edges, minimize notch effects.
Occupational safety, environmental, and resource topics
Steel is highly recyclable. Selective deconstruction and clean cut edges improve recycling and reduce disposal costs. Cold-working methods reduce sparking, smoke, and thermal effects. In enclosed spaces they lower emissions and facilitate compliance with organizational and technical protective measures. Legal requirements vary by project and region; implementation should in principle be aligned with the recognized rules of technology and the respective applicable provisions.
Reference to products and application areas of Darda GmbH in the steel construction context
Across the life cycle of steel structures, the disciplines of steel construction, concrete construction, and separation technology converge. In building gutting and cutting, concrete demolition shear and hydraulic wedge splitter act to open and release mineral components in order to expose steel sections and reinforcement. Steel shear, Multi Cutters, combination shears, and cutting tool take over the controlled cutting of structural steel, plates, and composite joints. A hydraulic power pack provides the energy supply in mobile and stationary setups. These tools and methods are anchored in 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 operations, and support a safe, precise, and clean, single-grade working approach in steel construction.