Steel grids are ubiquitous in construction, industrial plants, and infrastructure: as load-bearing gratings on walkways, as protective guards on machines, as mesh reinforcement in reinforced concrete, or as lattice girder beam elements in slabs and walls. In deconstruction, building gutting, and concrete demolition, you encounter them in very different forms. For an efficient, controlled, and safe approach, it is crucial to understand how steel grids are built, how they behave under load, and how to process them with suitable hydraulic tools — such as concrete pulverizer units, steel shear tools, Multi Cutters, or stone and concrete hydraulic splitter systems from Darda GmbH.
Definition: What is meant by steel grids
Steel grids are planar or spatial structures made of steel bars, strips, or sections forming regular, usually rectangular meshes. Typical expressions are gratings (for pedestrian and vehicle traffic), protective and barrier grids, as well as mesh reinforcement in reinforced concrete. Steel grids are created by welding, pressure welding, or bolting of bearing and filler bars; in concrete construction, welded mesh reinforcement and lattice girder beam elements are also included. Materials range from unalloyed structural steel to stainless steel; corrosion protection is often provided by hot-dip galvanizing or coating.
Types and composition of steel grids
Steel grids differ by function, manufacturing method, and mesh geometry. These differences determine load-bearing capacity, cutting behavior, and the appropriate approach in deconstruction.
Gratings and protective grids
- Pressure-welded gratings with bearing and filler bars for walkways, platforms, stairs, and stages
- Safety and protective grids on machines, façades, and shaft covers
- Grids with slip-resistant profiles for industrial environments
Mesh reinforcement and lattice girder beam elements in concrete
- Welded mesh reinforcement as planar reinforcement in slabs, walls, and floor slabs
- Lattice girder beam elements (longitudinally connected bars with diagonal bars) for bracing, often in precast elements
- Local inserts around openings, columns, and anchorage points with increased bar density
Materials and surfaces
- Structural steels with balanced strength and toughness
- Stainless steel in corrosive environments, for example in wastewater treatment or chemical facilities
- Corrosion protection via hot-dip galvanizing, duplex systems, or coatings
Important for deconstruction: Material, bar diameter, and connection technique (welded, plugged, bolted) influence whether separation, splitting, or crushing takes priority.
Steel grids in concrete demolition and special demolition
In reinforced concrete, the reinforcement forms a steel grid that absorbs tensile forces. During demolition, the team therefore always encounters two material worlds: brittle concrete and ductile steel.
Sequence: Release concrete, cut steel
- Expose: With concrete pulverizer tools from Darda GmbH, the concrete is crushed in a controlled manner until the reinforcement is exposed.
- Cut: Protruding steel grids, mats, and bars are cut to length with steel shear tools or Multi Cutters.
- Rework: Edges are trimmed, sections bundled, disposal prepared.
Where vibrations must be minimized (for example in special demolition near sensitive infrastructure), stone and concrete hydraulic splitter systems as well as rock wedge splitter units from Darda GmbH enable low vibration levels widening of existing cracks. This reduces stresses in the surrounding matrix and facilitates subsequent cutting of the steel grids.
Steel grids in building gutting and cutting
Outside reinforced concrete, steel grids are commonly encountered as gratings, stair treads, railings, and protective guards. In deconstruction of existing buildings and plants, compact, precise cutting tools are used to detach sections cleanly and recover them in a controlled manner.
Tool selection by component
- Steel shear: For massive bars, nodes, and frame elements of grid constructions
- Multi Cutters: For mixed materials (steel sections, sheet metal, reinforcement) in rapid succession
- Combination shears: When gripping, pressing, and cutting are required in a single operation
- Tank cutters: For cut-intensive, thin-walled steel components in plants and vessels
In confined situations (special operations, building gutting), compact shear attachments powered by hydraulic power pack units from Darda GmbH prove their worth, delivering high performance at low weight.
Rock excavation, tunnel construction, and natural stone extraction: touchpoints with steel grids
In geotechnical contexts, steel grids typically appear as protection elements: nets, anchor plates, temporary gratings, or provisional walkways. When adjustments or deconstruction sections are required, cutting such grids is unavoidable.
Controlled approach
- Open rock and concrete with stone and concrete hydraulic splitter tools to establish access
- Cut and dismantle protective grids in sections so as not to impair the stability of temporary construction states
- Machine-proximate work with precise shears to minimize sparking and material distortion
In tunnel construction, special attention is paid to the sequence: first the load paths must be identified, then grid components are released in segments that are neutral to the load-bearing structure. Hydraulic tools enable a procedure with low vibration levels.
Material behavior and cutting strategies
Steel grids behave elastically-plastically under cutting loads; spring-back, jamming in the cutting gap, and stresses at node areas are typical. A suitable strategy reduces tool load and increases process safety.
Practice-oriented notes
- For mesh reinforcement, first relieve the edges, then cut the area into strips
- Cut gratings preferably at nodes near bearing bars to limit distortion
- Process coated or galvanized grids with suitable cutting jaws; avoid damage to functional surfaces
- For thicker bar diameters, combine pre-cutting and counter-support to minimize crushing
Concrete pulverizer tools create the prerequisite for clean cuts: the better the concrete is trimmed back, the lower the lever forces on the steel grid and the more efficiently steel shear tools and Multi Cutters operate.
Hydraulic power packs, performance, and ergonomics
Cutting and splitting performance is determined by the hydraulic flow. Hydraulic power pack units from Darda GmbH supply concrete pulverizer tools, steel shear tools, combination shears, and tank cutters with the necessary pressure and flow rate, ensuring that even tough grid steels are cut reproducibly. Short hose runs and a well-tuned pressure build-up improve response time, operator comfort, and cut quality.
Safety and environmental protection aspects
Work on steel grids involves risks from spring-back, pinching strips, falling parts, and sharp cut edges. In addition, noise emission and fine dust can arise, for example during upstream concrete breaking.
Protective measures at a glance
- Plan a cut path free of jamming, secure components, and fix sections to prevent uncontrolled dropping
- Anticipate spring-back: grip material centrally, define the cutting sequence, consider tension and compression zones
- Adapt personal protective equipment to the task and secure the work environment
- In sensitive areas, prefer low vibration levels methods (splitting, shear work) to reduce emissions
Legal and occupational safety requirements are context-dependent and should be coordinated on a project basis with the responsible authorities.
Planning, documentation, and quality
A robust separation concept begins with an as-built survey: Which grid types are installed, how are they anchored, what material thicknesses are present, are there coatings or corrosion damage?
Checkpoints for project start
- Record mesh size, bar diameter, and node points
- Identify anchors (welded, bolted, dowelled)
- Consider environmental influences (corrosion, contamination, media)
- Assess spatial constraints and the load effects of temporary states
Documentation supports traceability: cut locations, sequence, tool selection, and disposal routes are recorded to optimize processes and increase safety.
Challenges and solution approaches when dealing with steel grids
Depending on the application area, typical issues arise that can be mitigated with suitable tools and methods.
Tough material, limited access
- Pre-cut with Multi Cutters, finish with steel shear tools as the workspace opens up
- Trim concrete laterally with concrete pulverizer tools to shorten lever arms
- For thick nodes, provide intermediate support in cut areas to limit deformation
Mixed assemblies
- Use combination shears when gripping and cutting are required without tool change
- Use tank cutters to make dimensionally accurate cuts on thin-walled steel components before releasing grid inserts
- Size hydraulic power pack capacity for peak loads to avoid cycle congestion
Material protection and corrosion
In deconstruction, functional material is often to be reused, for example gratings made of stainless steel or galvanized protective grids. Cut edges are prone to corrosion and should be produced gently. Mechanical cutting with hydraulic shear tools generally creates less thermal influence than thermal cutting; this protects edge zones and reduces rework. If required, cut surfaces can subsequently be cleaned and preserved to maintain corrosion protection.
Role of stone and concrete hydraulic splitter systems in the overall workflow
Splitting methods complement the cutting of steel grids where the concrete matrix must first be opened or where cracks are to propagate in a defined manner. Stone and concrete hydraulic splitter systems from Darda GmbH generate high splitting forces with low emissions and are therefore suitable for concrete demolition and special demolition, but also in rock excavation and tunnel construction as well as in natural stone extraction. This creates access, reduces reinforcement restraint, and facilitates the subsequent cutting of exposed steel grids.
Disposal and recycling
Steel grids are valuable secondary raw materials. Clean separation by type, dimensionally accurate cutting, and clean bundling facilitate transport and recycling. In concrete demolition, the sequence of crushing (concrete pulverizer), cutting (steel shear/Multi Cutters), and demolition sorting separates material flows efficiently. This conserves resources and reduces disposal effort.