Corrosion accompanies almost all work in construction, deconstruction, and the extraction of natural stone. It affects both structures—for example through reinforcement corrosion in concrete—as well as tools and steel attachments used in harsh environments. For Darda GmbH products such as concrete demolition shears, rock and concrete splitters, hydraulic power packs, combination shears, Multi Cutters, steel shears, tank cutters, and rock wedge splitters, a systematic corrosion protection is an essential basis for safety, availability, and service life. In concrete demolition and special deconstruction, during strip-out and cutting, in rock excavation and tunnel construction, in natural stone extraction, and in special operations, moisture, chlorides, CO2, abrasion, and temperature fluctuations act as drivers of corrosion processes. A practical approach to corrosion protection combines knowledge of the mechanisms, suitable protection systems, and consistent maintenance—always tailored to the application profile and environmental conditions.
Definition: What is meant by corrosion protection
Corrosion protection encompasses all measures that prevent or slow the material change and degradation of metallic materials through chemical or electrochemical reactions with the environment. Typical goals include preventing rust on steel surfaces, preserving the passive film on reinforcing steel in concrete, and ensuring the leak-tightness of hydraulic systems. Protection can be achieved through material selection, design detailing, coatings, inhibitory media, cathodic methods, controlled operating conditions, and appropriate storage. In the context of concrete demolition shears, rock and concrete splitters, and other attachments from Darda GmbH, this means protecting surfaces so that they remain functional over the long term despite mechanical loading, moisture, salt, and dust, while also properly accounting for corrosion on load-bearing components of structures when making deconstruction decisions.
Corrosion mechanisms and protection principles
In practice, corrosion usually arises from the interaction of an electrolyte (e.g., water with dissolved salts), oxygen, and a metallic material. Common forms include uniform corrosion, pitting, crevice corrosion, galvanic corrosion (dissimilar metal couples), and stress corrosion cracking. In concrete, reinforcement corrosion results from carbonation (pH reduction due to CO2) or chloride ingress; in plant and deconstruction environments, condensation, salt-laden spray, cavities, damaged coatings, and conductive deposits promote undercutting of protection systems. Protection principles therefore aim to eliminate at least one reaction partner: keep water out, limit oxygen ingress, passivate the material, equalize electrical potentials, or use sacrificial materials. In application, these principles are implemented through proper materials, surface systems, sealing concepts, fluid care, and scheduled maintenance.
Corrosion protection for concrete demolition shears and rock and concrete splitters
Concrete demolition shears and rock and concrete splitters operate in contact with moisture, stone dust, aggregates, and—in winter service or coastal climates—with chlorides. At the same time, high point loads and abrasion act on them. This results in a requirement profile: robust base materials, wear-resistant functional edges, well-adhering coatings in less stressed zones, and a design that minimizes water accumulation and dirt traps.
Material selection and surface systems
High-strength quenched and tempered steels at cutting edges or splitting wedges provide the necessary strength, while load-bearing structures can be combined with tough fine-grain steels. For corrosion protection, a layered concept has proven effective: areas subject to heavy mechanical loads often remain uncoated and are protected through regular care (cleaning, targeted oiling); adjacent zones receive robust primers and topcoats. Duplex systems consisting of zinc plus an organic topcoat can increase service life in exposed environments. Critical factors include careful edge rounding, suitable surface preparation, and sufficient film thicknesses at geometrically challenging locations.
Hydraulic systems and fluids
Hydraulic power packs, lines, and cylinders are sensitive to moisture, condensate, and fluid aging. Water content in the oil promotes internal corrosion and reduces lubrication performance. Leak-tightness, filtration, regular oil maintenance, corrosion-resistant couplings, and condensate management are therefore key elements. External steel components on cylinders benefit from smooth, well-cleaned surfaces and spot preservation after use.
Rebar corrosion in concrete and implications for deconstruction
In concrete demolition and special deconstruction, the condition of the reinforcement governs the approach. Carbonation lowers the pH, the passive film collapses, and rusting begins; chlorides from de-icing salts or marine climates can cause pitting. Rust expansion leads to spalling, cracking, and cross-section loss. This affects both structural stability and the choice of demolition method—for example, whether concrete demolition shears should cut the section in a controlled manner or whether rock wedge splitters should expand the concrete without explosives.
Carbonation and chlorides
Carbonation progresses depending on concrete quality, moisture, and CO2 content. Chlorides act locally, often in splash zones. Both mechanisms reduce reserve capacity. In practice, this means identifying corroded zones, taking restraint effects and voids into account, and planning the intervention to keep load redistribution under control. Tools such as concrete demolition shears enable cold, low-spark separations in reinforced concrete and support controlled deconstruction when structural stability is limited.
Deconstruction planning and occupational safety
Corrosion can expose hidden conditions or keep defects concealed. Before starting work, material condition, loss of cross-section, and anchorage locations must be assessed. Corroded reinforcement exhibits sharp fracture surfaces; edge loads and drop edges must be secured. When cutting exposed steels, steel shears and Multi Cutters are options; sparking should be minimized depending on the environment. In general: always plan measures specific to the asset and apply proven methods.
Corrosion in rock excavation, tunnel construction and natural stone extraction
Underground and in quarries, fluctuating humidity, abrasive dusts, and often saline waters prevail. Attachments such as combination shears, rock wedge splitters, and steel shears benefit from protective detailing: protected bearing points, sealed cavities, and drain holes to prevent water pooling. After use, cleaning, drying, and light preservation accelerate dry-back and reduce undercutting. In tunnel atmospheres with elevated chloride or sulfate content, maintenance intervals should be shortened and visual inspections for underfilm corrosion intensified.
Surface preparation and coating systems
The durability of coatings is determined during preparation. The goal is a clean, sound, and sufficiently rough surface. Mechanical loading in service also demands tough, repair-friendly systems. On Darda GmbH attachments, mixed constructions of uncoated functional edges and coated surfaces are common; touch-up coatings should fit the overall system.
Preparation steps
- Degreasing: Thoroughly remove oils, greases, and hydraulic fluids to ensure wettability.
- Derusting/roughening: Mechanically clean or blast as required; remove all loose layers completely.
- Edge rounding: Break sharp edges to achieve adequate film thickness at edges.
- Drying: Avoid residual moisture; consider temperature and dew point to prevent condensation.
Coating selection
- Primer with active anti-corrosion pigment or zinc-bearing: improves barrier and cathodic action.
- Intermediate and topcoat with high abrasion resistance: protects in dusty, mechanically stressed environments.
- Repair systems: easy to apply for partial areas after use; compatible with the existing coating.
- Duplex approach: combine metallic and organic protection mechanisms where possible.
Compliance with specified dry film thicknesses, recoat intervals, and curing conditions is crucial to avoid undercutting and edge rust. Requirements for surface preparation and coating systems should follow recognized state-of-the-art practice.
Corrosion protection during cutting operations on steel and tanks
During strip-out and cutting of steel sections or vessels, wall-thickness reductions caused by corrosion are safety-relevant. Tank cutters and steel shears are selected so that cutting forces and possible residual stresses remain manageable. In preparation, check material condition, connection points, and any residual contents in the vessel. Corroded areas tend to develop unpredictable cracks; therefore, a controlled cutting path and secure support are advisable. Low-spark methods can be advantageous in sensitive environments; suitability must be assessed for the specific asset.
Material combinations and galvanic corrosion on attachments
When different metals meet in a conductive environment, galvanic corrosion can occur. Typical examples include bolted joints, bearing housings, or repair zones. Protection is achieved through targeted material pairing, electrical isolation (e.g., seals and washers), tightly sealing coatings, and avoiding crevices where electrolytes can stagnate. For hydraulic connectors and couplings, regular inspection of contact surfaces and coating integrity helps.
Maintenance, inspection intervals and storage
Effective corrosion protection relies on routines. Post-use checks, periodic maintenance, and a suitable storage environment prevent consequential damage and ensure the readiness of concrete demolition shears, rock and concrete splitters, and other Darda GmbH tools.
Practical measures
- After use: Remove coarse dirt, rinse with clean water, dry; lightly preserve functional surfaces.
- Visual inspection: Identify damaged coatings, rust onset, and undercutting and repair promptly.
- Hydraulic care: Check for leaks, replace filters and oil as specified; monitor water content and particles.
- Screw and bolt connections: Check for corrosion in clamping areas and contact surfaces; apply torques per specification.
- Storage: Dry, ventilated, low-condensation; avoid direct floor contact and water ponding.
- Documentation: Record maintenance, coating repairs, and inspections in a traceable manner.
Environmental and sustainability aspects
Corrosion protection and environmental protection can be aligned: durable systems reduce maintenance, and proper cleaning minimizes the introduction of dusts and old coatings into the environment. When selecting cleaning and coating materials, ensure proper application and compliance with applicable environmental and occupational safety requirements. Seals and containment during cleaning and coating prevent particles and fluids from entering soil or water bodies.
Documentation and condition assessment
A structured condition assessment helps identify corrosion risks early: condition classes for surfaces, defined inspection points at exposed locations, photo documentation, and clear criteria for repairs create transparency. For structures, non-destructive testing methods and indicative measurements (e.g., carbonation depth or chloride content) support deconstruction planning. For attachments, recurring inspections provide reliable data to proactively plan maintenance windows, spare parts needs, and protection measures.