Explosives are among the most important tools of blasting technology in construction, mining and tunneling, as well as in natural stone extraction. They enable the targeted loosening, fragmentation, and removal of rock and concrete when mechanical methods alone are insufficient or economical. At the same time, numerous situations exist in which, for reasons of emissions control, safety, or tight boundary conditions, hydraulic and cutting methods are preferred. In these cases, for example at Darda GmbH, stone and concrete splitters, concrete demolition shears, combi shears, multi cutters, steel shears, tank cutters, hydraulic power packs, and rock wedge splitters are used, often in combination with or as an alternative to explosives.
Definition: What is meant by explosives
Explosives refers to explosive substances along with their initiation and auxiliary means, designed to release large amounts of energy in a very short time. This energy transfer breaks rock and concrete, separates components, and releases bonded materials. In practical usage, the term encompasses both the actual explosive (e.g., emulsion explosives, ANFO, cartridged explosives) and initiation devices (electric, non-electric, electronic), detonating cord, boosters, and additional accessories. Explosives are used exclusively by appropriately trained personnel and are subject to strict rules for storage, transport, work planning, and documentation.
Types, properties, and operating principle of explosives
Explosives act through a rapid chemical reaction that generates pressure and shock waves. These waves exceed the tensile and shear strength of concrete or rock and lead to fragmentation. Key distinctions concern energy content, brisance, water resistance, temperature behavior, handling, and compatibility with initiation systems. The right combination of explosive and initiation technology determines efficiency, fracture pattern, vibrations, and safety at the place of use.
High and low explosives
High explosives are brisant, produce high detonation velocities, and cause intensive fragmentation and sharp fracture surfaces. Low explosives release energy more slowly and are used primarily where heave is more important than strong fragmentation. In practice, especially in construction and rock applications, water-resistant emulsion explosives, ANFO mixtures (for dry boreholes), cartridged explosives for smaller borehole diameters, as well as detonating cord for transfer and synchronization of initiation impulses are used.
- Emulsion explosives: Robust, adaptable, frequently used in rock and in wet boreholes.
- ANFO: For dry use, economical for large-volume borehole charges.
- Cartridged explosives: Easy to dose, suitable for smaller boreholes in concrete and rock.
- Detonating cord: Transfers initiation energy, used for coupling charges.
Initiation systems and accessories
Initiation devices provide the starting impulse and structure the temporal sequence. Non-electric systems are insensitive to electromagnetic influences; electric systems allow clear signals; electronic detonators enable finely graduated delays for precise control of vibrations and fracture patterns. Boosters establish reliable coupling between the initiator and the main charge. For reasons of stability and safety, initiation devices and explosives are stored strictly separately and only combined at the jobsite.
Effects in construction and rock
The effect of an explosive manifests as fragmentation, heave, vibrations, and airborne sound. In concrete demolition, controlled fracture patterns are crucial to avoid damaging remaining structures. In rock excavation, the rock mass is deliberately loosened; in tunneling, the tunnel face must remain stable and the excavation contour clean. Delayed initiation sequences reduce vibration peaks and improve break quality, but require careful planning and documentation.
Application contexts and selection criteria
Whether explosives are used depends on geology or component build-up, boundary conditions (distances, neighboring buildings, protected assets), time and cost frameworks, and legal requirements. Blasting measures are often combined with hydraulic methods to perform fine demolition, selective deconstruction, or secondary fragmentation efficiently and with low emissions.
Concrete demolition and special deconstruction
In the controlled deconstruction of bridges, foundations, shafts, or massive concrete blocks, clean separation joints and limited vibrations are important. Explosives enable the release of large cross-sections. For subsequent sorting and the controlled removal of remaining zones, concrete demolition shears are used, reinforcement is cut with steel shears, and component edges are reworked with combi shears or multi cutters. Where blasting is ruled out for reasons of emissions or heritage protection, stone and concrete splitters and rock wedge splitters are deployed, supported by powerful hydraulic power units.
Rock excavation and tunneling
In rock, explosives have traditionally been used for extraction and advance. The excavation contour must be stable and reproducible. In sensitive sections, near structures, or in geological fault zones, low-vibration methods are required—especially in rock demolition and tunnel construction. Stone and concrete splitters and rock wedge splitters allow controlled separation without detonation pressure and are therefore established as an alternative or complement to explosives. At the tunnel face, mechanical pre-cutting can reduce the blasting burden, and final profiling is often performed hydraulically.
Natural stone extraction
In the production of dimension stone, minimizing microcracks is crucial. While explosives are suitable for mass breakage, hydraulic splitting methods produce calm, straight separation joints and high block qualities. Stone and concrete splitters are a proven option here for obtaining value-adding blocks with minimal waste.
Interior demolition and cutting
In interior areas and confined conditions, the use of explosives is usually not expedient. Instead, concrete demolition shears, multi cutters, and combi shears dominate for the selective separation of concrete, masonry, steel, and composite materials. For metallic tanks and thick-walled structures, a tank cutter can support safe disassembly. This limits dust, noise, and vibrations, and material streams can be separated by type directly at the source.
Distinction and alternatives: hydraulics instead of explosives
Mechanical and hydraulic methods provide a low-vibration and finely controllable alternative to explosives. Stone and concrete splitters generate controlled cracks via spreading forces, rock wedge splitters act deep in the borehole, and concrete demolition shears act on the exposed component. Hydraulic power packs deliver the necessary output; combi shears, steel shears, and multi cutters take over the separation of reinforcement, sections, and attachments. These methods are predestined for inner-city locations, sensitive infrastructure, work near utilities, and selective deconstruction.
Safety, occupational safety, and permits
Explosives are subject to strict regulations on acquisition, storage, transport, and application. Suitable qualifications, approvals, and a documented workflow with hazard analysis are required. This includes cordoning and warning concepts, protective measures against flyrock, vibration and airborne sound monitoring, as well as rules for handling misfires. The information in operating manuals of the means used, in relevant regulations, and the agreements with authorities must be observed. These notes are general in nature and do not replace a project-specific review.
Environmental impacts, emissions, and neighborhood protection
Relevant impacts include vibrations, airborne sound, dust, and flyrock. Coordinated delay sequences, shielding, and suitable working hours can limit emissions. In inner-city deconstruction or near sensitive objects, stone and concrete splitters and concrete demolition shears are often used because these methods are low-vibration and noise-reducing. Continuous monitoring (e.g., vibration measurement) helps ensure compliance with guideline values and creates transparency for local residents.
Planning, quality assurance, and documentation
Professional work planning defines objectives (fragmentation, contour, protected assets), boundary conditions (geology, component build-up), logistical processes, and interfaces to downstream activities such as sorting and haulage. Test areas, measurement-based evaluation, and traceable documentation ensure reproducible results. In combined methods, planning already determines which areas are separated with explosives and which are processed with hydraulic tools such as concrete demolition shears, combi shears, or rock wedge splitters.
Material logistics, storage, and transport of explosives
Explosives and initiation devices are stored separately and securely, safeguarded against unauthorized access and protected from moisture and high temperatures. Transport is carried out in accordance with the applicable dangerous goods regulations. Batch and shelf-life control, proper incoming inspection, and clear inventory management are part of quality assurance. Hydraulic alternatives are likewise subject to requirements for maintenance, leak-tightness, and performance of the hydraulic power packs as well as functional tests on site.
Product relevance in practice: combined methods in deconstruction
In practice, explosives are often used for coarse separation, while fine processing is carried out mechanically. A typical sequence can look like this: large concrete cross-sections are released; subsequently, concrete demolition shears break components to the required size, steel shears cut reinforcement, combi shears process transition areas, and multi cutters separate attachments. Where blasting is not permitted, stone and concrete splitters or rock wedge splitters take over the primary separation. This interplay increases process reliability and the quality of the final result.
Limits of the use of explosives
Explosives reach their limits when the protection of sensitive structures is paramount, when accessibility is restricted, or when legal and organizational efforts outweigh the benefits. In special operations—for example, in facilities with hazardous residues, for critical infrastructure, or in listed structures—stone and concrete splitters, concrete demolition shears, and precise tank cutters are often the first choice. The decision is always made after a comprehensive assessment of risks and boundary conditions.
Linguistic classification and practical usage
In everyday language, “blasting” is often used as an umbrella term for any type of rapid material fracture. Technically, it is important to distinguish between explosive substances, initiation devices, and accessories. Equally important is the distinction from hydraulic splitting and cutting methods, which do not use explosive substances and play a central role in concrete demolition, special deconstruction, rock excavation, and tunneling. For planning, tendering, and execution, clear terminology is helpful so that objectives, risks, and responsibilities are unambiguous.