Blasting describes the targeted fracturing of solid material such as concrete, reinforced concrete, or rock by the controlled introduction of energy, in order to convert components, structures, or rock masses into pieces suitable for transport and further processing. In practice, the spectrum ranges from explosive techniques to non-explosive, hydraulic solutions. In concrete demolition, special demolition, rock excavation, tunnel construction, and natural stone extraction, blasting and blasting-related methods are used in combination. Depending on objectives and surroundings, devices such as concrete pulverizers or rock and concrete splitters are employed at different process stages.
Definition: What is meant by blasting
Blasting is understood as the controlled disassembly of massive material by the sudden release of stresses along artificially created zones of weakness. This can be carried out using explosive techniques (for example with explosive charges) or in a non-explosive manner, such as by hydraulic splitting. The goal is defined fragmentation that takes into account geometric specifications, vibration and emission limits, as well as structural and safety boundary conditions. Blasting serves to loosen, separate, pre-break, or deliberately reduce component thicknesses and volumes, often as a preparatory step for mechanical follow-up processing.
Methods and operating principles of blasting
Blasting is based on generating and directing tensile stresses that load the material beyond its strength along desired separation planes. The selection and design of the method depend on material properties (strength, matrix, reinforcement), environmental constraints (vibration, noise, dust), and logistical objectives.
Explosive blasting
With explosive techniques, energy is released in a very short time to initiate cracking and fragmentation. The effect can be controlled via drilling pattern, charge arrangement, delay, and shielding. In urban areas and sensitive structures, vibration and emission limits take priority; often the volume is reduced first or components are shielded so that the effects of shock and pressure waves remain controlled.
Hydraulic splitting as a non-explosive alternative
In hydraulic splitting, rock and concrete splitters as well as rock splitting cylinders generate controlled tensile stresses in the borehole via wedge- or cylinder-shaped pressure bodies. The material breaks along defined axes, fragment size is highly controllable, and vibrations and airborne sound remain very low. This method is particularly proven in inner-city concrete demolition and special demolition, during strip-out works, and in rock excavation and tunnel construction when regulations constrain explosive methods.
Combined methods
In practice, methods are combined: pre-drilling and splitting reduce cross-sections and stress states, after which concrete pulverizers, combination shears or multi cutters undertake structured disassembly. In this way, vibration, dust, and back-effects on adjacent structures can be minimized while optimizing logistics for removal.
Fields of application and typical objectives
Depending on the area of use, target geometries, environmental constraints, and equipment differ:
Concrete demolition and special demolition
Massive foundations, bridges, or bunker structures are often reduced volumetrically first. Concrete pulverizers separate reinforcement and concrete in the course of dismantling, while rock and concrete splitters pre-break components along defined lines. This facilitates low-dust, low-vibration step-by-step dismantling.
Strip-out and cutting
In buildings with confined space conditions, non-explosive methods are essential. Hydraulic splitting systems create separation joints before multi cutters or combination shears process lines, beams, and mixed constructions. Controlled removal supports clean material separation for recycling.
Rock excavation and tunnel construction
In rock, pre-fragmentation facilitates extraction or profiling: splitting cylinders establish defined separation planes, blasting or mechanical processing then handles removal. In sensitive areas, for example near existing structures, non-explosive methods are used to meet vibration limits.
Natural stone extraction
Controlled crack guidance is crucial for block quality and yield. Hydraulic splitting produces smooth separation faces; subsequent work with steel shears or multi cutters squares edges and reduces blocks to transport size.
Special applications
In facilities with elevated safety requirements or in potentially explosive environments, non-explosive solutions are preferred. Tank cutters and shear-based systems complement controlled pre-breaking without introducing ignition sources.
Equipment and tools around blasting
Equipment selection follows the material, accessibility, and emission requirements. Hydraulics provide the energy in many projects; hydraulic power units feed the end tools and enable modular setups.
Rock and concrete splitters
Splitters and rock splitting cylinders work gently on the material and generate defined cracks with high repeatability. Typical tasks include pre-breaking foundations, loosening rock in excavation pits, and creating separation joints in deconstruction.
Concrete pulverizers
Concrete pulverizers combine crushing and cutting action: concrete is crushed, reinforcement is separated. In combination with pre-drilled and tensioned separation planes, they accelerate removal without generating high vibrations.
Combination shears and multi cutters
These tools cover different material types, such as mixed constructions of concrete, masonry, and steel. They are positioned in the follow-up process to blasting or pre-breaking and support structured dismantling.
Steel shears and tank cutters
Steel shears cut profiles, beams, and reinforcement. Tank cutters are used where thermal cutting methods are not permitted due to fire and explosion protection.
Planning, safety, and regulatory framework
Blasting and blasting-related methods require careful planning. The protection of people, adjacent buildings, and the environment takes top priority. Depending on the method, qualifications and permits are necessary; compliance with applicable legal requirements lies with those executing the work.
Essential planning steps
- Survey of existing material, reinforcement, stresses, and accessibility
- Definition of vibration, noise, and dust limits
- Method selection (explosive, hydraulic, combined) depending on constraints
- Protection and shielding concept, traffic and neighborhood management
- Measurement and monitoring concept for vibration, airborne sound, and dust
Occupational safety and environmental protection
Personal protective equipment, barriers, safe working distances, and controlled load paths are mandatory. For dust and noise, technical, organizational, and, where required, personal measures are combined. Water and soil protection must be considered in planning and execution.
Vibration, noise, and dust: control and mitigation
In the immediate vicinity of sensitive infrastructure, emission limits are often decisive. Hydraulic splitting, the use of concrete pulverizers, and stepwise volume reduction are considered low-vibration methods. Monitoring with suitable measuring technology documents compliance with limits and supports optimization of process parameters.
Practical measures
- Pre-breaking in smaller cycles to reduce energy input per step
- Shielding and enclosure of exposed work areas
- Wet processing to bind dust where suitable for the construction site
- Load management and planned removal to avoid congestion and noise exposure
Selection criteria: when which method makes sense
The decision for blasting, hydraulic splitting, or a combination follows technical, organizational, and regulatory factors:
- Material: strength, matrix, degree of reinforcement, installation situation
- Environment: distance to structures requiring protection, vibration and noise limits
- Accessibility: drillability, space for equipment, component geometry
- Schedule and logistics: cycle planning, fragment size, routing
- Permits and qualifications: legal requirements, documentation of compliance
In inner-city projects with sensitive neighborhoods, non-explosive methods are often preferred. Rock and concrete splitters establish the basis for orderly deconstruction, followed by concrete pulverizers and combination shears.
Process chain: from preparation to post-processing
An efficient sequence reduces risks and costs. Blasting is rarely an isolated step but part of a process chain.
Preparation
Pre-investigations, drilling and separation planning, definition of the removal logic, and site setup form the basis. For hydraulic splitting methods, the drilling pattern is adapted to component thickness and desired fragment size.
Execution
Work is carried out in controlled cycles: pre-break, separate, remove. Concrete pulverizers handle orderly removal and the exposure and separation of reinforcement; multi cutters or steel shears process metallic inserts. Hydraulic power packs feed the tools and must be matched to power and cycle rate.
Post-processing
Checking for residual stresses, inspecting separation faces, and cleaning and sorting material for recycling conclude the section. Documentation and monitoring reports serve quality assurance.
Special scenarios and technical challenges
Heavily reinforced concrete
Reinforcement impedes crack propagation. A combination of splitting to initiate cracks and concrete pulverizers to expose and cut the steel has proven effective.
Confined conditions
In shafts or existing buildings with limited load reserves, low reaction forces are crucial. Hydraulic splitting with small cycle sizes minimizes back-effects.
Protection of historic fabric
Preserving adjacent structures takes precedence: low-vibration methods, stepwise pre-breaking, and precise shear handling are key elements.
Quality assurance and documentation
Quality is reflected in controlled fracture patterns, predictable fragment sizes, and adherence to emission limits. Continuous documentation facilitates verification and optimization.
- Records of drilling pattern, cycle timing, and tool parameters
- Measurements of vibration, airborne sound, and dust
- Photo documentation of separation faces and cut edges
- Feedback from logistics and disposal on fragment suitability
Economics in focus
Economics result from the right combination of methods and equipment. Shorter cycles with lower energy can offer advantages through less rework, fewer damages, and a predictable material flow. Early integration of hydraulic splitting systems often reduces overall time, because follow-on work such as shear and cutting operations proceeds in a more orderly manner.
Legal and organizational notes
For blasting and related methods, different regulations, qualifications, and permits may be relevant depending on country and project. Responsible parties should review the applicable regulations, provide the required evidence, and coordinate measurement and protection concepts with stakeholders at an early stage. The information in this text is general in nature and does not replace project-specific assessment.