Particle measurement test describes the systematic detection of dust and fine dust in the air. On construction sites, in deconstruction, and in natural stone extraction, mineral dust arises from concrete, mortar, rock, and metal processing. For planning and executing work with concrete demolition shear, rock and concrete splitters, or in tunnel construction, understanding dust exposure is important. It helps assess health risks, steer dust suppression, and document project outcomes in a traceable way. Darda GmbH classifies particle measurements as part of careful work preparation without altering the character of the measurement as an objective, methodologically sound stocktaking.
Definition: What is meant by particle measurement
Particle measurement refers to the determination of size, number, and mass of airborne particles. Common indicators include PM10, PM2.5, and PM1 (fractions by aerodynamic diameter), distinguishing between inhalable, thoracic, and respirable. In addition, mass-related concentrations (for example mg/m³, µg/m³), number concentrations (particles/cm³), or surface-specific metrics are determined. In construction and deconstruction, one often distinguishes between emission measurement near the source (e.g., at a concrete demolition shear), immission measurement in the surroundings (e.g., at the property boundary), and workplace-related measurement at breathing zone height. The goal is the objective assessment of peak loads and averages as well as the effectiveness control of dust suppression measures.
Measurement methods and metrics in construction, demolition, and extraction
Gravimetric, optical, and condensation-based methods are used for particle measurement. Gravimetry determines dust mass via filter sampling with cyclonic pre-separators or impactors for defined fractions. Optical methods (light scattering, nephelometry, optical particle counters) provide time-resolved data on size and number. Condensation particle counters capture very fine particles at high number concentrations. The choice of method depends on the material (concrete, natural stone, reinforcing steel), the working technique (e.g., concrete splitter, concrete demolition shear, hydraulic shear), and the objective of the measurement (peaks, averages, trends). Important metrics are short-term peaks, time-weighted averages (TWA), percentiles, and the distribution across size classes. Quality assurance includes calibration, zero and span checks, sample recovery, and correct documentation of flow rate, temperature, and humidity.
Dust sources with concrete demolition shear and concrete splitter
Mineral dust is generated when the matrix of concrete or rock is mechanically stressed. Crushing with a concrete demolition shear creates fracture surfaces and abrasion on aggregate and matrix. When splitting with a concrete splitter, crack formation and controlled separation along the tensile zone dominate. These different material stresses generally produce different particle size distributions. Splitting processes often lead to fewer very fine fractions, while crushing methods can generate more fine content. Actual emission, however, strongly depends on strength, moisture, aggregates, reinforcement content, process parameters, and the guidance of the tool.
Influence of the processing technique
- Concrete splitter: Crack initiation and propagation with low frictional abrasion, often lower fine dust formation, strongly dependent on borehole geometry and substrate moisture.
- Concrete demolition shear: Shear and compressive loading; fine fraction influenced by opening and closing speed, cutting edge condition, and springback in the structural element.
- Hydraulic shear and Multi Cutters: Primarily metal abrasion and splinters; mineral dust fractions arise mainly when separating composite materials (concrete/steel).
- Tank cutters: Metal particles and aerosols; mineral dust fractions can occur at anchorages or in work near foundations.
- Hydraulic power pack: Influences process steadiness and thus the temporal dust emission, but does not itself generate mineral dust.
Planning the particle measurement on the construction site
A robust measurement concept is oriented to the work phases and the tools used. For work with concrete demolition shear or a concrete splitter, a combination of personal measurement in the breathing zone and fixed measurement near the source as well as in the background is recommended. This allows source, dispersion, and exposure of individual trades to be separated. Instruments are selected according to the deployment environment: rugged, shock-resistant, and moisture-resistant systems for tunnel construction and deconstruction environments; fine resolution for interior strip-out.
Measurement points and sampling heights
- Source: 1–2 m from the point of processing, at working surface height.
- Workplace: on the person at breathing height; carried along for changing tasks.
- Background: on the wind or ventilation side to delineate ambient load.
Measurement duration and temporal resolution
- Phase-based: start, engagement (e.g., splitting, shear stroke), material removal.
- Long-term: several hours up to per-shift monitoring for trends.
- Short-term: second- to minute-resolution for emission peaks.
Quality assurance and calibration
- Flow control before and after the measurement, zero check, blank runs.
- Filter conditioning and weighing under stable climate conditions.
- Comparison measurements between gravimetric and optical methods for bias correction.
Occupational safety: assessing fine dust exposure
For occupational safety, measured values are compared with generally recognized guideline and assessment benchmarks. The usual approach is to combine personal gravimetric measurement for mass concentrations with time-resolved optical measurement for peaks. This captures both shift-long exposure and short-term loads. Statements on limit and guideline values must always be general and non-binding; specific requirements may vary by country, industry, and task. Results should be interpreted in relation to the specific methods used (e.g., concrete demolition shear, concrete splitter) in order to derive targeted technical and organizational measures.
Personal and fixed measurement
- Personal-worn: represents individual exposure, helpful for mobile activities and varying distances to the source.
- Fixed: shows sources and dispersion, allows evaluation of protective enclosure, negative pressure containment, or water spray.
Emissions in tunnel construction and rock excavation
In tunnel construction and rock excavation, limited air volumes, varying humidity, and restricted visibility prevail. Here, the combination of rugged, time-resolved instruments and careful sample logistics is decisive. Splitting procedures can reduce fine dust formation compared to percussive methods, provided process control is calm and material handling is organized with low dust. Measurement concepts consider the flow of tunnel ventilation, working distances, rebound of fragments, and placement of devices outside direct splash zones, with practices aligned to rock demolition and tunnel construction.
Data analysis and reporting
Raw data are checked for plausibility, zero drift, and outliers. This is followed by aggregation by work phase: positioning the concrete demolition shear, the actual shear stroke, release and removal; or drilling, setting, and splitting with the concrete splitter. Important evaluations are time series, percentiles, TWA, and peaks linked to specific actions. Transparency arises by linking measured values with the site diary, photos from a safe distance, and machine logs of the hydraulic power pack (e.g., pressure and cycle information), where available. Reports should clearly state measurement uncertainty and the limits of transferability.
Measures for dust suppression and their metrological control
The effectiveness of dust suppression is pragmatically verified with before-and-after measurements. Identical work phases with identical tool handling are repeated. Especially with concrete demolition shear and concrete splitter, the cutting/splitting sequence, accessibility, and material preparation influence dust release. Low-dust workflows combine technical, organizational, and personal measures.
Water, extraction, material preparation
- Water spray at the point of engagement reduces fine dust; dose so that visibility and electrics are not impaired.
- Point extraction near the source; secure hose routing against kinks and leaks.
- Pre-wetting of cutting and splitting lines; remove loose dust nests before shear strokes.
Tool selection and process control
- Work splitting first, then crushing: initiate separation cracks, then shear in a targeted way.
- Continuous rather than jerky engagement; sharp cutting edges and intact jaws on the concrete demolition shear.
- Hydraulic power units with stable delivery to avoid unnecessary peak loads.
Measured values show the effect of these measures directly: declining peaks and lower averages confirm effective implementation. Increases indicate changed material, tool wear, or unfavorable process sequences.
Environmental aspects and neighborhood protection
Immission measurements at sensitive points (e.g., building façades, property boundaries) support neighborhood protection. Time-resolved measurements help separate construction site emission and background. Low-dust workflows with concrete demolition shear and concrete splitter, complemented by protective enclosure and cleaning, reduce deposits on traffic areas and entries into drainage. Statements on environmental requirements should always remain general; specific conditions may vary by project, location, and permitting situation.
Typical measurement errors and uncertainties
Measurements are only as good as their quality assurance. Typical errors are humidity effects on optical devices, losses of coarse particles in intake hoses, incorrect cut-off curves on cyclones, electrostatic effects on filters, and non-representative measurement points. Good practice includes short intake paths, sufficient stabilization before weighing, on-site calibration checks, parallel measurements of different methods, and clear chain-of-custody protocols. Uncertainties are reported to keep decisions robust.
Practical examples: application-oriented measurement concepts
The following scenarios show how measurement strategies can be adapted to the application area without providing case-specific consulting.
Concrete demolition with a concrete demolition shear
- Measurement objective: assessment of peaks during shear strokes and rework.
- Setup: personal gravimetry (shift) plus optical source/background.
- Measure check: comparison of peaks with and without water spray and with modified stroke sequences.
Concrete splitter in natural stone extraction
- Measurement objective: share of fine fractions during splitting in the raw block.
- Setup: optical particle counter near the splitting line, background sensor on the windward side.
- Measure check: influence of pre-wetting and borehole geometry on fine dust fractions.
Strip-out: low-dust sequences
- Measurement objective: overall exposure indoors with changing activities.
- Setup: negative pressure containment with fixed monitors; personal filter sampling for selected trades.
- Measure check: effectiveness of protective enclosure and point extraction during combined use of concrete demolition shear, hydraulic shear, and Multi Cutters.
Material- and process-dependent specifics
Concrete with a high fine cement content, dense aggregates, or dry surfaces shows different emission profiles compared to moist, carbonated, or fiber-reinforced concrete. Natural stones vary by bonding and grain. Process factors such as feed, pressure, stroke rate, jaw geometry of the concrete demolition shear, as well as drilling pattern and spreading pressures with the concrete splitter shape the particle distribution. Measurements should reflect these differences and account for them in the evaluation.
Integration into project management
Particle measurement test is not an end in itself. It serves process control, effectiveness checks, and documentation for project stakeholders. Darda GmbH recommends integrating measurements early into work planning: goal definition, method selection, responsibilities, measurement points, data management. This way, insights from the measurement feed directly into the choice of tools (e.g., concrete demolition shear, concrete splitter), the sequence of work steps, and dust suppression measures.