People who regularly work with concrete and masonry drilling and cutting equipment are at high risk of wide range of hazards, like silica dust, saw kick back, toxic exhaust fumes, collapsing walls, blade fracture, electrocution, noise pollution, vibration, slips, falls etc.
These devices are vulnerable to the violent pressures unleashed when the blade of saw jams inside a cut compare to fixed saws. These forces are usually considered as kick-back, pull in or push back and are quite tough and often impossible to control leaving the operator at risk of potentially lethal injury from such an uncontrollable circular saw.
Supervision, instruction, and training are imperative in all concrete and masonry cutting and drilling operations.
Risks and Hazards
Some hazards are quite common and widely witnessed in all types of concrete cutting and drilling, albeit there are some hazards specific to particular types of devices, like:
Push-Back, Kick-back, or Pull-in – These are potentially fatal forces, experienced suddenly and often become difficult to manage. Such conditions can lead to injury when quick cut concrete saws and hand-held are facilitated. It may also wrench the saw from its fittings leaving the saw running on the ground freely.
Obstructions in the Concrete Being Cut – Such obstacle can lead to sudden back-push, back-kick or pull-in movements of the device. They occur when the blade comes in contact with some resistance within the masonry or concrete like from reinforcing steel mesh, bars, or brick ties.
Pinched Cuts – These cuts are witnessed when the material, being cut moves from its place, leading to increased the risk of kick-back etc.
Off-line Cuts – Such situation can make the saw to pinch or bite that may lead to push-back, kick-back, and pull-in movements. These occasions are mostly experienced working with hand-held saws.
Blunt Cutting Edges – This situation is witnessed by relying on a saw blade having a wrong diamond cutting bond. In this situation the bond holds the cutting diamonds together too hard and it leads to delay in cutting process that may lead to the surface diamonds getting blunt.
In this situation, some additional force is applied particularly with hand-held saws, thus catapulting the probability of push-back, kick-back, or pull-in.
Worn, Damaged Saw Blades, or Inappropriate Blade – These can make the blade to vibrate, wobble, shatter, or fragment and often fly off. Blades get disintegrated when force is applied if the blade is dull and when any obstacle is met, which may lead to incorrect cutting groove.
Hazardous Dusts – Such dusts are generated by cutting and drilling equipments that perform dry operations and does not apply water for cooling purpose of the cutting parts to bed the dust.
Cutting Concrete Pipes – For this activity, some special safety procedures should be taken to prohibit the pipe from moving while cutting, specifically when a handheld saw is used. A hazard during pipe cutting can be counted to be the pressure from the increased flange at the pipe-end resulting in closing and pinching the saw blade, resulting in blade shatter or kick-back injury.
Toxic Fumes – In the lack of proper ventilation, petrol motor emissions packed with carbon monoxide and other harmful gases can generate to hazardous levels.
Electric Cables, Water or Gas Pipes – Exposing utility services, particularly in existing structures, can expose the operator to the risk of electrocution, slipping, and open to toxic gases or often explosion too.
Power Cords – When linked with electric-powered cutting devices and other equipments, these may often be damaged. Reservoir of water coolant and suspension could lead to electrocution because of an exposed wire.
Uneven Surfaces – Such situation can enhance the risk of tripping and stumbling of the operator, leading to an unusual movement of the saw resulting in kick-back.
Wet, Slippery Surface – This condition of having slurry or water on floors can make the operator slip and fall.
Vibration – Whole body or arm vibration, if borne for a long time by using drilling and cutting device, may result in nerve, joint and circulatory damage.
Working Alone – Working without any assistance may be a risky bet as this activity would require assistance in case of any urgency or injury.
Noise – High decibel of noise emerged from concrete cutting or drilling is a potential workplace hazard.
It is suggested that an appropriately experienced and qualified engineer should conduct an on-site assessment prior to performing any cutting or drilling of a pre-tensioned or post-tensioned structure of a building or structure.
The evaluation report should be documented and presented before the person contracted to perform the task.
Identify Hazards and Control Risks
Identifying the hazard and assessing the risk for every type of concrete cutting and drilling tasks is required to develop and implement control measures for every piece of equipment and every job.
Control measures should include safe working tactics, should be conceptualized in consultation with everyone at the workplace, including workers, employers, managers, supervisors, in charge of workplaces, contract people, and health and safety representatives.
When working with such hazardous equipments, it is essential to follow certain laid down safety measures. Some of the most successful safety rules include – control measures must be daily reviewed and analyzed by communication and consultation, safety and health committee meet ups, regular check of equipment and work safety measures, keeping track of accident and near-miss records, injury and lost time data; and repair and maintenance reports.