Possible Hazards and Warnings During Concrete Removal

Concrete removal jobs involve different types of hazards. There must be issued a clear and comprehensive warning for possible hazards contractors might face during their job. Here’s a brief list of possible hazards against which the participating contractors are warned.

Trip or Fall Hazards: Contractors are warned to be careful about protruding nails and other sharp objects. Surfaces they are working on must besturdy and not slippery. They also need to wear hard-soled work boots designed to protect their feet against crushing as well as other possible hazards. They must also maintain proper safety by maintaining stable 3-point contact with the ground and also must not stand on the topmost rung.

Chemical Handling Hazards: Contractors must not open or use chemicals with which they are not familiar. Before handling any chemical they must go through the safety data sheets provided by the manufacturers. Even those who are familiar with using chemicals are asked not to mix chemicals for precautionary reasons. Wearing eye protection at the time of handling them is a must.

Noise: Contractors also need to use earplugs to protect their hearing while working around loud equipment like heavy generators or chainsaws.

Head Injury Hazards: While working under low ceilings, or areas with a risk of overhead debris fall, or possible electrical hazards, contractors must use hardhats compliant with ANSI/ISEA 107-2004 standards.

Respiratory Hazards: Due to excessive dust during concrete removal contractors are also asked to use P100/HEPA filtering face masks. They are advised to conduct a seal check every time they use a face mask respirator. This is because apart from dust, other harmful particles like silica, asbestos, laden sand, mold and paint dust may also be present there. Contractors with pre-existing respiratory problems require a medical checkup before taking part in a concrete removal job. In addition, several other precautions are taken to ensure absolute safety while working.

Mold and Biological Hazards: In water damaged buildings, furnishings and materials, there is a high risk of mold contamination. Contractors must use only NIOSH approved respirators while working in those areas. Any porous material that has been wet for more than 48 hours must be removed and discarded. There are also specific instructions about cleaning non-porous surfaces.

Skin Irritation Hazards: When handling fiber glass, concrete or disposables exposed to sewage water, contractors must wear full sleeve shirts to prevent any kind of skin infection and irritation.

Lifting Hazards: The job often includes lifting of heavy loads. Contractors must learn to use safe lifting techniques for preventing any kind of back injury. For safe lifting, contractors should squat and lift. They should avoid bending by their waist when lifting any heavy object. There are also a few additional instructions. They include keeping the load as close to your body as possible; bowing the back and raising the head first while lifting; keeping feet apart; and to avoid jerking or twisting while carrying a load. It is best to wear shoes with no-slip soles. Following these precautionary measures ensures complete safety while working under demanding conditions.

Electrical Safety: Contractors working in cleanup projects and concrete removal jobs must never run a portable generator in closed conditions. The carbon monoxide emitted from the generators is extremely harmful, even fatal in indoor conditions. Shut the generator before refueling. All electric chords must be thoroughly checked for any kind of defect or punches. Contractors are required to use ground-fault-circuit-interrupter or GFCI while working with electrical equipment on a wet surface. They must also maintain a safe distance from grounded power cables. Any electrical equipment coming in contact with water must be checked intensively by a licensed and qualified electrician before switching back on.

Work Zone Traffic: While working near moving vehicles, it is mandatory for the contractors to wear high-visibility clothing and head protection. They must also use proper devices for traffic control to avert any possible accident.

Chain Saw Safety: There is a great potential for injury with this equipment. If not properly trained to handle chain saw or other similar equipment, contractors must abstain from using them. Even those trained to use them must also wear protective gear like hard hats, face shields, clamps and work gloves for maximum safety.

Contractors should be familiar with all the above mentioned hazards and the necessary protective measures before they indulge in concrete removal or other similar activities.

Methods of Concrete Removal/Demolition

There are several conditions that call for concrete removal and replacement. Often, fixing it with a decorative topping or patching the concrete before resurfacing is considered a short-term fix. However, it will soon display the characteristics of damaged concrete that you tried to repair. Under such conditions, concrete demolition and replacement is mostly recommended to ensure that repair work is done from scratch and sturdy enough to last for long.

So, under what circumstances is concrete removal recommended? Typically, it is where there are widespread and deep cracks or the concrete slabs have sunk that you require prompt concrete removal and replacement.

At the same time, concrete slabs that have too much pitting and spalling on the surface or which shows the signs of frost heave are the ones where replacing the concrete can prove to be more economical and reliable than merely resurfacing the entire concrete.

Different Methods of Concrete Removal

Several methods are used in concrete demolition, which is the first and most important step in replacing the concrete in case of excessive damage and building it all over again.

1. Pneumatic and Hydraulic Breakers

Such type of boom mounted or handheld machine tools are frequently used for concrete removal, which involves pavements, bridge decks, and foundations. The level of work achieved by this method typically depends on the strength of the concrete, hammer size of the breakers, working conditions, and amount of steel reinforcing used in the concrete.

Machine-mounted pneumatic and hydraulic breakers can deliver from 100 to 20, 000 foot pounds at just 300 to 800 blows per minute. To ensure that the maximum amount of work is accomplished in a convenient and hassle-free manner, the breakers may also use remote control operation, telescoping boom for maneuverability and reach, and underwater concrete demolition capabilities.

2. Pressure Bursting

Where dust-free, controlled and relatively quiet concrete removal is desired, pressure bursting – mechanical and chemical – is the ultimate choice. Under mechanical pressure bursting technique, the concrete is spilt using a high-power and efficient splitting machine that operates on hydraulic pressure, powered by a motor. In case of chemical pressure bursting, expansive slurry is inserted into a particular pattern of boreholes.

The demolished concrete is then removed easily by hand or crane. Such methods ensure breaking up concrete structures with minimum dust and noise. Under both the methods, holes aredrilled into the structure and lateral force is applied against the same to split the concrete.

3. Dismantling

In this process, concrete elements are cut into smaller pieces using a saw, thermic lance or water-jetting technique, and then the broken pieces are removed by crane. Such a method ensures minimum impact on surrounding structures, emitting lesser dust and noise.

This is a fantastic technique for demolishing a certain portion of the structure, say slabs or walls.

Water-jetting can be used in cutting both contours and straight line and requires usingthe water catching system and abrasive during the cutting process. On the other hand, thermic lance works especially well on steel reinforcing and eliminates dust and vibration.

4. Ball and Crane Method

This is one of the most commonly used techniques in demolishing a building. Here, a ball, weighing up to 13,500 pounds and a crane is used in demolishing masonry and concrete structures. The ball is either swung or dropped onto the structure that needs to be demolished.

However, the process is not suitable for all types of applications and may create a lot of noise, dust and vibration. Only experienced and highly skilled crane operators should perform the concrete demolition method.

5. Explosives

When large volumes of concrete have to be removed, explosives are inserted into a series of pre-determined boreholes, which blast and cause the structure to break into smaller pieces. The method is indeed flexible and versatile pertaining to work output.

However, air blast and vibration may cause damage to the surrounding structure and it is important to take highest standards of safety measures during the process.

Factors to Keep in Mind Before Buying A Wall Mounted Saw

Wall mounted saws are very effective when there is a need to cut concrete at high heights and flat surfaces. Hence, for creating a clean and precise cut, selection of a wall mounted saw packed with modern technical features and featuring a portable design is necessary.  A highly efficient and versatile wall saw, is certainly a worthwhile investment. However, buying a wall mounted saw involves weighing several important factors as discussed below:

Easy Portability and User-friendly Design

An important consideration when buying a wall mounted saw is its design and versatility. It should be lightweight and designed to be portable, and it should also be easy to store when not in use. Read the mounting features very closely and find out the limitations and benefits it offers when it comes to performing concrete cutting on a bench top surface. Mounting features should provide complete flexibility to mount it at various heights. New modular models are easier to install and use, because they have user friendly controls as compared to several models that are bulky and complex to operate.

Power and Efficiency

For optimum performance of the wall mounted saw during cutting, a continuous water supply plays an important role. For this, it is necessary to buy a wall saw with a water cooled electric motor. Wall saws with this feature are very low weight and deliver remarkable power to the spindle. For seamless performance and control, make sure you purchase one which comes with a high performance two-speed water-cooled gearbox

Blade Type

Another important factor to consider is the versatility of the saw. It is easier to make a wide variety of cuts in length with a wall mounted saw that comes with a T-shank jigsaw blade and replacing the blade should be quick and easy.

Type of Motor

When making cuts on materials with different hardness, a variable speed motor provides better productivity since switching to a different speed for each type of material is easy.  These

machines can be used to create a precise cut for door openings, ventilation channels, window openings, dovetail cutting, special cutting, flush cutting and various diverse applications of concrete cutting.

Blade Guard

There are different makes and models of saws available on the market that come with various blade guard settings. Replacing the blade should be relatively easy for contractors. Don’t forget to read the technical specification on the type of blade, which needs to be used with the wall saw. Blades with various diameters should easily fit with the saw to complete cutting in complex places and precise cutting of various material types.

Remote Controller & Display

Don’t forget to check the features of the remote control which gives you complete flexibility in operating the wall saw at a safe distance. Have a look at the technical features and check for the longest distance from where you can operate the saw and examine the size of the LED display. The technical specs are important  in ensuring the you will purchase a machine that will give you complete control over the sawing process as it provides detailed information about the power level, operating time, current, pressure and service period.

Ease of Maintenance

Finally, an important factor to consider is the ease of maintenance of the saw. Unless the saw is long-lasting and resilient, it will not be a good value for money.  For further convenience, it often comes with a dust port that can be attached to the shop vacuum for keeping the space clean and improving visibility. Thus, it should be extremely convenient and simple to maintain and clean a well-chosen wall mounted saw.