warning signs on concrete demolition jobs
MegasawConcrete Removal

How Demolition Machines Offer Improved Safety in Concrete Demolition Jobs

warning signs on concrete demolition jobs

The question of safety is a primary factor for any contractor when planning a concrete demolition job; as it is regarded as being amongst the most dangerous of building operations. Defects or neglect in the initial planning process could result in various injuries to workers or even fatalities. In the past, human error played a significant role in the efficiency of a demolition job, which has in modern times, been nullified by the ever increasing use of demolition machines. The methods and machinery used in a demolition job will vary depending on the site location, the form of the building material and the purpose of the demolition.

A traditional method of demolition is known as the “high reach arm” which is generally employed in the form of a base machine; for example, an excavator, engine, tank, counterweights and a demolition arm. This latter piece of equipment consists of three sections or a telescopic boom and primary tool, such as a crusher, hammer or shears, attached to the base machine. The threshold for defining a high reach demolition is when it reaches a height of more than 20 metres.

Safety in machinery

The inherent safety of demolition machinery is demonstrated by high reach machines having the capability of being equipped with different tools, to meet the demolition needs of various structures. It is a method used on reinforced concrete, steel, masonry and various mixed material content structures, with additional components employed for secondary operations such as material crunching. Several factors influence using this method, including the height of the structure to be demolished, conditions on the site and the structure itself.

Working in the construction and demolition industry involves working in an environment and atmosphere of falling dust, concrete and metal. Therefore, to ensure the safety of operators demolition machinery, such as excavators, are manufactured with various special features. They can include:

  • Front-guards, designed to protect the cabin from falling debris
  • Undercarriage guards that serve the purpose of preventing debris being caught in the crawler

It is the nature of this industry that machines and equipment must be manufactured to an extreme toughness to cope with their task of breaking solidly-built structures, safely and efficiently.

Another traditional and one of the most commonly used methods for certain types of structural demolition is the ball and crane. The operation involves the use of a wrecking ball that can weigh up to 13,500 pounds (6123.497 kilograms) and is used in demolishing concrete and masonry. It is a process whereby the ball is either dropped on, or swung into the structure. The sizes of structures that can be demolished with this method are limited by crane size, working area and various safety factors including the proximity to power lines.

Operator skills and expertise

The nature of this operation calls for the expertise of only highly skilled and experienced crane operators, with additional work needed for the removal of rebar or reo in concrete structures. This is an operation requiring high operational skills and stringent safety precautions, with the control exercised in the swing of the ball being a critical issue. Should the ball miss its determined target then it could cause tipping or overloading of the crane. For any demolition contractor, the safety factor is an inherent part of any operation. From ensuring their machines and equipment are maintained in the best condition, to the employment of only the most qualified and highly-skilled operators, it is a complex operation. The enforcement of safety precautions takes into account ongoing operator training to maintain maximum competency.

Job dictates machinery used

While the demolishing of relatively small buildings and structures is generally a routine operation, which does not require large machinery, any equipment and machines that are used will also be subject to stipulated regulations by local authorities, including those related to safety. In the case of larger buildings and structures that require more extensive machinery and equipment, the method of demolition used will depend on the structure, as will the required safety precautions and features applied. The type of machinery used will also relate to the project personnel and any passing traffic and pedestrians.

The usual machinery and equipment employed in average demolition projects, includes:

  • Bobcats
  • Excavators
  • Hydraulic equipment
  • Mechanical hammers and grabs.
  • Prime movers
  • Semi Tippers and Tip Trucks

Customers benefit from dealing with a construction and demolition company that is well established and boasts an excellent reputation. Confidence is created in the ability of a company and a proven wealth of demolition expertise gained from past projects as well as a strong safety record. It is also essential the company has an in-depth knowledge of local authority regulations, codes, and governing laws. These are all indications that a contractor is conscious of their community responsivities and will conform to, or even exceed, required safety precautions.

warning sign on a concrete demolition site
MegasawConcrete Cutting, Concrete Removal

Protecting Passersby During Concrete Cutting and Demolition Work

warning sign on a concrete demolition site

As reliable and established contractors we are always concerned about the wellbeing of our personnel, the environment and the importance of safety to those in the vicinity of any concrete cutting or demolition work. This is achieved by employing qualified artisans and providing adequate training for them before allocating tasks on job sites. A further aspect is that training must be ongoing, with efficient supervision in every project. Our philosophy is that with highly, efficient personnel, greater and more effective focus will be given to the overall protection and personal safety, thereby minimising risks to passersby as well as occupational hazards. It has always been part of our social responsibility to adhere to proper procedures in waste management and the environmental procedures we carry out.

As concrete cutting and demolition contractors, we are regarded as specialists in the art of destruction. Despite the seeming ease of this occupation to a layperson, it is in fact a challenging expertise that requires careful planning, in order to cut concrete and destroy structures with inherent safety for everyone and the environment. By selecting the appropriate cutting and demolition method, we are able to safely demolish a structure, with trained efficiency and the least amount of disruption to communities.

Traditional and other demolition processes

The crane and wrecking ball is recognised as one of the oldest and most commonly used methods for building demolition, or concrete cutting. We are able to isolate a particular section of a structure, for lowering to ground level for further breaking up or transportation to a dump site. Controlled demolition jobs are completed with the maximum of safety and can generally be achieved with standard concrete sawing techniques and equipment. Cutting concrete with a water jet helps to:

  • Minimise the amount of dust in the atmosphere
  • Reduce vibration
  • Clean up the site with the addition of a water-catching system during the jetting procedure

As and when necessary, blasting methods using explosives are employed which use rapidly expanding gases restrained in boreholes, for the purpose of producing controlled fractures in concrete for easy removal of the material. In general, the blasting methods we use are efficient and provide a safe and secure means of removing significant volumes of distressed or deteriorated concrete materials. Because of the inherent dangers in the handling and use of explosives, blasting is regarded as the most dangerous. It is therefore subject to more stringent controls than other methods of demolition.

Safety is the primary consideration

Whatever process of demolition is used, or size of the job, the safety of those working and passersby within the vicinity of the project, is treated as a matter of primary importance. Among the various key considerations taken into account are:

  • Any potential effects to community services
  • Protecting electricity, gas facilities, water and any other services attached to a structure
  • Appropriately capping facilities as and when necessary
  • Electricity or other lines required to help with the demolition process must be approved heavy-duty materials and be kept adequately and safely protected along an obvious and recognised route
  • Within the structure, the movements of people are catered for with designated routes for example: by way of agreed doorways and stairways; or specifically designed walkways
  • The removal of debris is also planned and catered for, with all horizontal and vertical openings completely blocked, for the purpose of protection from the potential of any falling materials

In any type of business operation, it is generally recognised that the question of safety is the first priority, irrespective of it being a concrete cutting and demolition site, or a normal retail outlet. The safety and wellbeing of personnel and passersby within the vicinity are entitled to conduct their everyday lives in a safe environment which means: there is no allowance made by us for even slight errors.

Equipment criteria

The equipment used for concrete cutting, shaping and demolishing are extremely large and powerful and it must be regarded as critical that all persons in their vicinity are provided with the best available safety and protection from any possible occurrences. Therefore, to meet the demands of communities in which we operate and those of our clients, we have established and proven strategies in place for the provision of a safe and environmentally-friendly concrete cutting and demolition work site operation.

We consider it essential that anyone working with concrete cutting, or even remotely associated with any aspect of demolition work, is made aware of the potential health hazards and take the necessary precautions to avoid serious risks to their health. In the case of passersby, we believe in taking every possible precaution to ensure their safety and protect them to the best of our ability.

MegasawConcrete Cutting

How to Control Dust by Wet Cutting Concrete

wet blade for cutting concrete

Most of us understand that any type of concrete cutting is generally a job that frequently produces clouds of dust. One factor related to this element and possibly not considered to any great extent by most contractors is; the content of those dust clouds. Concrete has a compound known as crystalline silica, which when injected into the atmosphere can present us with some health-related concerns. It’s a common compound found in various elements such as sand, quartz, flint and slate, but does not become a hazard until it is expelled into the air; for example, when concrete is ground, crushed, or cut with a saw.

The methods by which dust in workplaces is suppressed or controlled include wet drilling and water mist drilling to remove and collect dust. In addition, water sprays are employed when sawing dimension stone, using grinding wheels, core cutting, or wetting waste material, when loading trucks, moving broken rock, dumping or stockpiling. The use of wetting agents with water in selected processes is highlighted, with the use of clear water for sprays and mists and using completely wet processing in crushing operations and screening plants.

Cutting concrete methods

Although it’s usual for concrete to be cut with diamond blades, there are different solutions recommended for cutting concrete in various circumstances. For the purpose of significantly reducing the dust factor, concrete is generally cut using a wet-cutting process. If used with sufficient water for the task, it can not only reduce the presence of dust but also helps to keep the diamond blade cool and extend its lifespan. Furthermore, efficiency is improved, keeping in mind that the wet-cutting concrete process can entail deep cuts resulting in continuous work.

Safety procedures

Some safety regulating authorities recommend three procedures for the control of health-threatening silica exposure when cutting concrete. These include:

  • Wet cutting or the use of a hose for watering the working area
  • The installation of exhaust ventilation
  • Dust collection systems attached to equipment

Saws that are used in the cutting of concrete and powered by compressed air or combustion engines employ wet cutting systems, designed to prevent further contamination from dust. The process can involve water being sprayed onto the rotating disk used for cutting concrete to reduce dust emissions, or from a pressurised tank, supplied from the water mains, or one that is portable.

The portable water option

A portable pressurised tank is supplied by many manufacturers of concrete cutting saws. It’s based on a simple bottle, manufactured from polypropylene, containing a minimum of eight litres of water. The way it works is:

  • By the use of tubing, the bottle is attached to two water jets with the volume dispensed and controlled by a valve, also attached to the container
  • The operation is controlled by the construction worker pressurising the tank and releasing the water
  • The suppression of dust is achieved with a minimum water flow rate of approximately half a litre per minute, but a dispensing rate less than that will ultimately and negatively impact on the overall and effective performance

As part of our responsible work commitment, we appreciate that in cutting concrete and when using wet systems or vacuuming to suppress dust during the cutting process, there are opportunities for mishaps. Accordingly, we ensure our workforce is provided with protective equipment such as masks designed to help prevent unnecessary dust inhalation. As established contractors, the use of concrete saws forms part of our daily work tasks and how we cut concrete is considered a crucial decision. It is influenced by the potential impact it will have:

  • On the health of our workers
  • The overall project quality
  • The aesthetics of the materials we are cutting

The majority of concrete saws, handheld or otherwise, are supplied with a water cutting option, with Tub saws including a water pump and handhelds generally having as standard a connection for a household hose.

Environmentally-friendly

The benefit for our customers and the environment is a reduction in dust pollution and less cleaning required in the surrounding structures, which usually attract dust in the atmosphere. There is also an economic and working efficiency gained from the fact that air filters on the concrete saws do not require changing as frequently, due to the water preventing a higher percentage of dust filtering into the air.

Various comparisons have been made between wet and dry cutting concrete. Using water controls regularly with gas-powered concrete saws has been determined as an effective method of reducing the level of dust for project workers, operators and the environment in general. There have been various studies conducted on comparisons between wet and dry cutting, with some findings indicating that using water helped reduced 85% of dust concentration.