Demolition works always involve many risks and challenges that must be taken into consideration by taking preventive and safety measures before commencing the demolition process.
Each structure has its life span determined by the engineers and designers, so when the building reaches this age, it becomes a danger to its occupants or the facilities adjacent to it.
Therefore, it was necessary to develop an appropriate plan and determine the means used to carry out the demolition work, which will be identified in this article
What are demolition works?
They are all operations that would break, sabotage, or destroy any structure or building in whole or in part for many reasons, including its expiry for service, design change, renovation, or structural damage to the building.
The removal work is carried out on the basis of prior planning by the demolition contractors, and is also subject to supervision by the competent authorities, as it involves complex and dangerous operations, so the ordinary person cannot carry out these operations alone.
so it is necessary to talk about the challenges resulting from the demolition of buildings and facilities and how to prevent them.
Risks and challenges arising from demolition work
1- exposure to lead
The danger arises from lead in the form of toxic dust or toxic fumes resulting from cutting and burning steel works painted with lead-based painting materials.
The possibility of workers being exposed to a high concentration of lead that exceeds the permissible limit of lead (50 µg/m3). Appropriate protective equipment (respirators) must be provided.
2- Exposure to asbestos
Asbestos dust and fibers are generated when carrying out any demolition work that contains asbestos layers of paint, thermal insulation materials, fire-resistant partitions, or asbestos cement panels.
In this field, before starting any demolition project, all precautionary measures were taken, including the use of appropriate respiratory protection equipment (masks with high-efficiency filters).
(HEPA Filters – High-Efficiency Particulate Air Filters)
3- Exposure to dust containing silica
Exposure to dust containing silica, workers at demolition sites may develop silicosis if they are exposed to high doses of this dust. Therefore, it is necessary to use appropriate protective equipment (respirators) while working on demolition sites.
Entering confined spaces
Tanks or other containers may contain toxic gases or fumes. Also, the oxygen level is low inside these confined spaces, which poses a great danger to the lives of workers if they enter them.
Therefore, it is necessary to ventilate these places and test the atmosphere in them before allowing workers to enter them or before permitting them. With demolition (the need to use the appropriate entry permits with taking all necessary precautions and appropriate rescue procedures).
The operation of various demolition equipment results in high levels of noise that may well exceed the average level allowed for exposure for eight hours per day (90 dBA).
Therefore, tasks that may expose workers to doses of noise higher than the permissible level must be identified and appropriate ear protections should be provided that reduces the noise level to less than the permissible limit.
It is also necessary to install appropriate signs to warn of the dangers of noise and to alert workers to the necessity of using protective equipment.
Equipment that operates by compressed air produces vibrations with high rates that exceed the permissible limit of (2.8 M/S2) within 8 hours, which may cause the workers to have stiff fingers.
These risks can be reduced by using vibration-resistant gloves and choosing the equipment that results in a Lower level of vibration.
Types and equipment for demolition work
There are many methods of demolition in proportion to the nature of the structure to be removed, whether it is completely or partially.
Therefore, it is necessary to ensure the validity of the equipment and machinery operating on the site and to obtain certificates from specialized offices in this matter, with a commitment to carry out the necessary maintenance of the mechanisms during demolition work.
The methods of demolishing structures and facilities are divided into three sections:
1- Manual demolition
Only hand tools are used in this type of demolition, with lifting equipment used to catch large parts of the structure during the cutting process and for the purpose of lowering the cut parts and other debris.
In all surface demolitions, the necessary protection of the edges must be provided whenever possible, or safety belts must be used.
2- Demolition by machines
In this type, excavators and remote robotic equipment are used in demolition due to the inability of the human element to carry out these tasks, such as the difficulty of reaching confined places or to save time and effort in demolition work.
3- Drop/pull with steel rope
By connecting the demolition ball to the crane and starting to attract the structure with steel ropes tied tightly, the demolition is done by a collision when dropping.
Steps to carry out demolition works
In order to complete the implementation of building demolition operations, procedures and standards must be passed to reach safety, so we will learn about the most important steps taken before and during the start of work.
It is intended to study and analyze the structure and its surroundings and its special features.
It is divided into two parts:
The first: is a building survey: in which the types of materials used in construction, the state of sewage, and the basic problems related to noise, dust, vibrations, and traffic are known.
Second: Structural survey: in which the condition of the entire building is studied and the structural system is analyzed in design and construction method.
2- Removal of hazardous materials
Some dangerous materials may be produced during the survey process, such as asbestos, for example, so a specialized company must be appointed to treat these materials and remove them from the demolition site before starting.
3- Prepare a demolition plan and complete safety measures
Proper planning is necessary to ensure that the demolition is carried out safely and includes, for example, an engineering survey, provision of insurance, first aid and emergency, provision of protection and appropriate equipment and ensuring its suitability for work, training of employees to use equipment, provision of a safe place for workers and employees and other safety measures that It will facilitate the implementation of demolition work.
Demolition works are subject to strict control by the competent governmental authorities.
These works are not practiced by ordinary persons but are carried out through a demolition company that has a license to practice this profession.
When talking about the demolition of buildings and structures, we at Al-Mrooj Company are ready to present our distinguished experience in safe and sound demolition and to provide any related advice that serves the national and economic interests of the United Arab Emirates.