Building Demolition and Recycling
Building demolition as a concept is as old as the concept of building itself. All buildings, with a few exceptions such as the pyramids, or Stonehenge, have a life-span that will end at some time.
As more and more building land is required in the UK, so more attention has been paid to brownfield sites. These can be either re-modelled and re-vamped, or demolished.
Industrial sites, redundant factories and out of date housing can be demolished in various ways.
The method of demolition will vary with the location of the building, the original type of construction materials used, and what will happen to the debris itself.
Demolition Using Explosives
Implosion may be used, that is, the use of explosives, generally on larger buildings. The charges detonate inwards, taking out the vital structural supports, without which the weight of the building brings itself down, collapsing in on itself.
This is a highly specialised method, carried out on larger structures such as tower blocks or cooling towers at power stations.
More commonly, mechanised demolition is used. Relatively tall structures will usually be started by a high reach arm.
A high reach arm is a demolition arm consisting of three sections, or a telescopic boom, with a tool at the reach end, interchangeable with the types of construction material to be broken. Shear attachments are typically engaged to undo structural steel components, and hydraulic hammers to break concrete.
The base of the arm is set on a crawler type body strong enough to allow safe travel over building spoil.
There will be other machinery at ground level to move, or to crush, concrete or masonry blocks into manageable units.
Bulldozers or back hoe loaders may be used in lower level demolition, with attachments allowing them to ram buildings. Skid loaders may be employed to move material from the impact areas.
Recycling of materials from demolition is becoming a mainline business, and some demolition sites specialise in reclamation.
Reclamation differs from recycling. Recycling is the processing of materials, allowing them to be used as ingredients for reuse in the building industry.
Reclamation is the re-use of the constituents of previous construction, perhaps refinished or shaped, but not reprocessed and retain their original form.
Demolition sites today often use both reclamation and recycling to utilise the economic values in the spoil material, and reducing the amount of waste taken to landfill.
Concrete can be crushed and used as an ingredient in new concrete products. It is used extensively in bases for road construction.
Steel can easily be reprocessed, and used again in different forms in construction.