Tarmac is a brand name owned by Tarmac Building Products Ltd, but the word ‘tarmac’ is commonly associated with road and airport surfaces.
The invention of Tarmac is down to two British men. John McAdam developed a surfacing method based around layering and compacting stones in decreasing sizes from base to surface. The macadam method uses the natural earth as a base and the incremental sizing of stones to form its structure.
McAdam had a team of workers breaking stones with hammers into two approximate size levels. The base layer would be made of rock fragments of up to 7.5cm in diameter, whilst the upper section would have an aggregate mix no larger than 2cm.
The advent of motor vehicles caused a problem of dust being lifted from the road surface. The dust would be formed by the compression of rock segments under the weight of the vehicles, and then the air pressure formed by the vehicles passing at speed would lift the dust away from the road.
The invention of Tarmac
Edgar Hooley discovered a way to increase the strength of these road surfaces when in 1901 he noticed that a spillage of tar on a road in Derbyshire had been covered up with waste iron slag from a local furnace. The result was a much smoother, stronger and more consistent surface. This accidental discovery spawned a road surfacing revolution.
This new tar macadam material would be known as Tarmac, which Hooley trademarked in 1903. Also in 1903 the first tar macadam road was laid. A five-mile stretch of Radcliffe Road in Nottingham showcased the material’s ability to withstand years of use, and Hooley later sold the company to the owner of a steelworks with a plentiful supply of the iron slag.
Nowadays the term ‘tarmac’ is often used to refer to asphalt concrete, even though it is not made using tar and macadam. Asphalt is actually a petroleum-based substance also known as bitumen, used instead of tar to bind the aggregate to itself and to the underlying surface. However, it is Tarmac that is so readily associated with road surfacing.
Tarmac can be cut using a floor saw by Norton Clipper with laser welded diamond blades. For advice on the eight blade for the task at hand you can contact Construction Equipment UK on 0116 2641077.