Tarmac (short for tarmacadam, a portmanteau for tar-penetration macadam) is a type of highway surface, pioneered by John Loudon McAdam in around 1820. Tar is a viscous black Liquid derived from the Destructive distillation of organic matter Macadam is a type of Road construction pioneered by the Scotsman John Loudon McAdam in around 1820 John Loudon McAdam ( September 21 1756 – November 26 1836) was a Scottish Engineer and Road -builder Year 1820 ( MDCCCXX) was a Leap year starting on Saturday (link will display the full calendar of the Gregorian calendar (or a Leap year Strictly speaking, Tarmac refers to a material patented by Edgar Purnell Hooley in 1901. Edgar Purnell Hooley ( 5 June 1860 - 26 January 1942) was the inventor of Tarmac. Year 1901 ( MCMI) was a Common year starting on Tuesday (link will display calendar of the Gregorian calendar (or a Common year starting The term is also used, with varying degrees of correctness, for a variety of other materials, including tar-grouted macadam, Tarvia, bituminous surface treatments and even modern asphalt concrete. Grout is a Construction material used to embed Rebars in Masonry walls connect sections of pre-cast Concrete, fill voids and seal joints (like Asphalt concrete, normally known simply as Asphalt, is a Composite material commonly used for construction of pavement, Highways and

Origins

Macadamized roads were adequate for use by horses and carriages or coaches, but they were very dusty, subject to erosion with heavy rain and did not hold up to higher speed motor vehicle use. Macadam is a type of Road construction pioneered by the Scotsman John Loudon McAdam in around 1820 Methods to stabilise macadam roads with tar date back to at least 1834, when Henry Cassell patented "Pitch Macadam". This method involved spreading tar on the subgrade, then placing a typical macadam layer and then sealing the macadam with a mixture of tar and sand. In Highway engineering, subgrade is the native material underneath a constructed pavement Tar-grouted macadam was also in use well before 1900, and involved scarifying the surface of an existing macadam pavement, spreading tar and re-compacting. Hooley's patent for Tarmac involved mechanically mixing tar and aggregate prior to lay-down, and then compacting the mixture with a steam roller. A steamroller (or steam roller) is a form of Road roller &ndash a type of heavy construction machinery used for levelling surfaces such as roads or airfields The tar was modified with the addition of small amounts of Portland cement, resin and pitch. Portland cement is the most common type of Cement in general usage in many parts of the world as it is a basic ingredient of Concrete, mortar, Stucco Resin, not to be confused with Rosin, is a Hydrocarbon Secretion of many Plants particularly coniferous trees. Pitch is the name for any of a number of highly viscous Liquids which appear Solid.

Later developments

As petroleum production increased, the by-product asphalt became available in huge quantities and largely supplanted tar due to its reduced temperature sensitivity. Petroleum ( L petroleum, from Greek πετρέλαιον, lit Asphalt ( is a sticky black and highly viscous liquid or semi-solid that is present in most crude Petroleums and in some natural deposits sometimes termed asphaltum The Macadam construction process also became quickly obsolete due to its high manual labour requirement; however, the somewhat similar tar and chip method, also known as bituminous surface treatment (BST), remains popular.

While the specific Tarmac pavement is not common in some countries today, many people use the word to refer to generic paved areas at airports, especially the airport ramp or "apron", near the terminals despite the fact that many of these areas are in fact made of concrete. An airport is a location where Aircraft such as airplanes, Helicopters and blimps take off and land The airport ramp or apron is part of an Airport. It is usually the area where Aircraft are parked unloaded or loaded refueled or boarded An airport terminal is a building at an Airport where passengers transfer between ground transportation and the facilities that allow them to board and disembark from Airplanes Concrete is a construction material composed of Cement (commonly Portland cement) as well as other cementitious materials such as Fly ash and Slag This term seems to have been popularised when it became part of the news lexicon following live coverage of the Entebbe hijacking in 1976, where "Tarmac" was frequently used by the on-scene BBC reporter in describing the hijack scene. Operation Entebbe, also known as the Entebbe Raid or Operation Thunderbolt, was a counter-terrorism hostage-rescue mission carried out by the ^[1] The Wick Airport at Wick in Caithness, Scotland is one of the few airports that still has a real Tarmac runway. Wick Airport is located north of the town of Wick in Caithness at the north-eastern extremity of the mainland of Scotland. Wick ( Inbhir Uige in Gaelic) is an Estuary Town and a former Burgh in the north of the Highland council area Geography Caithness extends about 40 Miles (64 Kilometres) north-south and about 30 miles (50 km east-west Scotland ( Gaelic: Alba) is a Country in northwest Europethat occupies the northern third of the island of Great Britain.

Patents

• Hooley, E. Purnell, U.S. Patent 765,975 , "Apparatus for the preparation of tar macadam", July 26, 1904.

References

See also

• Asphalt concrete
• Pavement (material)
• Tarmac (company)