Asphalt

Asphalt (also called bitumen or tarmac) is a material that occurs naturally in most crude petroleums. It is commonly used to build the surface of roads.

Bitumen and asphalt are both naturally occurring minerals that can be crushed and used in various combinations with a binder to create a very durable surface suitable for roads. The name tarmac comes from the original name for the surface—tar-macadam. Macadam referring to the gravel portion of the road, (which were said to be 'macadamized') and tar being used as a unifying coating to harden it.

Bitumen was once referred to as "Jew's pitch," probably owing to its natural abundance along the shores of the Dead and Caspian Seas. Bitumen was also widely used by ancient Sumerians.

Macadamized roads were adequate for use by horses and carriages or coaches, but they were very dusty and turned to mud when it rained. Motor vehicles required a harder surface. In 1851 the road from Travers[?] (Switzerland), where substantial resources of natural asphalt were found, to Paris was covered with asphalt on a length of 78 m. 20 years later Paris was nearly completely asphalted, a soon were other european major cities.

Tarmac was invented when Mr E Purnell Hooley was passing a tarworks in 1901. He saw that a barrel of tar had spilled on the roadway, and in an attempt to reduce the mess, gravel had been dumped on top of it. The area was remarkably dust-free compared to the surrounding road, and it gave Hooley the idea for developing and patenting tarmac in Britain.

He called his company Tar Macadam (Purnell Hooley's Patent) Syndicate Limited, but unfortunately he had trouble selling his product as he was not a very successful businessman. His company was soon bought out by the Wolverhampton MP, Sir Alfred Hickman, the owner of a steelworks which produced large quantities of waste slag. The Tarmac company was relaunched in 1905, and became an immediate success.

Researchers working in the United Kingdom have found way to incorporate ground-up rubber from recycled tyres into bitumen to create a new product that, while still in development, may have great future use. [1] (http://www.cordis.lu/united_kingdom/spotlt3.htm)

• See Also Orimulsion

External link

• Black Stuff (http://www.biffvernon.freeserve.co.uk/black_stuff.htm)