It will not have escaped the attention of the road user that most of the roads in the UK are surfaced with asphalt as opposed to its main competitor, concrete, which is a good endorsement of the material's durability and user-friendly nature. In 2003 the market demand for asphalt in the UK was approximately 28 million tonnes used mainly in the road maintenance and new build market. There are other uses for asphalt such as flooring and roofing. These volumes, however, are relatively small compared to the road market and these applications will not therefore be covered in any great detail in this review. Bituminous materials have a long history of use dating back thousands of years. Asphalt, however, has only been around a relatively short time making its debut in the UK around the early 1900s. Edgar Purnell Hooley obtained the first British patent for Tarmacadam in 1902 (a.1) and the following year formed the TarMacadam Syndicate Ltd., in Denby, Derbyshire. It was, however, several years later before it became widely used, aligned with the growth in traffic volumes. Before the advent of bituminous-bound road building materials, roads were constructed of unbound aggregate mixtures that relied on good aggregate interlock for stability.

Asphalt has been used for building roads over the past hundred years and during that time the industry has evolved into a sophisticated sector which is heavily regulated by national and European standards and governed by specifications developed largely by the Highways Agency, usually following consultation with...