Bitumen is a highly viscous, black, organic liquid that is obtained from crude oil. It is the sticky residue left when all of the lighter components of crude oil have been removed during the distillation process. It is similar to tar, which is a residue obtained during the distillation of coal.
Bitumen was once commonly used as a waterproofing sealant in boats and in building construction, but its principle use now is as a binding agent mixed with mineral aggregate for paving roads.
Bitumen is also known as 'asphalt', particularly in North America. In England, the word 'asphalt' usually refers to the paving mixture of bitumen and aggregate, which is known as 'asphalt cement' in North America. In Australia, 'bitumen' is often used as a generic term for any surfaced road, as opposed to un-surfaced or 'dirt' roads. Bitumen-based road surfacing material is also known in some parts of the world as 'tarmac', short for 'tar macadam' , a type of road construction surfaced with a penetrating tar or bitumen sealant.
