Asphalt

Asphalt, also known as bitumen, is a black, cement-like material varying in consistency at room temperature from solid to semisolid. 

Refined asphalt

It has various other names: pitch, tarmac, blacktop, asphalt concrete, asphalt pavement (US), all mean roughly the same thing. Before the 20th century, the term asphaltum was also used.

Asphalt which is liquid is often called tar. 

Asphalt can be poured when heated to the temperature of boiling water. Its main use is in road construction. Mixed with "aggregate" (sand, gravel, crushed stone, etc.) it makes a good highway surface. 

Asphalt is also used in lining the walls of water-retaining structures such as reservoirs and swimming pools, and in manufacturing floor tiles and roofing felt and for sealing flat roofs.

Natural deposits of asphalt occur in pits or lakes as residue from crude petroleum that has seeped up through fissures in the earth. 

Natural asphalt was used extensively in ancient times. Ancient Babylonians used it as a building material, and it is referred to several times in the Old Testament books of Genesis and Exodus as a caulking material 

Pitch Lake in Trinidad is the world’s largest natural asphalt deposit covering almost 100 acres (0.155 sq ml) 245 feet (75 metres) deep. It is estimated to contain 10 million tons.

Pitch Lake, 2016 By Grueslayer - Own work

The La Brea tar pits (or Rancho La Brea) are a famous cluster of tar pits in central Los Angeles where the remains of prehistoric flora and fauna and complete skeletons of many thousands of large animals have been found. They date mostly from 40,000 to 8,000 years ago.

Almost all of the asphalt used commercially is now derived from petroleum.

In Guam, asphalt is made by mixing ground coral and oil.

Over 3 million tons of asphalt pavement has been recycled and there is over 99% recycling rate for asphalt.

Asphalt is the most recycled material on the planet, with 80% of North American asphalt being recycled annually.