Asphalt, also known as bitumen, is a sticky, black, and highly viscous liquid or semi-solid form of petroleum. It may be found in natural deposits or may be a refined product, and is classed as a pitch. Before the 20th century, the term asphaltum was also used. The word is derived from the Ancient Greek ἄσφαλτος ásphaltos.
The primary use (70%) of asphalt is in road construction, where it is used as the glue or binder mixed with aggregate particles to create asphalt concrete. Its other main uses are for bituminous waterproofing products, including production of roofing felt and for sealing flat roofs.
The terms "asphalt" and "bitumen" are often used interchangeably to mean both natural and manufactured forms of the substance. In American English, "asphalt" (or "asphalt cement") is commonly used for a refined residue from the distillation process of selected crude oils. Outside the United States, the product is often called "bitumen", and geologists worldwide often prefer the term for the naturally occurring variety. Common colloquial usage often refers to various forms of asphalt as "tar", as in the name of the La Brea Tar Pits.
Naturally occurring asphalt is sometimes specified by the term "crude bitumen". Its viscosity is similar to that of cold molasses while the material obtained from the fractional distillation of crude oil boiling at 525 °C (977 °F) is sometimes referred to as "refined bitumen". The Canadian province of Alberta has most of the world's reserves of natural asphalt, covering 142,000 square kilometres (55,000 sq mi), an area larger than England....LESS
PHILADELPHIA (AP) — A Philadelphia man who fell into a sinkhole says he was putting traffic cones around it because he was worried about the safety of children playing outside. Eugene Clark tells WCAU-TV (http://bit.ly/2wJ1NiG) he was near the sinkhole Saturday night when the asphalt gave way and he tumbled 10 feet (3 meters) into it.
SAN FRANCISCO (AP) — A 17-year-old boy opened the emergency door of a plane minutes after it landed Tuesday in San Francisco, slid down the wing and jumped onto a tarmac, authorities said. The teen, a U.S. citizen, was flying by himself from Panama City, Panama, to San Francisco and appeared to be in emotional distress during the flight, said San Francisco Airport spokesman Doug Yakel.