asphalt

asphalt , brownish-black substance used commonly in road making, roofing, and waterproofing. Chemically, it is a natural mixture of hydrocarbons. It varies in consistency from a solid to a semisolid, has great tenacity, melts when heated, and when ignited will burn with a smoky flame leaving very little or no ash. It is found in nature in deposits called asphalt lakes. Natural asphalt was probably formed by the evaporation of petroleum. Asphalt is obtained as a residue in the distillation or refining of petroleum. This is its important commercial source. It occurs also in asphalt rock, a natural mixture of asphalt with sand and limestone, which when crushed is used as road-building material. Asphalt is also used in the manufacture of paints and varnishes, giving an intensely black color.

asphalt XIV. Early forms aspalt(oun), ult. — late L. asphalton, -um — Gr. ásphalton, -os; later asphalt(e) reproduces the F. asphalte.

asphalt Naturally occurring black or brown semi-solid bitumen, used mainly for road covering and roofing. Asphalt deposits occur in many parts of the world, including Trinidad, Venezuela, Alabama and Texas. Asphalt also occurs in petroleum, and is now mostly extracted in oil refineries.