Asphalt is a black brown complex mixture composed of hydrocarbons of different molecular weight and non-metallic derivatives, is a kind of high viscosity organic liquid, mostly in liquid or semi-solid petroleum form, the surface is black, soluble in carbon disulfide, carbon tetrachloride. Asphalt is a kind of waterproof, moisture-proof and anticorrosive organic cementitious material.
Asphalt can be mainly divided into coal tar pitch, petroleum asphalt and natural asphalt three kinds: coal tar pitch is a by-product of coking. Petroleum bitumen is the residue of crude oil distillation. Natural bitumen is stored in the ground, and some form mineral layers or accumulate on the earth's crust. Asphalt is mainly used in coatings, plastics, rubber and other industries as well as pavement.
