Asphalt is composed of different molecular weight hydrocarbons and non metal derivatives of dark brown complex mixtures, is a kind of organic high viscosity liquid, a liquid surface is black, soluble in carbon disulfide. Asphalt is a kind of waterproof, moisture proof and anticorrosive organic cementitious material. Asphalt can be divided into three kinds of coal tar pitch, petroleum asphalt and natural asphalt: the coal tar pitch is a byproduct of coking. Petroleum asphalt is the residue after the distillation of crude oil. It is in the underground storage of natural asphalt, some form of ore or piled up on the surface of the crust. Asphalt is mainly used in coatings, plastics, rubber and other industries as well as paving roads, etc..