Asphalt: Asphalt is the residue after the distillation of crude oil. Depending on the degree of bitumen refining effect, at room temperature into a liquid, semi-solid or solid. Asphalt color black and shiny, asphalt wholesale, with high temperature resistance. Since it has been distilled in the production process to above 400 ℃, asphalt, and thus contains little volatile components, but may still have not been out of the volatile hydrocarbon polymer, these substances are more or less harmful to human health . Among them, the conservation asphalt pavement is usually divided into three categories: preventive maintenance, corrective maintenance, emergency maintenance. These three types of conservation based on road usage can be selected, each of the conservation needs of different types and methods of conservation and maintenance equipment. Three conservation measures the difference is mainly reflected in the length of road conditions and traffic. Of course, no clear boundaries between the three. Asphalt nature | Three levels of chemical quality assurance (Advisory) | asphalt provided by the Jinan Chemical Co., Ltd. three levels. Jinan three ping Chemical Co., Ltd. (www.sanpinghuagong.com) Shandong Jinan, chemical products leader, over the years, the company is implementing the scientific management, innovation and development, the principle of honesty and trustworthiness, and satisfy customer needs. Three-ping Chemical leadership with the staff warmly welcome all inquiries negotiations to create three levels of chemical better future.