Petroleum bitumen can be classified according to the following system: the production process (1) distillation: atmospheric distillation of crude oil is separated gasoline, kerosene, diesel and other light distillates, bitumen, and then by vacuum distillation (residual pressure 10 ~ 100mmHg) When separated vacuum distillate, the remaining residue consistent with road asphalt specifications can directly produce bitumen products, resulting bitumen, also known as straight asphalt, it is the main method of production of road asphalt. (2) Solvent precipitation method: non-polar low molecular weight alkanes solvent residue in the components have different solubility decompression, Shandong asphalt, utilizing solubility difference can be achieved separation of components, which can be from vacuum residue adverse nature of asphalt removal of components, bitumen prices, production to meet the specifications of asphalt products, which is a solvent precipitation method. In the early 20th century, along with engineering material prices to continue to decline, asphalt show more sense. In 1907, the first asphalt members in the United States put into use. In 1914, in order to get a better index of refraction, people in Berlin for the first time to see the racing lane asphalt pavement, followed by asphalt in road construction in 1923, the dam of asphalt seal is applied. In order to accelerate the construction progress and improved member in 1924 in California for the first time the road was completed acceptance testing. In order to determine the quality of building materials, the next few years, many testing procedures to be developed. These programs are still valid today applied traffic engineering research, design and concrete construction were. In 1936 the development of the invention the Ring und Kugel-Versuch, one year after the invention of Brechpunkt nach Fraa & szlig, 1941 invented the Marshall test (Marshall-Test). Through special additives, 1950, bitumen wholesale, at a low temperature state Asphalt possible (referred to as cold asphalt). In order to determine the appropriate thickness of asphalt structure, in 1959, developed in Austria by non-intrusive research and isotope method has been successfully verified. In order to make the airport runway in use as soon as possible, in 1963 there has been a dry asphalt construction technology in the UK. 1968 shortly after the first occurrence of Ma Ti asphalt construction. In the 1970s the United States began the practice of recycling asphalt. For better sealing effect, in 1979, it began using asphalt dump project. Asphalt use asphalt _ _ Chemical offers three levels by the Jinan Chemical Co., Ltd. three levels. Jinan three ping Chemical Co. (www.sanpinghuagong.com) strong, credible, in Jinan, Shandong chemical products industry has accumulated a large number of loyal customers. The company better work attitude and constantly improving innovative ideas will lead three levels of chemical into the brilliant and you work for a better future!