Development process of asphalt emulsifier
Emulsified asphalt has been studied since the beginning of this century. In the development of the first 40 years, anionic emulsified asphalt is mainly anionic emulsified asphalt, but the particles of this anionic emulsified asphalt have anionic charge. When the emulsion is in contact with the surface of aggregate, the surface of wet aggregate also contains anionic charge, which causes the same type of repulsion. As a result, the asphalt particles cannot adhere to the surface of aggregate as soon as possible.
If the asphalt particles are coated to the surface of the aggregate, the moisture in the emulsion must be evaporated. With the development of modern interface and colloidal chemistry, cationic emulsified asphalt has developed rapidly in the past 20 years. This kind of asphalt emulsion makes asphalt particles with cationic charge, and when they contact with the surface of aggregate, the action of opposites attract, making the asphalt particles adsorb on the surface of aggregate.
Asphalt emulsifier was used in Japan during the earthquake recovery of Tokyo in 1925. Commodity supply began in 1930, and after the war there was a rapid recovery and development. Cationic emulsifiers were first developed in France in 1951. Cationic emulsifiers were used in road construction in the United States in 1957 and were commercialized in 1959. In the 1960s, the Soviet union only used anionic emulsifier. With the development of chemical industry, it began to test some types of cationic surfactant and found that it was feasible to use as road asphalt emulsifier.
In 1972, cationic emulsifier alkyl trimethyl ammonium chloride was used as asphalt emulsifier. Since the 1980s, cationic asphalt emulsifier has been newly applied to prevent radioactive contamination of atomic uranium tailings. Long-term stability tests are under way to reduce the seal of 99.9% radon radioactive materials using cationic asphalt emulsifier and cement mortar mixture.
The development and application of cationic asphalt emulsifier started relatively late in China. In 1977, it was successfully developed. Much work has been done to develop cationic emulsified asphalt in China. In 1981, it was listed as a key scientific research project of the ministry of communications, and in 1983 it was listed as an energy-saving application project of the state planning commission and economic commission.
Technical evaluation was conducted by the ministry of transportation in 1985. It is also decided to promote the application nationwide during the seventh five-year plan period. In 1987, cationic emulsifying asphalt promotion conference was held in hangzhou. So far, 14 provinces and cities across the country have already widely used in road construction roads, due to the shortage of raw materials, cationic asphalt emulsifier production well meet the need of practical application, the future is in the domestic new varieties and preparation technology of cationic asphalt emulsifier on strengthening the development and application, improve the level of road construction technology in China, promote the development of national economy.
