Classification and production of emulsified asphalt
August 17, 2022
The so-called emulsified asphalt refers to the thermal melting of asphalt, which is dispersed in an aqueous solution containing an emulsifier in the form of fine droplets under the action of mechanical shearing to form an oil-in-water asphalt emulsion. Compared with ordinary bitumen and modified bitumen, emulsified bitumen can flow freely at normal temperature, without heating during use, and is easy to store, transport and use. It has been used in auxiliary layers such as pavement sealing layer, sticky layer and permeable layer, and has also played a huge role in cold recycling of waste mixtures.

Emulsified asphalt can be divided into ordinary emulsified asphalt and modified emulsified asphalt according to the performance of residual asphalt.


Among them, ordinary emulsified asphalt refers to emulsified asphalt prepared from ordinary asphalt (base asphalt). Modified asphalt can be divided into two categories according to the production process: emulsification first and then modification, first modification and then emulsification. The former is to prepare ordinary emulsified asphalt first, and then mix the asphalt emulsion with the rubber latex; the latter prepares the modified asphalt first, and then emulsifies the modified asphalt to prepare the asphalt emulsion.
The production process of emulsified asphalt is relatively simple. The emulsified asphalt can be obtained by pouring the asphalt that has been heated to a suitable temperature and measured together with the soap liquid into the emulsifier.
Regardless of the process, the most important part of producing emulsified asphalt is the emulsification process. The key equipment in this process is the emulsifier, which is usually dominated by colloid mills in China.
As the key material in the production of emulsified asphalt, emulsifier is essentially a surfactant. According to the different types of emulsifier ions used, emulsified asphalt can be divided into anionic emulsified asphalt, cationic emulsified asphalt, zwitterionic emulsified asphalt, and non-ionic emulsified asphalt. At present, cationic emulsified asphalt is usually used in the road industry, and anionic emulsified asphalt is often used in the construction waterproofing industry.