Emulsions are classified by their ionic charge. Cationic emulsions begin with a “C.” If there is no C, the emulsion is usually an anionic. The charge is important when designing an emulsion for compatibility with certain aggregates.
After the charge designation, the next set of letters describes how quickly an emulsion will set or coalesce to a continuous asphalt mass. The standard terms are RS (Rapid Set), MS (Medium Set), SS (Slow Set), and QS (Quick Set).
RS emulsions break rapidly and have little or no ability to mix with an aggregate. MS emulsions are designed to mix with aggregates, and are often called mixing grade emulsions. MS emulsions are used in cold recycling, cold and warm dense-graded aggregate mixes, patch mixes and other mixes.
