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Liquid Asphalt / Emulsions

Emulsified asphalt is asphalt suspended in water. In the emulsification process, warm asphalt is mechanically milled into minute globules, which are then dispersed in water and treated with a small amount of emulsifying agent. Depending on the agent used and other manufacturing controls, emulsified asphalts are produced in several types and grades:

• Anionic -- asphalt globules with an electro-negative charge
• Cationic -- asphalt globules with an electro-positive charge
• Nonionic -- asphalt globules with a neutral charge

The first two are the most commonly used in roadway construction and maintenance. However, nonionics are gaining popularity as emulsion technology advances.

Emulsified asphalt have some distinct advantages over hot asphalt, in that they can be used with cold as well as heated aggregate and with aggregate that is either dry or damp. Its damp aggregate capability gives emulsified asphalt an advantage over cutback asphalt as well.

Emulsified asphalt is used for both road construction and specialty applications. The rapid setting grades are designed to react with aggregate, reverting quickly from emulsion to their asphalt state. These are primarily used in spray applications such as aggregate chip seals, sand seals, and similar surface treatments.