Emulsified Asphalts are a mixture of asphaltic cement, water and what?

• A. Mixture of asphaltic cement, water & emulsifying agent
• B. Cut with petroleum solvents
• C. Paving asphalt liquefied by blending with petroleum solvents
• D. Emulsifying agent

Answer: (A)

Emulsified asphalts are formed by dispersing asphaltic cement in water with an emulsifying agent. The emulsifying agent acts like a surfactant, lowering the interfacial tension and giving the asphalt droplets a charge so they stay dispersed rather than coalescing. The water is the continuous phase that carries the asphalt droplets to the pavement, enabling application at workable temperatures. This differs from cutback asphalt, which uses petroleum solvents to dilute the asphalt, and from using an emulsifying agent alone, which cannot create an emulsion without both asphalt and water.