What Is an Asphalt Emulsion?
An asphalt emulsion is liquid asphalt cement emulsified in water. It is composed of asphalt, water and an emulsifying agent. The emulsifying agent is sometimes called the surfactant, which is composed of large molecules. These soap molecules are like tadpoles, having a hydrocarbon tail soluble in liquid asphalt and an electrically charged or ionic head soluble in water. The asphalt particles are surrounded by the ionic charge, which causes the droplets to repel each other and stay suspended in the water. All asphalt emulsions are designed to eventually break, or revert to asphalt and water. Some emulsions break by chemically destabilizing the surfactant, others by a simple evaporation of the water. Still others break by a combination of chemical destabilization and evaporation. Todays emulsion manufacturers have many new chemistries available to design the emulsion for the optimal break time and specific use. How Are Emulsions Made? Asphalt cement is the basic ingredient of asphalt emu
