Asphalt must be liquified before it can be pumped through pipes, mixed with stone aggregates, or sprayed through nozzles. Heating is one way to liquify asphalt for constructio
…n purposes. But when asphalt cools, it becomes a semisolid material. There are other ways to liquify asphalt for construction operations. One way is to emulsify it with an emulsifying agent and water. In the emulsification process, warm asphalt is mechanically milled into very very small globules (5-10 microns and smaller) and dispersed into the water treated with emulsigying agent. The emulsifying agent keeps the asphalt globules apart from one another and suspended in the water which allows the asphalt to be used at room and cold temperatures. After the emulsified asphalt is sprayed onto a surface or mixed with aggregates the water evaporates and leaves only the asphalt residue behind to cement the aggregates together or waterproof the surface it was sprayed on. (MORE) 
