Bitumen

Bitumen emulsions are usually dispersion of minute droplets of bitumen in water and are examples of oil-in-water emulsions.The bitumen content can be varied to suit different requirements and is typically between 30% and 70%. The primary objective of emulsifying bitumen is to obtain a product that can be used without the heating normally required when using cutbacks and paving grade bitumen.In the manufacture of bitumen emulsions, hot bitumen is sheared rapidly in water containing an emulsifying chemical (emulsifier). This produces very small particles of bitumen (the dispersed phase) dispersed in water (the continuous phase). The bitumen particles are stabilized in suspension and do not readily coalesce due to the presence of the emulsifier, which is concentrated on the surface of the bitumen particles.