contact with quartz-rich aggregates. They are substituted by cationic emulsions achieving better adhesion. The extensive range of bitumen emulsions is covered insufficiently by standardization. DIN EN 13808 for cationic asphalt emulsions has been existing since July 2005. Here, a classification of bitumen emulsions based on letters and numbers is described, considering charges, viscosities, and the type of bitumen. The production process of bitumen emulsions is very complex. Two methods are commonly used, the "Colloid mill" method and the "High Internal Phase Ratio (HIPR)" method. In the "Colloid mill" method, a rotor moves at high speed within a stator by adding bitumen and a water-emulsifier mixture. The resulting shear forces generate bitumen particles between 5 µm and 10 µm coated with emulsifiers. The "High Internal Phase Ratio (HIPR)" method is used for creating smaller bitumen particles, monomodal, narrow particle size distributions, and very high bitumen concentrations. Here, a highly concentrated bitumen emulsion is produced first by moderate stirring and diluted afterward. In contrast to the "Colloid-Mill" method, the aqueous phase is introduced into hot bitumen, enabling very high bitumen concentrations. T The "High Internal Phase Ratio (HIPR)" method is used for creating smaller bitumen particles, monomodal, narrow particle size distributions, and very high bitumen concentrations. Here, a highly concentrated bitumen emulsion is produced first by moderate stirring and diluted afterward. In contrast to the "Colloid-Mill" method, the aqueous phase is introduced into hot bitumen, enabling very high bitumen concentrations (1).he "High Internal Phase Ratio (HIPR)" method is used for creating smaller bitumen particles, monomodal, narrow particle size distributions, and very high bitumen concentrations. Here, a highly concentrated bitumen emulsion is produced first by moderate stirring and diluted afterward. In contrast to the "Colloid-Mill" method, the aqueous phase is introduced into hot bitumen, enabling very high bitumen concentrations (1). Bitumen emulsions are used in a wide variety of applications. They are used in road construction and building protection and primarily include the application in cold recycling mixtures, adhesive coating, and surface treatment (1). Due to the lower viscosity in comparison to hot bitumen, processing requires less energy and is associated with significantly less risk of fire and burns. Chipseal involves spraying the road surface with bitumen emulsion followed by a layer of crushed rock, gravel or crushed slag. Slurry seal is a mixture of bitumen emulsion and fine crushed aggregate that is spread on the surface of a road. Cold-mixed asphalt can