Bitumen emulsions are basically an O/W – Oil on Water
solution – A dispersion of bitumen particles on water phase, stabilized with
the addition of surfactants – Surface active agents – or most commonly known as
emulsifiers. They are primarily used for tack coats for use in between hot mix
asphalt layers and prime coats for thin hot mix surfacing layers or a chip seal
pavements, other cold mixed asphalt and maintenance binder . Bituminous
emulsions or slurries are two-phase systems that are composed of bitumen, water
and one or more additives to form, stabilize and improve the properties of
slurries.
Bitumen emulsions are divided into three categories:
* Anionic with negatively charged globules
* Cationic with positively charged globules
* Non-ionic with neutral globules.
Emulsion bitumens are classified into the following types
according to the breaking speed and type of application:
RS quick breaking emulsion bitumen
Bitumen slow breaking MS
Emulsion bitumen SS
Currently, the type of cationic precipitator is the most
widely used in the country.
Base on the time of setting after spraying, Bitumen emulsions classification as
Quick Set (QS), Rapild set (RS), Medium set (MS) and Slow set(SS)