Water-bitumen emulsion is a highly dispersed dark brown material made by atomization of bitumen in water solution of an emulsifier.
Such methods of bitumen thinning as organic solutions and hot mastics are prohibited in several European countries due to environmental and health hazards. A better and more efficient method is emulsification. The process is becoming more popular, replacing the other methods and taking its well deserved place in the market.
Although emulsion itself is an advanced material for road construction and waterproofing of buildings, it is often modified with synthetic polymer additives to enhance its performance even further. Such materials are called polymer-bitumen emulsions or rubber-bitumen emulsions.
Injection of polymer into bitumen emulsions is becoming more and more popular, since polymer-bitumen emulsions are obviously better for construction and repair of roads. Bitumen modification allows production of high quality emulsion, compliant with the high demands and high loads of modern roads. Modified water-bitumen emulsions improve stability and durability of road top and extend the temperature range of operation, elasticity and deformation stability. Research shows that bitumen, extracted after ten years of operation, shows little change of viscosity. The use of polymer-bitumen emulsion reduces the time of layer formation, however, additional adhesive additives are recommended to improve performance.
Water-bitumen emulsion can be modified in one of the three methods.
First method: injection of modifier into bitumen before emulsification.
Second method: injection of polymers into colloid mill at the stage of emulsion preparation.
Third method: mixing of two emulsions, where prepared emulsion is mixed with modifiers in the form of another emulsion.
Polymer bitumen emulsions are designed not only for road construction, but are also widely used for water-proofing of above and below ground structures, roofs etc. Water proofing materials made of water-bitumen emulsions protects structures from adverse effects of water.