Bitumen emulsion and its components

GlobeCore develops and manufactures state-of-the-art colloid mills and dispersers for preparation of bitumen emulsions.

Water-bitumen emulsion is a liquid highly dispersed dark brown material, prepared by fragmentation of bitumen in a water solution of emulsifier. In comparison with bitumen solutions and hot mastics, emulsion has several advantages:

• environmental safety (decreased amount of organic emissions);
• better product (elasticity and durability);
• better economic performance (source material and energy savings);
• safety (emulsions are inflammable and less carcinogenic).

The main area of application of bitumen emulsions is road construction. Bitumen emulsions are becoming more widely used for road construction and repairs than other methods of bitumen thinning. Beside modern road applications, bitumen emulsions are widely used for water-proofing and roofing, ensuring better production of structures from water and its destructive effects.

There are oil-in-water and water-in-oil emulsions. As a rule, oil-in-water emulsion, where bitumen particles are uniformly dispersed in water, rather than the reverse, are more widely used.

Dispersed bitumen and water may form emulsions, but such mixes quickly separate back into the initial phases. Emulsion stability is ensured by emulsifier, a surfactant which may vary depending on particle charge. Water bitumen emulsions can be of two types: anionic emsulsion and cationic emulsions. Anionic emulsions are prepared with such surfactants as higher organic acids or salts, while cationic emulsions are prepared with amines, diamines, polyamine and quarternary ammonium salts. Versatility and good adhesion of cationic systems are significant advantages in road construction.

Various polymer additives are introduced into bitumen emulsions to improve their physical properties. The resulting materials are referred to as polymer-bitumen or resin-bitumen emulsions.

Improved stability, viscosity and adhesion additives are facilitated by stabilizes components (calcium chloride), acids (chlorine and phorphorus acids), solvents (oil fractions) and thinners (vacuum gas oils and oil fractions). Water-bitumen emulsion qualities and characteristics of its components are regulated by national and international standards.