Bitumen Emulsion: What is it?
There are three categories of Bitumen Emulsion, with the first two being by far the most significant in terms of volume:
Cationic emulsions
- Emulsion anionic;
- Emulsions without anion;
The total particle charge that the emulsifier imparts to the bitumen droplet is referred to as the cationic, anionic, or nonionic Bitumen Emulsion. An anionic emulsion is one in which the bitumen particles are negatively charged, causing the droplets to migrate to the anode if an electric charge is applied to it. In contrast, positively charged particles will migrate to the cathode, and this results in cationic emulsions, which are positively charged particles. Nonionic emulsions include neutral bitumen droplets, which prevent migration to either pole. Clay emulsions are one type of such nonionic emulsion.
The following variables affect how stable emulsions are:
- Bitumen Emulsion types and amounts; •
Water evaporation rate
- Bitumen production
- Bitumen globules’ dimensions:
- Mechanical pressures
Applying the emulsions requires the use of sprays. Viscosity is the main issue here. The mixture becomes more viscous as the Bitumen Emulsion concentration rises. When the percentage is greater than 60%, this is discovered to be sensitive.
ACCORDING TO SETTING TIME
WATER BEGINS TO EVAPORATE WHEN Bitumen Emulsion ARE APPLIED TO AGGREGATES, CAUSING THE SEPARATION OF BITUMEN FROM WATER. Then bitumen spreads across the aggregate’s surface, acting as a binding material and gradually gaining strength.
It is divided into the following three types based on how quickly water evaporates and bitumen particles separate from water.
- QUICK SET EMULSION (RS)
- EMULSION ON A MEDIUM SETTING (MS)
- EMULSION WITH A SLOW SETTING (SS)
BITUMEN EMULSION CHEMISTRY
Describe the emulsifying agents in further detail.
Fatty acids and lignin from wood are the most often used products; they combine with sodium hydroxide to produce soap. In water, soaps take on a negative charge and produce “Anionic” Bitumen Emulsion. Amines are a different category of emulsifiers that are made from wood acids (tall oils) or animal fats (tallows). These emulsifiers produce soaps, which in water take on a positive charge and produce cationic asphalt emulsions.
Bitumen Emulsion: how are they created?
A high-speed mixer known as a colloid mill is used to combine hot asphalt with water and soap (emulsifier). The asphalt is broken up into tiny droplets by the soap and strong shear, which stay scattered in the water.
How do they function?
In order to “glue” the aggregates together, asphalt emulsion must be combined with the aggregates used in road building. This causes the Bitumen Emulsion to destabilize and cause the asphalt droplets to fuse together. While water evaporates, emulsifiers are left in the asphalt, where they serve a crucial purpose in making the asphalt adhere to the aggregate.
Emulsifiers’ Mechanism of Action
Surfactants (soaps), which include both cationic and anionic emulsifiers, provide the emulsion with stability.
Prevents the asphalt from separating from the water and provides a charge
Positive vs. negative (cationic vs. anionic; setting attributes)
Three settings: slow, medium, and quick
Use of Bitumen Emulsion Benefits
When in use, the heating process is not necessary.
There is no requirement for chemical solvents.
There is no danger of fire when being stored, transported, or used.
Environmental pollution is not a concern.
Applications of Bitumen Emulsion result in either no or very little hydrocarbon emissions.
Petroleum solvents are not required for emulsification. (Small quantities of solvent may be added to some mixing grade emulsions to improve mixing capabilities.
Emulsions may be used in the majority of applications at room temperature without additional heat and with little to no odors.
Suitable for humid environments.
Extensive use in the building and maintenance of roads.
The stability of shifting sands and mulching are two other uses for bitumen emulsion that are beneficial for the desert and western regions of the nation that is in danger of dust exposure.
Emulsions are perfect for non-attainment regions with restricted fume emissions.
Emulsions are perfect for rural areas without hot mix plants.
Manufacturers of Cationic Bitumen Emulsion are easy to apply to moist aggregate surfaces, which lowers the amount of fuel needed to dry aggregates.
Applications for pavement preservation considerably minimize the amount of energy and raw materials needed for rebuilding and corrective maintenance.
Why Pavements that are well maintained and smoother use less maintenance and gasoline.
A group of highly qualified individuals from the industry who are committed to creating high-quality bitumen emulsion manage the manufacture and processing.