Bitumen emulsion is a solution of bitumen in water, which is stable by emulsification and is prevented from settling bitumen in water. The first emulsion of bitumen was recorded in 1922 by Hugh Ellen Mackie. At that time, automobile industries had boomed a lot, and a lot of roads were being built. Now that it has been over 80 years old, this technology is still the best technology for
Road construction is considered.
Emulsion bitumen
Introduction:
Each emulsion consists of a system with two non-interconnecting phases. One of the two phases is RBC or small pellets dispersed in the other phase. A fuselage that is a small bullet is called the internal phase, and the phase that surrounds these bullets is known as the outer phase or continuous phase. In each emulsion, it can be determined in various ways that the continuous phase and which phase is non-continuous . For example, in the "oil-in-water" emulsion, the non-continuous phase oil and continuous water phase are formed. Bituminous emulsions are generally oil-in-water emulsions, the non-continuous phase being small pellets of bitumen that are dispersed in water.
history:
The first emulsion bitumen was recorded in 1922 by Hugh Ellen Mackey. At that time, automobile industries were making a lot of progress and a lot of roads were being built. The production of emulsion bitumen in France, known as the cradle of this technology, increased from 10,000 tons in 1923 to 300,000 tons during World War II, reaching 1,200,000 tons in 1970. Today, 30% of all French roads are made of emulsion and are being built in all parts of the world. Most of the bitumen used in road construction have a dense and semi-solid state in normal heat. For this reason, in the coating asphalt operation, it should first be flooded with the help of heat and then spread a thin layer of them on the surface.
Since the provision of facilities and heating systems for bitumen in remote locations is neither feasible nor cost-effective, asphalt experts have tried in some way to apply cold bitumen in road construction. With the appearance of bitumen emulsion, not only the use of bitumen in cold weather was practically possible, but also the defect in the application of mixed bitumen is not considered in this case. Because the bitumen of the emulsion is very fluid and, if the water gets wet, the surface of the road or materials used will create a good adhesion between the bitumen and the materials.
Water and bitumen are not mixed with each other, but emulsion technology has made this process so that a large percentage of bitumen is dispersed in the continuous phase of water. A compound called the emulsifier, holds particles of bitumen in a suspended state for a continuous phase in the continuous phase (electric charge). In this mixture, bitumen floats in water, but it also floats in very small amounts of blood cells. In some cases, the emulsifier may also be used as a stabilizing agent. Bituminous emulsions are mainly oil-based emulsions in water, bitumen is dispersed in the water phase. In these bitumen emulsions, the amount of bitumen depends on its application, which usually varies from at least 55% to a maximum of 65%.
The benefits of bitumen emulsions to soluble bitumen include:
1. No need for heating during use
2. No need for petroleum solvents
3. Non-fire during storage, transportation and execution
4. Non-pollution of the environment
5-Ability to use in wet conditions
6. Widespread applications in road construction
The precipitated emulsions are classified into three types of cationic, anionic, and non-ionic, in terms of breaking speed into three types of fasting (RS), slowdown (MS), delayed (SS), and electrically charged particles of suspended particles. Since the emulsifiers are active chemicals, they determine the electrical charge of the emulsion. In the preparation of precious emulsion, a small amount of this chemical is added to facilitate the formation of bituminous cells and stable suspension.
Most of the blenders used in the surface asphalt used in emulsion are cationic, which means that bituminous particles in these emulsions have a positive charge.
Positive ions that surround the bitumen particles in the emulsion are in contact with rocky materials and stick together bitumen to the aggregate, starting to absorb the bitumen to start the emulsion failure. With the onset of failure, the bitumen particles are aggregate and stick together and grow larger and larger. This process occurs faster by material congestion or the use of accelerating agents.