Bitumen Emulsion Production
How is bitumen emulsion prepared?
Bitumen emulsions are bitumen dispersed in water in small pieces. The width of the particles is normally between 1 and 5 microns. Bitumen emulsions find wide applications in roadworks, construction, and their repairs in many places.
No use of the distilled petroleum products like kerosene, diesel oil, naphtha, etc., is made in the use of emulsions. Energy use is less because of the lower heat requirement for the manufacturing process compared to hot mixes. It also reduces the environmental pollution considerably by not using these distilled petroleum products.
A desirable emulsion is slippery and brown in color. In the bitumen emulsion, the bitumen disperses in the water and forms an emulsion with the properties of water.
Bitumen forms the P-70 part of the emulsion. Emulsions are generally produced with bitumen with a penetration value of 100 to 250. However, bitumen hardness may change due to climatic conditions.
Bitumen emulsion properties vary depending on the chemicals used as emulsifiers. These materials determine whether the emulsion is anionic, cationic, or nonionic. In addition, the emulsifiers prevent the settling of bitumen particles and ensure that the bitumen adheres to the aggregate surface at the right time and form.
Water gives consistency to the bitumen emulsion. The water to be used must be suitable for the production of the emulsion.
What are the Bitumen Emulsion Types?
In the area where it is applied, by evaporation of the water, a black layer is formed waterproof and the adhesion strength increases. In anionic emulsions, the particles are spherical and small. These emulsions are safe against fire and pollute the environment less. But these emulsions can't be used with all kinds of aggregates, and they are sensitive to the precipitation.
It is a bituminous binder, primer, and adhesive material applied to road pavements. Cationic emulsions are less sensitive to precipitation. Besides, more bitumen can be dispersed in the water without changing the quality of the emulsion.
What are the Usage Areas of Bitumen Emulsions?
Micro Coatings is a polymer-added cold mix superstructure material used to improve the deterioration of road and airport coatings.
Slurry seal
Slurry seal is applied to roads as a surface treatment in order for the road to last longer, wearing out less. It is a mixture of fine aggregates, asphalt emulsion, water, and additives laid down over the old road surface. Slurry seal is generally intended to seal minor cracks, preventing intrusion by water, providing better skid resistance on the road. Application of the slurry seal rejuvenates the aging asphalt surface by providing a new wear surface for extending pavement life. Spreading the slurry mixture evenly over the road surface requires special equipment; after application, a curing time should be allowed for it to solidify and bond to the existing pavement. Slurry seals are among the cost-effective treatments for maintenance because they can be laid in extremely short periods. It, therefore calls for a far shorter length of time of closing the road compared to other methods used to carry out resurfacing of pavements. Generally, applications involving slurry seal are vital parts of any road maintenance program since they guard against pavement deterioration while providing motorists with a safe and smooth driving surface.
Chip seal surface repair
One widely used method of road maintenance to prolong the life span of existing asphalt roads is chip seal surface repair, simply chip seal, or surface dressing. The asphalt emulsion is sprayed onto the road surface, after which an even layer of aggregate chips is spread over the same area. The aggregate chips compact into the emulsion to form a strong and skid-resistant surface. The benefits of chip seal surface repair include the fact that it seals small cracks, waterproofs pavement, restores friction to the surface, and simply makes the road look better in general. Chip sealing is a pretty inexpensive process that can be performed in the effort to maintain roads and protect them from the deteriorating effects of the traffic and weather. Generally, chip seal treatments are applied to rural roads, low-traffic highways, and residential streets for surface quality improvement and prolongation of pavement life. Chip seal surface repair may reduce road roughness for some time and give a new driving surface, but maintenance or re-application might be necessary to ensure long-lasting performance or optimal conditions of the road.
Fog seal
Fog seal is a surface treatment methodology in asphalt pavement used in maintaining asphalt pavements to rejuvenate and protect existing in-service road surfaces. The application of a thin layer of asphalt emulsion, more commonly referred to as a fog coat, directly to the pavement surface. Specialized equipment-a distributor truck-applies the emulsion uniformly across the road, laying down a very thin film in the process of sealing the underlying asphalt surface. Applications for fog seals include rejuvenating flexibility in aged pavements, sealing minor cracks, and protecting the roadway from water infiltration and oxidation caused by sunlight exposure. Surface friction can be improved, and the general appearance of the pavement enhanced, which can contribute to an extended lifespan of the roadway. This is a relatively inexpensive maintenance treatment, which is very effective in preserving low traffic roads, residential streets, and parking lots. While fog seals may provide an immediate benefit, the integrity and performance of the asphalt pavement may necessitate frequent monitoring and reapplication of the treatment over time. A comprehensive fog seal in a pavement maintenance program prolongs the life of the infrastructure and provides safe driving conditions to road users.
Recycling
The reuse of asphalt pavements. The advantages of recycling asphalt pavements are many. These;
It is less expensive.
The road can be stabilized .
The problem of rubbish is removed.
In this way, the available resources are not wasted .
Cold Mix Bitumen Emulsions
Bitumen emulsions and aggregates have been used together in many countries for several decades. These mixtures were not, however considered to be a pavement material for the highways carrying heavy traffic loads prior to the early 1980s. In these years, the reactions put forward to prevent the fast depletion of energy resources and to decrease the environmental pollution especially in USA has expanded the usage of cold mix materials as a carrier layer in the road superstructure in some countries including Turkey.
In cold mixes, the bitumen and aggregate need not be heated. Because of this reason, the aggregate dryers and heating systems are not needed. Moreover, the thinner petroleum fluids are not needed for reducing the consistency of the asphalt emulsion.
All these factors lead to a great deal of energy savings, hence making their use far more economical.
Advantages of Bitumen Emulsions
It is more economical than hot mixtures.
Environmental pollution problems do not arise due to gas emissions during the production of hot mixtures.
Bitumen emulsion mixes are "cold mix". As such, heating of the bitumen and the aggregate does not need; hence, the aggregate dryers and heating systems.
Requirements for thinner petroleum fluids do not arise either. These factors result in energy economy and such materials become more economical.
Since they are water-based, they do not pollute the environment. In the cold mixture, since the temperature is at room temperature, the harmful gases emitted by the hot mixtures are in liquid form. For this reason, significant gas diffusion does not occur.
Disadvantages of Bitumen Emulsions
Although bitumen emulsion applications have a long history in pavement works, their use is still not as widespread as hot mixes, mainly because of the weak early age strength and slow development of strength. Because of some disadvantages, it is not possible to apply them in every case.