Cutback bitumen
Cutback bitumen is produced by mixing 70/100 or 160/220 Penn grade bitumen with kerosene to adjust the viscosity. This product is determined and designed by the flow time in seconds using a Standard Tar Viscometer (STV). There are three grades of this type of bitumen: 50, 100 and 200 seconds. The main use of cutback bitumen is used for surface dressing, and a large part of it is used to make standard asphalt and cold asphalt (deferred set asphalt). In addition to the STV and solubility tests, the cutback bitumen must match the distillation and penetration properties required for the remaining bitumen. This allows them to make sure that the diluent evaporates at a constant rate during application and service, and they can predict that the amount of remaining bitumen is appropriate and has the proper properties for service.
Soluble bitumen
introduction of soluble bitumen or cutback + applications
Bitumen or asphalt is used to cover the road that we drive every day and even to insulate the roofs. Therefore, bitumen is very important in the industrial applications of road construction and insulation of roofs and buildings. Therefore, the quality of bitumen is very important in making these items. But did you know that bitumen have different types and different uses? One of the types of industrial bitumen is soluble bitumen or cutback bitumen. In this article, we want to explain the definition of cutback bitumen, how it is produced and its uses. But first, let’s see what is soluble bitumen?
What is cutback bitumen or soluble bitumen?
Types of bitumen have different viscosity levels. For some this amount is high and for some this amount is low. Basically, road builders and bitumen applicators heat many bitumen before use and then apply them. But sometimes, they need bitumen that do not require much heating. As a result, they use cutback bitumen, which has a low viscosity. Basically, the main advantage of this bitumen is that most of its products do not need to be heated before application. Therefore, this bitumen is often used in cold regions.
How to produce soluble bitumen
Now that we have explained about cutback bitumen, let’s see how it is produced. If we want to explain the process of making cutback bitumen in simple language, we should say that basically cutback bitumen is bitumen that is mixed with other solvents. These solvents are petroleum products such as crude oil, naphtha, kerosene or diesel. Basically, the role of solvents in soluble cutback bitumen is to thin the bitumen, allowing it to be applied at low temperatures. How to produce soluble bitumen
Preparing materials for making soluble bitumen
First of all, professionals should prepare the materials for making cutback bitumen and determine their ratio. As we explained earlier, solvents are one of the main components of cutback bitumen, and depending on the type of product, their proportion in cutback bitumen can be 10 to 50%. Usually, there are three types of solvents, these types of solvents are fast-acting, slow-acting, and slow-acting solvents. The quick-drying solvent contains gasoline. Fast-acting solvent contains kerosene and slow-acting solvent contains diesel oil. In general, bitumen manufacturers mix cutback solvent with bitumen to reduce bitumen viscosity. Also, depending on the type of use of cutback bitumen and the area in which it is applied, the type of solvent used in cutback bitumen is also different. Even sometimes, manufacturers of soluble bitumen use two types of solvents in its production. (See the article we wrote about natural bitumen.)
The type of bitumen used in making soluble bitumen
To make cutback bitumen, its manufacturers must use a type of bitumen that has a certain degree of penetration. Usually, bitumen used in bitumen solution have a penetration degree of 100/70, 220/160 and 330/250. If the amount of bitumen adhesion is high, the manufacturers of soluble bitumen should heat it a little to combine the bitumen with the solvent.
Mixing bitumen and solvent
After preparing the cutback bitumen ingredients, the manufacturers transfer them to the mixing machine with a pump. Some facilities use a colloidal mill to combine bitumen and solvent. The colloid mill machine can consistently and quickly break down the bitumen droplets and combine them in the solvent. Then, after the process of combining the solvent and bitumen is done, the bitumen manufacturers put the dissolved bitumen in the compressor chamber to cool. Finally, cutback bitumen or dissolved bitumen are transferred or sent for packaging
Types of soluble bitumen
In the previous section, we explained that the types of solvents used in the production of cutback bitumen are different and are of three types: fast-acting, slow-acting, and slow-acting. As a result, their use in mixed or solution bitumen causes the type of cutback bitumen to be different. Therefore, depending on the evaporation rate of the solvent or the drying of the soluble bitumen, the soluble bitumens are divided into three general categories: fast-setting, slow-setting, and slow-setting, which we will explain below.
According to the soluble bitumen standard for adhesiveness, each cutback bitumen classification has its own rating.
Quick-setting bitumen
As it is clear from the name of quick-setting cutback bitumen, quick-setting cutback bitumen dries quickly after being applied to surfaces. The main reason is that the evaporation rate of the solvents used in its production is high. In fact, the evaporation rate of the solvents used in the manufacture of quick-setting cutback bitumen is 0.3 times higher than the evaporation rate of acetone. Therefore, after application, the quick-set cutback bitumen dries quickly on the surface. Also, another name for quick-setting cutback bitumen is soluble RC bitumen and it has different grades.
Soluble bitumen RC30, RC70 and RC250 are fast-setting soluble bitumens, which are mostly used for road maintenance purposes and dry quickly.
MC bitumen
Soluble mc bitumen is a slow-setting soluble bitumen, which is made from solvents that have moderate volatility or volatility. Usually, the rate of evaporation of bitumen solvent of retarder solution varies from 0.3 to 0.8 times the rate of acetone evaporation. Therefore, most manufacturers of slow-setting cutback bitumen use kerosene to produce this bitumen. The important thing about this type of cutback bitumen or soluble bitumen is that this bitumen does not evaporate much when applied to aggregate asphalt mixtures. Therefore, most road builders try to use it as an asphalt binder.
Soluble bitumen MC30, MC70 and MC250 are among the most used types of this cutback bitumen.
Long-lasting soluble bitumen
The evaporation time of slow cutback bitumen is slower than the evaporation time of two quick cutback bitumen. As a result, they use solvents whose evaporation rate is 0.8 times slower than the evaporation rate of acetone to make long-lasting cutback bitumen. Therefore, most solvents such as gasoline or fuel oil are used to make slow-setting bitumen.
Soluble bitumen SC70 and SC250 are widely used cutback bitumen products. Also, the common use of long-lasting cutback bitumen products is in the suppression of soil and cold asphalt.
Advantages of using soluble bitumen
Due to the nature and type of construction of cutback bitumen, this bitumen has its own advantages over other bitumen. For example, the best benefit of using cutback bitumen is its versatility. Since soluble bitumen evaporates quickly, most of its products do not need to be heated before being applied to the road surface or other surfaces. Also, soluble bitumen can be applied at low temperature and above the surface of roads, if for many bitumen it is necessary to heat the bitumen. In addition, when soluble bitumen are applied to the road surface, they break down slowly and are resistant to various weather conditions.
Price of functional bitumen: introduction of functional grade bitumen + applications
Uses of soluble bitumen
Most of the time, most applications of cutback bitumen are for construction, maintenance and road maintenance. Of course, keep in mind that road builders use different methods to apply soluble bitumen, some of which we will explain below.
Applications of cutback bitumen: 1. Cold asphalt
Road builders mostly make cold asphalt at ambient temperature and use a combination of granular materials and liquid bitumen to make it. Therefore, they can use both emulsion bitumen and soluble bitumen to make cold asphalt.
Application of soluble bitumen: 2. Penetration coating
Penetration coating or primer is a layer that is applied on the main layer of the road. Penetration coating manufacturers can use all three types of quick-setting, slow-setting and slow-setting bitumen to make it.
Application of cutback bitumen: 3. Prime coating
If the ambient temperature is too low for the application of cutback bitumen or the movement of cars disrupts the asphalt surface, road builders usually use a soluble bitumen primer to spray on the asphalt. In this way, the cutback bitumen can protect the asphalt for 6 to 12 months.
Application of soluble bitumen: 4. Surface coating
If road engineers want to connect two layers of asphalt together, they use the surface coating method. In this method, the base asphalt layer is usually a combination of penetrating bitumen or viscosity bitumen with aggregates. The surface layer is bitumen, and road construction engineers mostly use emulsion bitumen for surface coating. But they can also use slow setting bitumen for this purpose.
Application of soluble bitumen: 5. Spray sealing
Sometimes the road is damaged but the traffic of cars on it is moderate or low. In these cases, applying a new layer of asphalt is not necessary and, in fact, is an expensive choice. Consequently, a cheaper way to do this is to seal and fill the cracks with the spray method. In this method, repairmen spray a thin layer of cutback bitumen on the surface of the road. Then, this bitumen cutback layer waterproofs the road surface to prevent water from penetrating the asphalt base layer. In the final stage, the repairmen pour stone aggregates on the layer of soluble bitumen.
Application of cutback bitumen: 6. Coating of pipes
As we explained in the previous sections, most of the applications of cutback bitumen are in road construction and repairs. But sometimes, cutback bitumen has other uses in other industries such as pipe making. One of these applications is covering gas and oil pipes. Since gas and oil pipes must be resistant to wear and dust, their manufacturers apply bitumen and fiberglass tape to these pipes. In this method, they first pour a layer of dissolved bitumen on the pipe. Then, they put a layer of fiberglass tape over the bitumen layer.
The price of soluble bitumen
The price of cutback bitumen depends on several different factors. One of the most important factors in determining the price of soluble bitumen in the stock market and the daily price of soluble bitumen is the supply and demand for it. For example, assume a country that is cold and whose road construction industry requires a large amount of cutback bitumen. But if the amount of supply is not equal to the amount of demand for cutback bitumen, the price list of soluble bitumen and emulsion will increase for that country as well.
Cost of components and production process
The price of cutback bitumen components certainly has a great impact on its overall price. As you know, oil prices are constantly fluctuating. Therefore, during periods when the price of oil is high, be sure that the price of soluble bitumen primer will also increase, because oil is one of the main factors in making bitumen. Of course, you should not ignore the costs of the cutback bitumen manufacturing process. These costs are different for each company that makes these bitumens and make the sales of soluble bitumen high and high.
