Types of Bitumen and Bitumen Grade
Everything About Types of Bitumen and Bitumen Grade
Different types of bitumen are available with different properties, specifications, and applications based on consumer industry needs. Bitumen specifications also show differences in safety, solubility, physical properties, and durability. In this article, we will talk about types of bitumen and bitumen grade.
Types of Bitumen
Bitumen can be divided into the following quality classes:
Penetration Grade Bitumen
Oxidized Bitumen Grades
Cut Back Bitumen
Bitumen Emulsion
Polymer Modified Bitumen
Penetration Grade Bitumen
The penetration grade bitumen is a refinery bitumen that is produced in various viscosities. To characterize bitumen, penetration tests are performed based on hardness. Hence it has the name penetration bitumen.
Bitumen penetration grades vary from 15 to 450 for road bitumen. However, the most commonly used range is between 25 and 200. This is determined by controlling the test carried out i.e. the distillation process. Partial control of the flux of residual bitumen by oil helps achieve the required hardness.
BS EN 1426 and BS EN 1427 provide penetration and softening point values for each grade. This helps determine the viscosity and hardness of bitumen grades. Grades are expressed in penetration values. i.e. For instance, 40/60 as a penetration value of 50 ± 10.
BS EN 13303 also provides a measure of heat loss with corresponding limits for all grades of permeable bitumen. This measure is intended to ensure the absence of volatile constituents. Therefore, the component is not processed and its loss contributes to hardening and hardening during the production or laying of bitumen. BS EN 12592 provides solubility values to ensure that bituminous materials are free of impurities.
Oxidized Bitumen | Types of Bitumen
Refinery bitumen is further processed by introducing treated air. This gives oxidized bitumen. Air is injected under pressure into the soft bitumen by maintaining a controlled temperature. The reaction of these introduced oxygens with the bituminous components yields higher molecular weight compounds. Therefore, the content of asphaltenes and maltenes is increased, resulting in a harder compound. This harder compound is less ductile and temperature sensitive.
Oxidized bitumen is used in industrial applications like roofing and pipe coating. This processing method produces a low-permeability bitumen that can be used for road paving.
Cutback Bitumen
It is one of the types of bitumen that corresponds to penetrating bitumen. This type of bitumen is temporarily less viscous due to the introduction of volatile oils.
Once applied, the temporary material evaporates and the bitumen returns to its original viscosity. Osmotic bitumen is a thermoplastic material. It shows different values of viscosity for various temperatures.
In the field of road construction, materials are needed when laying i.e. during surface dressing. It is also important to regain the original hardness and properties of the material after curing. This is ensured by the reduced bitumen. Fluidity is achieved in any bitumen by increasing the temperature. However, cutback bitumen is used when fluidity at low temperatures is required during surface treatment.
Curing time and viscosity of cutback bitumen are varied and controlled by the:
dilution of volatile oil, and
the volatility of the oil added.
70/100 or 160/220 pen bitumen diluted with kerosene is the main component of bitumen used in road construction in the UK. A standard tar viscometer is used to check the standard viscosity.
cutback specifications based on BS 3690 provide the bitumen requirements to meet the dissolution properties, distillation properties, and property recovery after curing.
Bitumen Emulsion | Types of Bitumen
This type of bitumen forms a two-phase system with two immiscible fluids. One is dispersed as fine spheres in the liquid of the other. A bituminous emulsion is formed when individual bituminous beads are dispersed in continuous water. It is a type of infiltration bitumen that is mixed and used for laying purposes.
Emulsifiers with long hydrocarbon chains with either cationic or anionic ends are used to disperse the bituminous beads. This emulsifier provides an electrochemical environment. The ionic portion of the chain has an affinity for water, and bitumen is attracted to the hydrocarbon portion.
Hydrocarbons bind strongly to bituminous beads and ionic moieties can be found on the surface of the beads. Depending on the ions present, the droplets become charged. Emulsions can be cationic (positively charged) or anionic (negatively charged).
Spheres with the same charge repel each other, stabilizing the whole system. Cationic emulsions are preferred to facilitate adhesion with (negatively charged) aggregates.
Emulsion stability depends on the following factors:
Types of bitumen emulsifiers and their quantity
Water evaporation rate
Bitumen quantity
Bitumen globules size
Mechanical forces
Emulsions are applied using a spray. For this reason, viscosity is a major concern. As the bitumen content increases, the mixture becomes more viscous. This becomes sensitive when the volume exceeds 60%. BS 434: Part 1 and BS EN 13808 give viscosity specifications for road emulsions.
Polymer – Modified Bitumen| Types of Bitumen
Polymer-modified bitumen is a type of bitumen obtained by modifying infiltration-graded bitumen’s strength and rheological properties.
The polymers used are either plastic or rubber. These polymers change the strength and viscoelastic properties of bitumen. This is accomplished in the following ways:
Elastic response increase
Improvement in cohesive property
Improvement in Fracture strength
Providing ductility
Some examples of rubber polymers used are styrene block copolymers, synthetic rubbers, and natural and recycled rubbers. Plastics, which are thermoplastic polymers, are also used.
Bitumen Grades
Now it is time to talk about bitumen grades. Four different grades of viscosity grade bitumen including VG10, VG20, VG30, and VG40 are the most widely used bitumen in India which has been exchanged by bitumen penetration grade according to the Indian Standard (IS:73).
This type of bitumen is more dependable than others due to its benefits and properties. Below we detail the bitumen grades so you can find the best VG bitumen you need.
What is the difference between penetration grade bitumen and viscosity grade bitumen?
The dissimilarity between penetration grade bitumen and viscosity grade bitumen is that the penetration grade classification is dependent upon the penetration value at 25°C whereas the VG system is based on the viscosity value at both 60°C and 135°C that demonstrates it is suitable for both low and high temperatures, so the behavior of bitumen under different thermal conditions can be well predicted.
Bitumen Viscosity Grade Classification
Bitumen is classified into several grades including VG10 bitumen, VG20 bitumen, VG30 bitumen, and VG40 bitumen as a result of bitumen viscosity testing. The higher the number, the harder the bitumen is in the viscosity grade system.
Viscosity grade standard
Bitumen viscosity grades are determined by IS 73, ASTM, and AASHTO. According to IS, in 2006 the classification of bitumen will change from penetrating class to viscosity class.
Application of viscosity-grade bitumen
In general, each of these viscosity bitumen grades has different uses, depending on two key factors: climate and traffic conditions.
The important use of VG bitumen is due to the presence of two key properties of this material: waterproofness and high adhesion.
With over 250 different uses for VG bitumen today, it seems impossible to replace it with any other material.
VG 10 Bitumen
VG10 bitumen is the bitumen with the softest viscosity. This type of bitumen is commonly used for spray applications and surface coatings. VG 10 bitumen means that the bitumen is also suitable for paving in very cold climates instead of the old permeability class 80/100. Suitable temperatures for VG10 bitumen range from -10°C to 25°C.
Due to the high temperatures in hot climates, the application of VG10 cannot provide the desired rut resistance. This type of bitumen is also used to make bitumen emulsions and modified bitumen products, especially in India. As a viscosity-grade bitumen, VG10 has excellent cold-weather performance.
What are the advantages of using bitumen with viscosity grade 10?
Suitable for temperatures below 30°C
Absolute viscosity is 800
High penetration value compared to VG30 and VG40
VG 20 Bitumen
VG-20 bitumen is a high-viscosity bitumen used in cold climates and high altitudes. This type of bitumen is suitable for road construction in areas with an average temperature of 30-37 °C.
In North, India vg20 is used for road construction on hot asphalt. The typical penetration value for bitumen with viscosity grade VG-20 is 60 mm at 25 °C. The complete viscosity of VG-20 bitumen is 1600-2400 poise at 60°C.
VG 30 Bitumen | Bitumen Grades
This bitumen is mainly used for the construction of very heavy bituminous pavements that have to withstand considerable traffic loads. Bitumen VG30 is the most widely used type of bitumen in road structure, insulation, the construction industry, and the production of cutback bitumen. It is good to know that this vg30 bitumen can be used in place of 60/70 penetration bitumen.
VG30 Usage in India
VG 30 bitumen is a famous grade of bitumen in India. Indian importers would rather this type of bitumen because of its proven performance in road construction in India. VG 30-grade bitumen is used for plastic roads in India, too.
Since VG30 has good heat sensitivity, it is used in a high-temperature range. VG-30 bitumen is also suitable for use in hot, wet weather as an alternative to bitumen penetrating grades. The more viscous bitumen is, the less susceptible it is to water.
What are the minimum and maximum viscosity of VG-30?
According to the bitumen viscosity classification, VG 30 The 30 in bitumen means the viscosity range [(100 +- 20) * 30] in poise. You can calculate the minimum and maximum values of VG30. The minimum viscosity at 60°C can be calculated as:
80 * 30 = 2400 poise, but the maximum viscosity is also calculated by this formula
120 * 30 = 3600 poise.
Difference between VG10 and VG30
The difference between VG10 bitumen and VG 30 bitumen is viscosity. Bitumen VG30 is more viscous than bitumen VG 10 and is therefore more suitable for road construction in hot regions.
What are the advantages of using Grade 30 bitumen?
Suitable for temperatures above 30°C
Bitumen with high viscosity is suitable for clayed soils
VG30 is suitable for road construction in rainy weather
VG 40 Bitumen | Bitumen Grades
What does VG40 mean?
VG40 bitumen is used in areas where high pressure is generated by heavy traffic loads such as Near junctions, toll booths, and truck parking lots. The high viscosity of this bitumen makes it suitable for improving resistance to slippage and other problems associated with high temperatures and heavy traffic. It’s been a long time since the industry used vgVG-40 to replace 40/50 infiltration bitumen.
Difference between VG30 and VG40
The difference between vg30 and vg40 is that VG 30 bitumen is suitable for warm climates and VG 40 bitumen is suitable for use in hot climates.
What are the advantages of using bitumen with viscosity grade 40?
Suitable for temperatures above 40°C
Absolute viscosity is 3200
This is the preferred type of bitumen where heavy traffic is expected.
How do I choose the right viscosity grade bitumen?
To select a suitable viscosity bitumen based on the IS73 standard, the average site temperature should fall within one of the ranges in the table below.
Grade Suitable for 7 days Average Maximum Air Temperature ° C
VG 10 < 30
VG 20 30 – 38
VG 30 38 – 45
VG 40 > 45
The average temperature equals the average temperature of the hottest week of the year for at least five years. Although there are some hotter-than-normal days, it is essential to consider average temperature as an indicator for this classification.
Conclusion
In this article, we discussed bout types of bitumen, bitumen grades, and other important things that you must know about them. We hope you could find the answers to your question here. But if there are further questions, please feel free to ask our specialists in Bitumen co.
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