VG Bitumen
WHAT IS VISCOSITY GRADE BITUMEN (VG BITUMEN)
Viscosity Grade Bitumen: Viscosity in the context of bitumen refers to the thickness or resistance to flow of bituminous materials, such as asphalt or tar. Bitumen is a highly viscous and sticky black or brown substance that is derived from crude oil during the refining process. Its viscosity is a key property that determines its suitability for various applications, especially in the construction and paving industries. Bitumen viscosity is influenced by several factors, including temperature, shear rate, and the type of bitumen.
HERE ARE SOME KEY POINTS TO UNDERSTAND ABOUT BITUMEN VISCOSITY:
Temperature Dependence: Bitumen’s viscosity is highly temperature-dependent. As temperature increases, bitumen becomes less viscous and flows more easily. Conversely, as temperature decreases, bitumen becomes more viscous and can become solid or very thick.
Rheology: Bitumen’s flow behavior, or rheology, is described as non-Newtonian, meaning its viscosity changes with shear rate. At low shear rates, such as when it’s not being actively mixed or agitated, bitumen can be very thick and exhibit high viscosity. When subjected to high shear rates, as in the mixing and application processes, it becomes less viscous and easier to work with.
Grading: Bitumen is often classified into different grades based on its viscosity at specific temperatures. The most commonly used grading system for bitumen is the penetration grading system and the viscosity grading system. For example, the penetration grade 60/70 bitumen has specific viscosity and penetration values at certain temperatures.
Application: The choice of bitumen viscosity is crucial in various construction and paving applications. Lower viscosity bitumen is used in applications where it needs to flow easily, such as in asphalt paving, while higher viscosity bitumen is used in roofing materials and waterproofing applications.
Modifiers: Bitumen can be modified with additives and polymers to alter its viscosity and other properties. This is done to improve its performance in specific applications, such as increasing its resistance to cracking or improving its adhesion properties.
In summary, viscosity in bitumen refers to its thickness and resistance to flow, which are crucial factors in determining its suitability for different applications. Bitumen’s viscosity can vary with temperature, shear rate, and grade, and it can be modified to meet specific performance requirements in various industries.
GENERAL INFORMATION OF VISCOSITY GRADE BITUMEN (ASPHALT)
Viscosity Grade Bitumen (Asphalt) is a standard grade Bitumen usually used as a Paving Grade Bitumen suitable for road construction and for the production of asphalt pavements with superior properties. This grade of Bitumen is mainly used in the manufacture of hot mix asphalt for bases and wearing courses and possesses characteristics and qualities unique sand quite different from other agents. They achieve very flexible and tenacious connections with other materials due mainly to the viscoelastic response of bitumen, which behavior depends on how fast charges are applied. Viscosity Grade Bitumen supplied by RAHA OIL is petroleum grade bitumen, manufactured from a fractional / vacuum distillation of crude oil, which practical appliance and behaviour varies according to its temperature. The Bitumen supplied by Raha Oil is produced from vacuum residue (short residue) feedstock. Viscosity Grade bitumens are specified by the methods described in ASTM Standard D3381-09 and AASHTO M226-80 (2008). Viscosity Graded specifications covers bitumen (asphalt) graded by Viscosity at 60 C (140 °F).
VISCOSITY GRADE BITUMEN (VG BITUMEN) HISTORY
Viscosity Grade Bitumen, often abbreviated as VG bitumen, is a type of bitumen that is classified and characterized based on its viscosity at a specific temperature. It is widely used in the construction and paving industry, and its history can be traced back to the development of standardized specifications for bitumen to ensure consistency and quality in various applications.
HERE IS SOME INFORMATION ABOUT THE HISTORY OF VISCOSITY GRADE BITUMEN:
1-Early Bitumen Use: Bitumen has been used by civilizations for thousands of years, primarily as a waterproofing and adhesive material. Ancient civilizations like the Sumerians and Egyptians used bitumen for various applications, including building construction and shipbuilding.
2-Emergence of Modern Bitumen Standards: As industrialization advanced, the need for standardized specifications for bitumen became evident, especially in the construction and road paving industries. Standardization was essential to ensure that bitumen met specific performance criteria.
3-Penetration Grading System: One of the earliest systems for classifying bitumen was the penetration grading system. In this system, bitumen was classified based on its penetration depth (the distance a standard needle penetrates the bitumen sample) at a specific temperature. However, this system had limitations in accurately characterizing bitumen’s behavior at higher temperatures.
4-Development of Viscosity Grading: To address the limitations of the penetration grading system, the viscosity grading system was developed. Instead of measuring penetration depth, this system measures bitumen’s viscosity at a particular temperature, typically 60°C (140°F) and 135°C (275°F). Viscosity grading provides a more accurate representation of bitumen’s flow behavior, especially at higher temperatures, which is crucial for asphalt paving.
5-Standardization: The development and standardization of viscosity grade bitumen specifications were primarily carried out by organizations and agencies responsible for road and construction standards in various countries. For example, in the United States, the American Society for Testing and Materials (ASTM) developed standards for viscosity grade bitumen.
6-Global Adoption: Viscosity grade bitumen specifications have been adopted worldwide to ensure that bitumen used in road construction and other applications meets specific performance requirements. Different countries and regions may have their own variations of viscosity grading systems, but the principles are generally consistent.
7-Continued Advancements: Over time, research and advancements in bitumen technology have led to the development of modified bitumen products that offer improved performance characteristics, such as increased resistance to cracking and improved durability.
In summary, the history of Viscosity Grade Bitumen (VG Bitumen) is closely linked to the need for standardized specifications in the construction and road paving industries. The development of viscosity grading systems represented a significant step forward in accurately characterizing bitumen’s behavior at different temperatures, ensuring the quality and consistency of bitumen products used in various applications.
ADVANTAGES AND DISADVANTAGES OF VISCOSITY GRADE OF BITUMEN
HERE IS SOME ADVANTAGES TO REVIEW:
1–Unlike penetration depth, viscosity is a fundamental engineering parameter.
2-Test temperatures correlate well with:
- 25°C (77°F) – average pavement temp.
- 60°C (140°F) – high pavement temp.
- 135°C (275°F) – HMA mixing temp.
3-Temperature susceptibility (the change in asphalt binder rheology with temperature) can be somewhat determined because viscosity is measured at three different temperatures (penetration only is measured at 25°C (77°F))
4-Testing equipment and standards are widely available.
HERE IS SOME DISADVANTAGES TO REVIEW:
1-The principal grading (done at 25°C (77°F)) may not accurately reflect low-temperature asphalt binder rheology.
2-When using the AC grading system, thin film oven test residue viscosities can vary greatly with the same AC grade. Therefore, although asphalt binders are of the same AC grade they may behave differently after construction.
3-The testing is more expensive and takes longer than the penetration test.
VISCOSITY GRADE BITUMEN (VG BITUMEN) PRODUCTION PROCESS
The production of Viscosity Grade Bitumen (VG Bitumen) involves several stages, from the extraction of crude oil to refining and grading based on viscosity.
HERE IS A GENERAL OVERVIEW OF THE PROCESS:
Crude Oil Extraction: The first step involves extracting crude oil from oil wells. This crude oil consists of various types of hydrocarbons, including the heavy fractions that form bitumen.
Distillation: The extracted crude oil undergoes atmospheric distillation in a refinery. This process heats the oil, causing different fractions to evaporate and condense at different temperatures. The lighter fractions, such as gasoline and diesel, are removed at lower temperatures, while the heavy bitumen fraction is left behind.
Vacuum Distillation: The remaining heavy oil from the atmospheric distillation unit is then subjected to a second distillation process under vacuum conditions. This step enables the removal of the remaining lighter fractions without causing thermal cracking of the bitumen.
Air Blowing: To achieve desired properties, the vacuum residue is then subjected to an air-blowing process, where hot air is passed through the residue. This procedure induces certain reactions that enhance the bitumen’s physical and performance properties, allowing it to withstand various weather and load conditions.
Viscosity Grading: The final stage of the process is the grading of the bitumen based on its viscosity. The bitumen is heated to a standard temperature of 60°C, and its viscosity is measured in centistokes (cSt). Depending on the viscosity, the bitumen is categorized into different grades, such as VG10, VG20, VG30, or VG40.
Keep in mind that the specifics of this process can vary depending on the quality of the crude oil and the desired properties of the final bitumen product
VISCOSITY BITUMEN (VG BITUMEN) HS CODE, CHEMICAL FORMULA AND CAS NUMBER
Viscosity Grade Bitumen (VG Bitumen) is an essential material for road construction and roofing applications. It is classified under several codes and identifiers, which are used for its transportation and trade.
HS Code: The Harmonized System (HS) Code for bitumen, including VG Bitumen, is 27132000.
This HS code refers to “Bituminous or oil shale and tar sands.”
Chemical Formula: Bitumen doesn’t have a precise chemical formula as it is a complex mixture of hydrocarbons. The composition of bitumen can vary widely, containing thousands of different molecules, mainly composed of carbon and hydrogen, and often also containing oxygen, sulfur, and nitrogen.
CAS Number: Similar to the chemical formula, there isn’t a specific Chemical Abstracts Service (CAS) number for VG Bitumen as it is a mixture of various compounds. However, the CAS number generally used for bitumen is 8052-42-4, though it’s crucial to remember that this covers a broad range of materials, including the different viscosity grades of bitumen. Remember, these codes and identifiers help in the proper classification and documentation of VG Bitumen, particularly in international trade and safety data sheets.
VISCOSITY GRADE BITUMEN (VG BITUMEN) APPLICATIONS AND USES
Viscosity Bitumen is a grade of bitumen that is most often used as a paving grade. It is appropriate for the building of roads and is effective in providing prime qualities in asphalt pavements. Raha Oil provides a wide range of high-quality grades in this category, which has been listed below.
BITUMEN VG-10
Spraying VG10 bitumen, which has a permeability rating of 80/100, is the method of choice for coating surfaces and roads. This particular variety of bitumen is required for the manufacturing of emulsions bitumen and other modified bitumen products. This grade of bitumen can be a good substitute for penetrating bitumen 80/100.
ADVANTAGES OF VISCOSITY GRADE BITUMEN 10
- It is appropriate for temperatures below 30 °C.
- It has an 800 absolute viscosity.
- When compared to VG30 and VG40, it has a better penetration value.
BITUMEN VG-20
Paving applications in areas with low temperatures and high elevations.
ADVANTAGES OF VISCOSITY GRADE BITUMEN 20
High-altitude, cold climate areas employ VG-20 bitumen, a grade of viscosity bitumen. When building roads in areas where the average temperature is between 30 and 37 °C, this grade of bitumen is appropriate.
BITUMEN VG-30
VG30 grade viscosity bitumen is used to build super heavy bituminous pavements. These types of sidewalks must withstand high and significant traffic loads, so this type of grade is used more often. Road construction, construction, insulation, and liquid bitumen are the most common industries that use this type of bitumen. VG30 bitumen is very suitable for temperate climates and can be used instead of bitumen 60/70.
ADVANTAGES OF VISCOSITY GRADE BITUMEN 30
- It can withstand temperatures higher than 30 °C.
- Bitumen with a greater viscosity is more suited for a clayed soil.
- In wet conditions, VG30 is better appropriate for road building.
BITUMEN VG-40
In highly stressed areas such as intersections, highways near tolls, and truck parking lots, VG 40 bitumen with a permeability of 40/50 is used instead of the old bitumen. Due to its high viscosity, this type of mixed hard bitumen is suitable for surfaces that are supposed to bear high tensile strength loads and heavy traffic loads. This type of bitumen is used at higher temperatures and on surfaces that require more resistance and it can be a suitable alternative to penetration bitumen 40/50 and penetration bitumen 30/40.
ADVANTAGES OF VISCOSITY GRADE BITUMEN 40
- It can withstand temperatures exceeding 40 °C.
- It has a 3200 absolute viscosity.
- It is the ideal kind of bitumen when there will be a lot of traffic.
THE DIFFERENCE BETWEEN VG10 AND VG30
The difference between VG10 and VG-30 bitumen is in their viscosity level. Bitumen VG30 is more viscose than bitumen VG 10 and as a result, performs better in road construction in hot regions.
DIFFERENCE BETWEEN PENETRATION GRADE BITUMEN AND VISCOSITY GRADE BITUMEN
The difference between penetration grade bitumen and viscosity grade bitumen is that the penetration grade classification is based on the Penetration value in 25 ◦C, while VG system is based on Viscosity value in both 60 ◦C and 135 ◦C that shows it is suitable for both low and high temperature so the bitumen behavior in different thermal conditions can be predicted well.
CLASSIFICATION OF VISCOSITY GRADE BITUMEN
Viscosity test on bitumen results the classification of bitumen in a range of grades, including VG10 Bitumen, VG20 Bitumen, VG30 Bitumen, and VG40 Bitumen. The higher the number, the harder the bitumen in the viscosity grading system. To know more about VG’s specification and comparison of the properties of grades, see the table at the end of the article.
VISCOSITY GARDE STANDARDS
Viscosity Grade bitumen is determined by IS 73, ASTM and AASHTO. According to the IS, grading of Bitumen is changed from penetration grade to viscosity grade in 2006.
THERE ARE TWO METHODS OF GRADING:
1- Standard Viscosity Grade Bitumen (AC-Grades), in which the Viscosity of the standard bitumen (asphalt) is measured at 60 ºC (140 ºF).
2- RTFOT Viscosity Grade Bitumen (AR-Grades), in which the Viscosity of bitumen (asphalt) is measured at 60 °C (140 °F) after the roll on thin film oven test.
Viscosity grade bitumens have a thermoplastic property which causes the material to soften at high temperatures and to harden at lower temperatures. This unique temperature/ viscosity relationship is important when determining the performance parameters such as the adhesion, rheology, durability and application temperatures of bitumen. In the Viscosity Graded Bitumen specifications further, special emphasis is placed on the Bitumen ductility.
STANDARD VISCOSITY GRADE BITUMEN BLINDERS INCLUDE:
- Viscosity Grade Bitumen AC-2.5
- Viscosity Grade Bitumen AC-5
- Viscosity Grade Bitumen AC-10
- Viscosity Grade Bitumen AC-20
- Viscosity Grade Bitumen AC-30
- Viscosity Grade Bitumen AC-40
RTFOT VISCOSITY GRADE BITUMEN BLINDERS INCLUDE:
- Viscosity Grade Bitumen AR-1000
- Viscosity Grade Bitumen AR-2000
- Viscosity Grade Bitumen AR-4000
- Viscosity Grade Bitumen AR-8000
- Viscosity Grade Bitumen AR-16000
VISCOSITY GRADE BITUMEN (VG BITUMEN) PACKING
There are different type of packing such as: New Steel Drum, Jumbo Bag, and Bulk.
VISCOSITY GRADE BITUMEN (VG BITUMEN) TRANSPORTATION AND STORAGE
Transporting and storing Viscosity Grade Bitumen (VG Bitumen) can be done using different packaging options. Below, we will discuss three common packaging types for the transportation and storage of VG Bitumen: New Steel Drum, Jumbo Bag, and Bulk.
New Steel Drum: This packaging type involves using new and intact steel drums for the transportation and storage of VG Bitumen.
The drums have secure lids to preserve the quality and weight of VG Bitumen during transportation.
Steel drums are typically suitable for smaller volumes of VG Bitumen and are suitable for use in smaller or limited spaces.
Jumbo Bag: Jumbo bags, also known as big bags, are another packaging option used for the transportation and storage of VG Bitumen.
These bags are made from durable and high-strength materials, capable of carrying heavy loads.
Packaging with jumbo bags is particularly suitable when there is easy access to loading and unloading equipment.
Bulk: Bulk packaging refers to transporting VG Bitumen in a non-packaged, direct form in large cargo vehicles.
This method of transportation is usually used for larger volumes of VG Bitumen and requires specialized loading and unloading equipment, such as tankers.
It is important to use appropriate equipment and follow safety protocols during the transportation and storage of VG Bitumen in any packaging method. Additionally, adherence to manufacturer’s guidelines and local regulations is essential for the safe handling and storage of VG Bitumen.
ADVANTAGES OF VG BITUMEN OVER PENETRAION BITUMEN
- Consistent rutting performance with the same viscosity grade.
- Maintains minimal fatigue cracking at an average yearly temperature of 25°C.
- Reduces potential issues in tender mixes with specified kinematic viscosity values at 135°C.
- Establishes maximum temperature susceptibility via minimum penetration values at 25°C and kinematic viscosity at 135°C.
- Suitable for various temperatures: 60°C for rutting, 25°C for raveling or fatigue, and 135°C for construction.
- Suppliers provide accurate asphalt mixing and temperature data based on viscosity measurements at two temperatures.
- Global preference for asphalt viscosity grading due to its higher accuracy.
- This classification considers bitumen behavior in cold, heat, and fatigue, measured in two phases: penetration at 25°C and viscosity at 60°C and 135°C
COMPARING VG BITUMEN STANDARDS
- Two viscosity measurement methods: Absolute (dynamic) viscosity and kinematic viscosity.
- Absolute viscosity assesses bitumen’s flow resistance at 60°C, while kinematic viscosity calculates viscosity-to-density ratio at 135°C.
- Absolute viscosity predicts bitumen behavior in hot summers, while kinematic viscosity reflects bitumen performance in hot mix asphalt.
- Common grading test results: VG10, VG20, VG30, and VG40, particularly popular in Asian and African nations.
MAINTAINING VISCOSITY GRADE BITUMEN (VG BITUMEN) SURFACES
- Regular inspections for wear, cracks, potholes, and fading road markings.
- Promptly repair minor damage to prevent expansion.
- Resurface when necessary by replacing the top layer.
- Apply sealcoat for protection against UV, rain, and chemicals.
- Ensure proper drainage to prevent water pooling.
- Control traffic to avoid excessive weight on the surface.
- Consider professional assistance for major maintenance tasks, prioritizing longevity and safety.
VISCOSITY GRADE BITUMEN (VG BITUMEN) INSTALLATION
The installation of Viscosity Grade Bitumen (VG Bitumen), particularly for road construction, involves several stages.
The process is generally as follows:
Preparation: The first step is preparing the surface where the bitumen will be laid. This might involve removing any old pavement and leveling or compacting the surface to ensure it is smooth and stable.
Heating: The VG Bitumen needs to be heated before it can be used. This is typically done in a specially designed heater or boiler that can bring the bitumen up to the necessary temperature without overheating it.
Mixing: The heated bitumen is then mixed with aggregate materials to create the asphalt. This mixture is also heated to ensure it remains workable during the installation process.
Laying the Asphalt: The hot asphalt mixture is then spread onto the prepared surface using an asphalt paver. The paver evenly distributes the asphalt, and then heavy rollers compact it to create a smooth, hard surface.
Cooling: Once the asphalt is properly compacted, it needs to cool down before it can be used. During this time, the bitumen hardens and binds the aggregate together, forming a strong, durable road surface.
Sealing: In some cases, the surface may be sealed with a thin layer of bitumen or a bitumen-based sealant. This provides additional weather resistance and can help extend the lifespan of the pavement.
It’s important to note that the specific installation process can vary depending on the type of project, the specific grade of VG Bitumen being used, and local regulations or guidelines. Always follow the manufacturer’s instructions and local standards to ensure a safe and effective installation.
HOW TO SELECT THE PROPER VISCOSITY GRADE BITUMEN?
To select the proper viscosity grade bitumen based on the IS73 standard, the mean temperature of the field should be in one of the divisions of the following table:
| 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 mean temperature is equal to the average temperature of the hottest week of the year which must be for a period of at least 5 years. Although there are days hotter than average in a year, it is important to consider the average temperature as an indicator in this classification. The frequency of hot days and heavy traffic leads to bitumen flow and reduced asphalt life.
TECHNICAL DATA SHEET OF VISCOSITY GRADE BITUMEN
(ASTM D3381-09)
| Property | Units | AC-10 | AC-20 | AC-30 | AC-40 | Test Methods |
|---|---|---|---|---|---|---|
| Viscosity, 140°F (60°C) | P | 1000±200 | 2000±400 | 3000±600 | 4000±800 | ASTM D-2171 |
| Viscosity, 275°F (135°C), Min | cSt | 150 | 210 | 250 | 300 | ASTM D-2171 |
| Penetration, 77°F (25°C), 100g, 5sec, Min | 0.1MM | 70 | 40 | 30 | 20 | ASTM D-5 |
| Flash point, Cleveland open cup, Min | °C | 219 | 232 | 232 | 232 | ASTM D-92 |
| Solubility in trichloroethylene, Min | %Wt | 99 | 99 | 99 | 99 | ASTM D-2042 |
| Tests on residue from thin-film oven test: | ||||||
| Viscosity, 140°F (60°C), Max | P | 5,000 | 10,000 | 15,000 | 20,000 | ASTM D-2171 |
| Ductility, 77°F (25°C), 5cm/min, Min | CM | 50 | 20 | 15 | 10 | ASTM D-113 |
TECHNICAL DATA SHEET OF VISCOSITY GRADE BITUMEN
(IS 73:2013)
| Property | Units | VG-10 | VG-20 | VG-30 | VG-40 | Test Methods |
|---|---|---|---|---|---|---|
| Penetration at 25°C, 100g, 5sec, Min | 0.1MM | 80 | 60 | 45 | 35 | IS 1203 |
| Absolute viscosity at 60°C | P | 800-1200 | 1600-2400 | 2400-3600 | 3200-4800 | IS 1206 (Part 2) |
| Kinematic viscosity at 135°C, Min | cSt | 250 | 300 | 350 | 400 | IS 1206 (Part 3) |
| Flash point (Cleveland open cup), Min | °C | 220 | 220 | 220 | 220 | IS 1448 [P : 69] |
| Solubility in trichloroethylene, Min | %Wt | 99 | 99 | 99 | 99 | IS 1216 |
| Softening point (R&B), Min | °C | 40 | 45 | 47 | 50 | IS 1205 |
| Tests on residue from thin film oven test: | ||||||
| Viscosity ratio at 60°C, Max | - | 4 | 4 | 4 | 4 | IS 1206 (Part 2) |
| Ductility at 25°C, Min | CM | 75 | 50 | 40 | 25 | IS 1208 |
