Types of viscosity grade of bitumen and applications

Bitumen of Viscosity Grade (Asphalt) is the most commonly used asphalt in road construction and for asphalt paving projects with excellent properties. When producing hot mix asphalt, VG Bitumen is usually used. The most commonly used bitumen is viscosity grade bitumen, which is available in Vira Petroleum, VG bitumen exporter, in four different types: VG10, VG20, VG30, and VG40. Viscosity is a measure of the hardness of bitumen. The higher the number in a viscosity grading system, the harder the bitumen. AASHTO M226-80 and ASTM D3381-09 specify the viscosity grade of bitumen. The viscosity of VG Bitumen specifications is expressed in degrees Celsius (140°F).

Advantages of viscosity grade bitumen

Since VG bitumen is tested more thoroughly by experts in two phases than penetration bitumen, it is now used instead. In the beginning, the penetration of bitumen was measured at 25 degrees C, which is the average temperature, however, not all tests are reliable in hot weather, so they measured bitumen viscosity at 60 degrees C and 135 degrees C. The results of these tests indicate:

  1. Time and money can be saved by minimizing the number of tests; penetration looks at 14 tests, while IS lists 7 tests for VG bitumen.
  2. VG bitumen has a similar rutting performance under hot summer conditions, unlike penetration grade bitumen.
  3. In addition to its suitability for a wide range of temperatures, VG bitumen can be determined to be temperature-susceptible; 25 *C for fatigue cracking and 135 *C for construction.
  4. VG bitumen is designed for high-traffic roads
  5. In general, pavements made from VG Bitumen have a longer life because the viscosity at 135 C gives a good indication of mixing and compaction temperatures, thus extending the pavement life.
  6. Construction tender mix potential can be minimized by specifying a minimum kinematic viscosity value at 135 C


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Disadvantages of viscosity grade bitumen

  1. Viscosity of thin-film oven test residues can vary greatly based on the AC grading system. Because of this, despite the fact that asphalt binders are of the same AC grade, they may behave differently.
  2. Compared to penetration tests, VG bitumen costs more time and money.
  3. It is unclear whether the principal grading (done at 25°C (77°F)) is an accurate representation of asphalt binder rheology at low temperatures.






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Applications of VG bitumen

There are several types of viscosity grade bitumen, each with different applications, depending on two important factors, such as weather and traffic conditions. As of today, VG bitumen has been considered for more than 250 different applications, making it impossible to replace it with other materials.

Bitumen VG-30 is most commonly used for the construction of heavy-duty bitumen pavements that are designed to handle heavy traffic loads. Furthermore, VG30 is widely used in the production of cutback bitumen, waterproofing materials, and in road and building construction subsidiary. Additionally, it can be used in place of 60/70 Penetration grade. In hot and rainy weather when paving can be challenging, as well as in milder regions, it is an excellent choice.

Viscosity test

Before the construction of roads, it is important to conduct a viscosity test of a bitumen sample. The viscosity of bitumen is a measure of its fluidity. By measuring the fluidity of bitumen at a certain temperature, it can ensure the quality of the binder. A bituminous binder used in pavement will only serve as a lubricant if it has a much lower viscosity value. Due to this, it will not aid in particle binding, which is its primary purpose.

By restricting the flow of a highly viscous binder, voids between aggregates cannot be filled and the binder cannot spread during pavement construction. Additionally, the process will require more effort compared to traditional methods, and a heterogeneous mix may result. Highly viscous bitumen can also affect workability. In order to achieve a uniform coating and fill up the space between aggregate particles, a binder of appropriate viscosity must be selected.

What is bitumen viscosity?

Grading of viscosity are used to categorize bitumen in terms of its degree of fluidity. Generally speaking, solid Bitumen has a higher grade of viscosity. As part of the Viscosity Grade, Viscosity tests are conducted at a temperature of 60°C and a temperature of 135°C, representing, respectively, the summer temperature of the roadway and the mixing temperature.

Which bitumen grade should be used in snow?

In India, Vira Petroleum, which supplies bitumen in India, describes VG-10 bitumen as the softest grade. Snow bound regions use this type of bitumen most commonly. The low viscosity of VG-10 makes it especially suitable for coatings and spraying applications.

What are the grades of bitumen?

In the 100-year history of bitumen grading, penetration grading is used. Before 2006, bitumen grades 60 to 70 were most commonly used in India. As follows:
• 40-50 which is the hardest bitumen grade
• 60 -70
• 85-100
• 120-150
• 200-300 which is the softest grade of bitumen

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