2025-12-04 | Pankaj Jangid
Deeper of Bitumen Grading in India VG-10, VG-30, VG-40
Introduction
Evolution of Bitumen Grading in India
The Bureau of Indian Standards introduced the first paving grade bitumen under IS 73 in 1950. At that time, bitumen was classified by penetration value. These specifications were later revised in 1962 and again in 1992.
To improve the quality and performance of road surfaces, BIS shifted from penetration grade to viscosity grade classification in July 2006. This update made bitumen selection more scientific because viscosity reflects how thick and fluid bitumen is at different temperatures. Based on the new standards, four viscosity grades were introduced: VG 10, VG 20, VG 30 and VG 40.
Some older tests such as specific gravity, water content, ductility, loss on heating and Fraass breaking point were removed because they did not directly relate to the performance of the product.
IndianOil officially started marketing viscosity grade bitumen from all its refineries in August 2009. After this change, penetration grades were replaced across the country by viscosity grades.
Quick summary of the grades
- VG 10 Softer grade used for very cold regions, surface dressing and bitumen emulsion manufacturing.
- VG 20 For cold climates and high altitude paving.
- VG 30 Most commonly used for general heavy duty pavements with high traffic.
- VG 40 Stiff grade for highly stressed areas like intersections, toll plazas and truck parks.
Why Viscosity Grades Are Important
Viscosity grading is based on how fluid or thick the bitumen is. A higher grade means the bitumen is stiffer. Tests are done at 60°C and 135°C. These temperatures represent real working conditions.
- 60°C is similar to the road temperature during peak summer.
- 135°C is the mixing temperature in the asphalt plant.
Viscosity Grade Bitumen Specification as per IS 73:2013
How Premium Petro supports your project
Premium Petro manufactures bitumen emulsions that are formulated to meet viscosity grade requirements. Our technical team can help you choose the right binder for your pavement based on traffic loads and local temperature conditions. For detailed product specifications and test certificates see our product page and technical datasheets.
Trusted references and standards
For project specification and procurement, follow these official references:
- Bureau of Indian Standards IS 73:2013 for viscosity grade bitumen
- BIS revision history that moved grading from penetration to viscosity in 2006
- Indian refiners and supplier guidance about adoption of viscosity grades
- Ministry of Road Transport and Highways circulars and specifications for road works
Frequently asked questions (FAQ)
Q. Can VG 30 be used everywhere in India?
A. VG 30 is widely used and suits many conditions. For extreme cold or for high stress locations choose VG 10 or VG 40 respectively.
Q. What is the difference between penetration grade and viscosity grade?
A. Penetration grade measures softness at 25°C. Viscosity grade measures flow at 60°C and gives a better idea of performance in hot weather and during mixing.
Q. Do you supply test certificates?
A. Yes. For every batch we can provide test reports showing compliance with IS specifications. You can request certificates from the product page or by contacting our technical team.
Conclusion
Using the correct bitumen grade is important for long lasting roads. At Premium Petro, we manufacture high quality bitumen emulsions that match Indian climatic and traffic conditions. Understanding viscosity grades helps contractors and government agencies select the right material for strong and durable pavements.
If you need guidance in choosing the right bitumen emulsion or bitumen grade for your project, our technical team is always ready to help.