When designing durable asphalt pavements, the type of bitumen you select defines how long the surface will last. Every region, from tropical highways to cold mountain roads, needs a specific binder behavior. At Gold Bitumen, we deliver both Penetration Grade and Viscosity Grade Bitumen, giving engineers and contractors the flexibility to match climate, temperature, and traffic with the right binder.
To choose correctly, it’s essential to know the difference between penetration grade and viscosity grade bitumen—how they’re tested, used, and specified around the world.
Penetration Grade Bitumen – A Traditional Approach
Before modern performance testing was introduced, bitumen quality was judged by its hardness. The penetration test measures how deep a standard needle can enter a bitumen sample at 25 °C under a fixed load for five seconds. The result, given in tenths of a millimeter, becomes the grade.
30/40 and 40/50: hard grades for hot climates and heavy traffic.
60/70: balanced binder for moderate to warm zones.
80/100 and 100/120: softer binders for cold weather conditions.
Key Takeaways
Indicates hardness, not flow behavior.
Works best for hot or temperate climates.
Still preferred where ASTM D5 and British Standards are followed.
Economical and simple to test, though less precise for performance prediction.
Viscosity Grade Bitumen – A Performance-Based System
Viscosity Grade Bitumen (VG Bitumen) represents a modern method of classification that focuses on how bitumen flows rather than how soft it feels. It measures resistance to flow (viscosity) at two critical temperatures—60 °C (service temperature) and 135 °C (mixing temperature).
Because viscosity testing reflects real paving conditions, it allows engineers to predict road behavior more accurately.
Available Grades: VG-10, VG-20, VG-30, and VG-40.
Key Takeaways
Defines flow resistance under real conditions.
Offers better thermal stability and durability.
Recommended in IS 73:2013 and ASTM D2171 standards.
Widely used in modern highways and airports.
Global Adoption – Who Uses What
Different regions apply different grading systems based on climate, infrastructure age, and national standards.
Countries Using Penetration Grades
Many Middle Eastern, African, and Asian countries—including Iran, UAE, Saudi Arabia, Oman, Kenya, Tanzania, and Indonesia—still rely on penetration grades such as 60/70 and 80/100.
Their road standards were built around older British and ASTM methods, and because these regions enjoy relatively stable warm climates, penetration grades remain sufficient for everyday asphalt work.
Countries Using Viscosity Grades
In contrast, nations such as India, Bangladesh, Nepal, and Sri Lanka have replaced penetration grading with viscosity systems aligned with MoRTH and Indian Roads Congress (IRC) specifications.
Meanwhile, Malaysia, Vietnam, South Korea, Brazil, and Qatar increasingly specify VG Bitumen for expressways and industrial pavements, valuing its consistency, resistance to rutting, and superior control in production.
Main Differences at a Glance
| Feature | Penetration Grade | Viscosity Grade |
|---|---|---|
| Testing Basis | Depth of needle penetration | Flow resistance (viscosity) |
| Temperature for Test | 25 °C | 60 °C & 135 °C |
| Predictive Accuracy | Moderate | Excellent |
| Temperature Susceptibility | High | Low |
| Preferred Climates | Warm / moderate | All climates |
| Rutting Resistance | Average | Very high |
| Usage Trend | Traditional method | Modern global standard |
Why Viscosity Grades Are Replacing Penetration Grades
The main limitation of penetration grading is its inconsistent prediction of field performance.
As road networks handle higher loads and more temperature variation, viscosity grading offers better control, reliability, and uniformity. It enables highway authorities to design mixes that maintain stability in extreme heat while resisting cracks in colder conditions.
Nevertheless, penetration grades continue to serve local and regional projects where cost, simplicity, and tradition guide specifications.
Selecting the Right Grade for Your Project
Bitumen performance depends on climate and traffic conditions. Below are typical recommendations:
Cold or high-altitude regions: Pen 80/100 or VG-10.
Warm climates / medium traffic: Pen 60/70 or VG-20.
Tropical zones / heavy traffic: Pen 40/50 or VG-30.
Extreme heat / industrial pavements: Pen 30/40 or VG-40.
Choosing the right grade ensures smooth compaction, strong adhesion with aggregates, and long-term pavement stability.
Gold Bitumen – Your Global Supplier for All Grades
At Gold Bitumen, we manufacture and export both Penetration Grade and Viscosity Grade Bitumen from ISO-certified refineries.
Each batch undergoes penetration, viscosity, softening-point, and ductility tests to guarantee full compliance with ASTM, EN, and IS standards.
Why Buyers Prefer Gold Bitumen
New steel drums, bitutainers, and jumbo bags for secure packaging.
Fast shipping through UAE and Iran export terminals.
Stable pricing and customized grades for project specifications.
Technical assistance from our engineering support team for climate-specific recommendations.
Whether your project is a regional road or a cross-border expressway, our quality and logistics network ensure you receive consistent, high-performing bitumen every time.
Frequently Asked Questions
1. Which grade lasts longer on heavy-traffic highways?
Viscosity Grade Bitumen (especially VG-30 or VG-40) performs better under heavy loads due to higher temperature stability.
2. Can I directly substitute Pen 60/70 with VG-30?
Yes, the two are roughly equivalent, but always confirm with project specifications before replacement.
3. Why haven’t all countries moved to VG Bitumen yet?
Some regions keep using penetration grades because of existing lab setups, specification history, or cost advantages. The shift is gradual but continuous.
Final Thoughts
The difference between penetration grade and viscosity grade bitumen lies in their testing methods and field performance. Penetration grades remain practical where simplicity matters, while viscosity grades deliver the precision required by today’s advanced road systems.
As infrastructure standards rise, Gold Bitumen continues to lead the market by offering both systems with guaranteed quality, reliable logistics, and expert technical support—helping every project build roads that last longer and perform better.