Bitumen Penetration 40/50

Penetration Grade Bitumen 40/50 is one of the most common grades of traditional bitumen, classified based on the penetration of a standard needle into the bitumen at 25°C. This type of grading is typically used in conventional asphalt paving and road construction.

Meaning of the 40/50 in Penetration Bitumen

• First number 40: Minimum penetration of the needle in tenths of a millimeter (0.1 mm)
• Second number 50: Maximum penetration of the needle

This means that if a standard 100-gram needle is placed on the bitumen sample for 5 seconds, the penetration depth will range from 40 to 50 tenths of a millimeter.

Properties of Penetration Bitumen 40/50

Property	Value / Description
Hardness	Relatively hard, harder than 60/70
Softening Point	Lower than softer grades, better resistance to high temperatures
Flexibility	Less flexible than softer grades (e.g., 85/100)
Rutting Resistance	High
Application	Suitable for heavy-traffic roads or hot climate areas

 

Applications of 40/50 Bitumen

• Road construction in warm or temperate regions with heavy traffic
• Base and surface asphalt layers
• Railways or industrial projects requiring hard bitumen
• Additive in blown bitumen production

Bitumen Grade	Penetration Range	Characteristic	Suitable For
30/40	30–40	Very hard	Extremely hot regions and industrial roads
40/50	40–50	Hard	High-traffic roads and hot climates
60/70	60–70	Medium	Ordinary roads, temperate regions
85/100	85–100	Soft	Cold regions, light asphalt, and patching

Important Notes

• 40/50 is harder than 60/70 and offers better resistance in hot climates.
• In extremely cold winters, this grade may crack and is less recommended.
• This type of bitumen is typically used in Hot Mix Asphalt (HMA) and is suitable for high-traffic projects.