Oxidized Bitumen

What is Oxidized Bitumen?

Oxidized bitumen, also known as blown bitumen, is a specialized form of bitumen created through a process of air blowing. This variant, characterized by low penetration and a high softening point, is utilized in various manufacturing processes and as a sealing agent. Compared to pure bitumen, oxidized bitumen exhibits lower penetration, indicating it is softer and less susceptible to temperature fluctuations.

The designation for oxidized bitumen is “R,” denoting its softening and penetration characteristics. For instance, R80/25 bitumen has a softening point of 80 degrees Celsius and a penetration value of 25.

How is Oxidized Bitumen Produced?

Oxidized bitumen is manufactured by blowing air through petroleum bitumen, a process that enhances its softness and elasticity, particularly in cooler conditions. During the final purification stage, hot air is injected into pure bitumen, resulting in a rubber-like grade of bitumen. 

This procedure involves passing hot air, typically between 200 to 300 degrees Celsius, into a chamber filled with bitumen via perforated pipes.

The interaction of hot air and bitumen leads to a chemical reaction where hydrogen atoms from the bitumen’s hydrocarbon molecules combine with oxygen, forming water and initiating a sintering process that yields oxidized bitumen.

Applications of Oxidized or Blown Bitumen:

Oxidized bitumen is utilized in the oil and gas industries for coating materials on pipelines and their joints. It also finds use in the electrical industry as a sealant for wire coatings. In the construction sector, blown bitumen is integral to waterproofing applications, such as producing roofing felt sheets for factories.

Additionally, oxidized bitumen is employed in bitumen and asphalt plants for road surfacing and serves as a key component in sound-dampening layers for acoustic insulation.

In essence, oxidized (blown) bitumen is primarily used in industrial applications, including waterproofing for roofs and floors, tire manufacturing, pipe coating, and paint formulation.

Properties of Oxidized Bitumen:

Oxidized bitumen is classified based on its softening point and penetration degree. For example, 85/40 bitumen has a softening point of 85±5 °C and a penetration degree of 40±5 dmm.

These types of bitumen adhere to standards concerning solubility and heat-related weight loss. Oxidized bitumen has a significantly higher softening point than corresponding penetration bitumen, resulting in greater thermal sensitivity. For instance, their penetration index is considerably higher, ranging from +2 to +8.

Types of Oxidized Bitumen:

There are various grades of oxidized bitumen, each suited to specific applications.

Some common grades include:

  • Oxidized bitumen R75/30
  • Oxidized bitumen R95/25
  • Oxidized bitumen R85/25
  • Oxidized bitumen R90/40
  • Oxidized bitumen R105/35
  • Oxidized bitumen R115/15


These grades are widely used in industrial applications such as waterproofing, tire production, pipe coating, and paint manufacturing.

For instance, oxidized bitumen 75/30 is produced by polymerizing flexible bitumen in response to air exposure. With a penetration grade of 30 and a softening point of 75, this grade is employed across various industries, including road construction, hydropower projects, roofing, and electrical applications.

Oxidized bitumen 95/25 is a standard grade used in construction for purposes such as steel pipe covering and waterproofing. It is derived from blowing hot air through penetrating bitumen to achieve the desired specifications.

Availability and Ordering:

Grand Petroleum Company provides Penetration Grade Bitumen at competitive prices, available in both drum and bulk formats for local and global markets. To inquire about the latest pricing or to initiate an order, Contact Grand Petroleum Sales Department.

Oxidized Bitumen R85/25

Oxidized bitumen 85/25 is the most widely used type of bitumen in the construction industry, and the main grade of this type of bitumen is 85/25 bitumen.

Oxidized bitumen 85/25 has a softening point of 85 and its penetration degree is 25. Among the types of oxidized bitumen, this bitumen is widely used and very popular in the market for paving, road maintenance, embankments, dams in water projects, the roofing industry, flooring, tile of bathrooms, coating pipelines, lithium battery, glue for laminate boards, etc.

Oxidized Bitumen R85/40

Oxidized bitumen 85/40 is based on petroleum bitumen made by blowing 60/70 bitumen with very hot air.

Oxide bitumen 85/40 is used in making waterproofing layers, asphalt clays, sealing roofs, mastics, pipe coating, paint, even road asphalt, and many other things.

Oxidized Bitumen R105/35

Oxidized bitumen R 105/35, which is the result of the oxidation of penetrating bitumen exposed to very hot air, is completely hard at ambient temperature and requires a lot of heating to use it. 

Oxidized bitumen 105/35 is used in civil engineering, construction, road operations, crack sealing, road repairing, roofing, flooring, coating, protecting pipelines, insulation, and sealing buildings. 

Also, R105/35 is used in petroleum operations for coating oil and gas pipelines as a carriage sealant and soundproofing material in cars, in very hot or very cold weather conditions.

Oxidized bitumen 105/35’s in combination with gilsonite can maintain asphalt stability. Also, its combination as we said with gilsonite can prevent deformation and crack due to changing climates.

Oxidized Bitumen R115/15

Oxidized bitumen 115/15 is obtained from the reaction of hot bitumen with oxygen. Bitumen aeration is a process in which hot liquid bitumen is exposed to air.

Blown bitumen 115/15 is used in making waterproofing layers, asphalt clays, sealing roofs, mastics, pipe coating, paint, even road asphalt, and many other things.



Oxidized Bitumen Grade







Softening Point Temperature ©








Penetration at 25 C (dmm)








Thermal Loss Percentage

ASTM D1754







Solubility in trichloroethylene

ASTM D2042







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