Oxidized Bitumen (Blown Bitumen)
Oxidized Bitumen — also referred to as Blown Bitumen or Blown Asphalt — is a specialized, high-performance grade of bitumen produced through a carefully controlled air-blowing process. By passing hot air through penetration-grade bitumen at temperatures of 250–300°C, the material undergoes a fundamental molecular transformation: its softening point rises significantly, its penetration value drops, and it develops a harder, more elastic, gel-like structure that sets it apart from conventional bitumen grades.
The outcome is a thermally stable, chemically resistant, and fully waterproof industrial binder — trusted for decades across roofing, waterproofing, pipe coating, automotive manufacturing, and civil engineering projects worldwide.
RAHA Gilsonite Co. supplies a full range of Oxidized Bitumen grades, manufactured to international standards and exported globally from production facilities in Iran, with commercial offices in Dubai and Ankara.
How Oxidized Bitumen Is Made
The production of Oxidized Bitumen follows either a continuous or staggered air-blowing process. Penetration-grade bitumen is heated to approximately 250–300°C in a refinery blowing tower. A steady, controlled flow of hot air is then injected through the molten feedstock. The oxygen reacts with the bitumen molecules, increasing molecular weight, raising viscosity, and converting the binder into a significantly harder and more durable material.
Each grade is designated by two numbers. The first number indicates the mid-point of the softening point range in degrees Celsius, and the second indicates the mid-point of the penetration range in tenths of a millimeter (dmm). For example, Oxidized Bitumen 115/15 has a softening point of approximately 115°C and a penetration value of approximately 15 dmm. All grades are tested and verified according to ASTM D36 for softening point and ASTM D5 for penetration before release.
Key Technical Properties
High Softening Point
Depending on the grade, the softening point of Oxidized Bitumen ranges from around 80°C up to over 150°C — far higher than standard penetration-grade bitumen. This thermal resilience makes it the material of choice wherever heat resistance and dimensional stability under load are critical.
Low Penetration Value
With penetration values typically between 5 and 40 dmm, Oxidized Bitumen is a significantly harder binder that resists deformation under traffic loads, mechanical stress, and sustained pressure.
Reduced Temperature Sensitivity
One of the defining advantages of Oxidized Bitumen is its high penetration index, which ranges from +2 to +8. This means the material is far less susceptible to softening in summer heat or hardening in cold conditions compared to conventional road-grade bitumen — a critical property in industrial applications exposed to variable climates.
Rubbery and Elastic Structure
The air-blowing process gives the bitumen a semi-polymeric, gel-like molecular structure. This elasticity allows the material to flex under movement without cracking, making it highly effective in sealing, membrane, and joint-filling applications.
Full Waterproofing Performance
Oxidized Bitumen is inherently impermeable to moisture. Its chemical stability makes it resistant to acids, alkalis, salts, and a wide range of corrosive agents — without any need for additional chemical treatment.
Long-Term Durability
Field performance data from pipeline and roofing applications spanning over 80 years confirms that Oxidized Bitumen provides exceptional long-term protection. When applied correctly, it resists UV degradation, aging, and chemical attack for decades.
Industrial Applications
Roofing and Waterproofing Membranes
The single largest application for Oxidized Bitumen is roofing. It serves as the bonding agent in roofing felt membranes and as a hot-applied waterproofing layer on flat roofs, terraces, podium decks, and building foundations. Roofing accounts for nearly 50% of global bitumen membrane consumption, a market currently valued at over USD 11 billion and projected to reach USD 16.2 billion by 2035.
Pipeline and Pipe Coating
Oxidized Bitumen has been the world’s most trusted pipe coating material for over 80 years. Applied as a hot bitumen enamel system in accordance with AWWA C203 and DIN 30673, it delivers unmatched corrosion resistance, waterproofing, and adhesion to steel for water, gas, oil, and industrial pipelines. The global pipe coating market was valued at USD 10.29 billion in 2025 and is growing steadily, driven by infrastructure investment across Africa, the Middle East, and Asia.
Industrial Paints and Anti-Corrosion Coatings
Oxidized Bitumen is a key raw material in bitumen-based industrial paints and protective coatings. It is used in anticorrosive paints for metal structures, automotive underbody coatings, car chassis protection, and bitumen coatings for gas and sewage pipes. Its high nitrogen content enhances adhesion and UV stability, while its zero penetration value delivers the hardness and body that formulation chemists require.
Automotive and Sound Dampening
Vehicle manufacturers rely on Oxidized Bitumen as an undercarriage sealant and acoustic dampening material. It provides simultaneous waterproofing, dustproofing, and noise reduction — properties that are particularly critical for underbody protection in commercial and passenger vehicles.
Joint Filling and Construction Sealants
Oxidized Bitumen is ideal for sealing saw cuts, expansion joints, and structural gaps in pavements, runways, and industrial floors where minimal movement is expected. Its high softening point prevents bleeding or flow at elevated service temperatures, making it a reliable long-term sealant.
Hydraulic Engineering and Canal Lining
In water infrastructure projects, Oxidized Bitumen is applied as a lining material for irrigation canals, dam facings, and hydraulic structures. Its impermeability and chemical resistance to soil salts and agricultural chemicals make it particularly suitable for large-scale water transmission projects in the Middle East, Central Asia, and Africa.
Carpet Backing and Acoustic Panels
Lower-softening-point grades such as 90/40 are widely used in the manufacture of carpet backing, acoustic dampening panels, and flooring compounds. The material provides adhesion, dimensional stability, and sound absorption properties valued in the construction and interior finishing industries.
Marine and Oil Industry Applications
Oxidized Bitumen is formulated into bituminous marine mastic for use in oil and gas pipeline joints, both onshore and offshore. It also serves as an undersealing agent beneath Portland cement concrete pavements in hydraulic and heavy infrastructure projects.
Electrical and Cable Industry
In the electrical sector, Oxidized Bitumen is used as an adhesive in laminated insulation boards, for sealing electrical junction boxes, and in certain cable insulation applications — valued for its dielectric properties and moisture resistance.
Available Grades
RAHA Gilsonite Co. produces and exports the following standard Oxidized Bitumen grades. Custom grades are available upon request to meet project-specific technical requirements.
- Oxidized Bitumen 150/5 — Softening point approximately 150°C, penetration approximately 5 dmm. The hardest standard grade, used in demanding pipe coating and high-temperature industrial applications.
- Oxidized Bitumen 115/15 — Softening point approximately 115°C, penetration approximately 15 dmm. Widely used in roofing felts, pipe coating, piling anti-slip layers, and sound dampening materials.
- Oxidized Bitumen 105/35 — Softening point approximately 105°C, penetration approximately 35 dmm. A versatile mid-range grade suited to waterproofing membranes and pipeline systems.
- Oxidized Bitumen 105/15 — Softening point approximately 105°C, penetration approximately 15 dmm. Used in industrial coatings, sealants, and protective applications requiring high heat resistance.
- Oxidized Bitumen 95/25 — Softening point approximately 95°C, penetration approximately 25 dmm. One of the most widely specified grades globally, preferred for waterproofing, roofing, and marine applications. Compliant with AWWA C203 for standard pipeline coating systems operating below 70°C.
- Oxidized Bitumen 90/40 — Softening point approximately 90°C, penetration approximately 40 dmm. Favored in carpet backing, acoustic panels, and flexible waterproofing applications.
- Oxidized Bitumen 90/15 — Softening point approximately 90°C, penetration approximately 15 dmm. Applied in industrial protective coatings and hard surface treatments.
- Oxidized Bitumen 90/10 — Softening point approximately 90°C, penetration approximately 10 dmm. Applied in hard protective coatings and industrial surface treatments.
- Oxidized Bitumen 85/40 — Softening point approximately 85°C, penetration approximately 40 dmm. Popular in several European markets including Scandinavia, used in flexible membrane and waterproofing systems.
- Oxidized Bitumen 85/25 — Softening point approximately 85°C, penetration approximately 25 dmm. A widely used grade in industrial roofing, waterproofing, and pipe coating applications.
Quality Standards and Testing
Every shipment of Oxidized Bitumen from RAHA Gilsonite Co. is produced and tested in accordance with leading international standards.
Softening point is measured using the Ring and Ball method per ASTM D36, the globally recognized benchmark for thermal stability classification in bitumen. Penetration is tested per ASTM D5, confirming the hardness and grade of each batch. Flash and fire point safety data is provided per ASTM D92. Pipeline coating systems comply with AWWA C203 and DIN 30673. European buyers can request product conformity with EN 13304, the European framework for oxidized bitumen specifications.
Batch-specific Certificates of Analysis are provided with every order. Customers are encouraged to request consistency data across multiple batches — not just a single COA — as repeatability is the true indicator of supplier reliability in industrial procurement.
Packaging and Shipping
Oxidized Bitumen is available in the following packaging formats, all compliant with international export standards:
- Kraft paper bags (25 kg)
- Carton boxes (25 kg)
RAHA Gilsonite Co. ships globally. Our export hubs serve customers across the Middle East, Europe, Asia, and Africa, with dedicated logistics support coordinated through our offices in Dubai and Ankara.
Why Source from RAHA Gilsonite Co.?
RAHA Gilsonite Co. is a member of RAHA Group, with decades of production and export experience in bitumen and natural asphalt products. We offer consistent quality backed by rigorous QC, a full range of standard and custom grades, responsive technical support, and the commercial infrastructure to handle large-volume international orders efficiently.
For technical data sheets, product samples, custom grade inquiries, or export pricing, contact our team today.
Contact Us
Have a question or ready to place an order? Our team is available across three continents to assist you with technical data sheets, product samples, custom grade inquiries, and export pricing. Visit our Contact Page to get in touch.
Frequently Asked Questions
What is Oxidized Bitumen?
Oxidized Bitumen, also known as Blown Bitumen, is a grade of bitumen produced by blowing hot air through penetration-grade bitumen at high temperatures. This process increases its softening point, reduces its penetration, and gives it a more elastic, thermally stable structure suited to industrial applications.
What is the difference between Oxidized Bitumen and regular bitumen?
Unlike penetration-grade bitumen used in road paving, Oxidized Bitumen has a significantly higher softening point, lower penetration value, and reduced temperature sensitivity — making it suitable for roofing, waterproofing, pipe coating, and industrial applications rather than road construction.
What grades of Oxidized Bitumen does RAHA Gilsonite Co. supply?
We supply Oxidized Bitumen 150/5, 115/15, 105/35, 105/15, 95/25, 90/40, 90/15, 90/10, 85/40, and 85/25. Custom grades are also produced on request.
How is Oxidized Bitumen packaged?
We supply Oxidized Bitumen in kraft paper bags (25 kg) and carton boxes (25 kg), compliant with international export standards.
What international standards apply to Oxidized Bitumen?
Key standards include ASTM D36 (softening point), ASTM D5 (penetration), ASTM D92 (flash point), AWWA C203 and DIN 30673 (pipe coating), and EN 13304 (European oxidized bitumen specification).
What is the maximum safe handling temperature for Oxidized Bitumen?
The maximum safe handling temperature is 230°C. Blown grade bitumen should be broken into small pieces and heated slowly to an application temperature of 220–230°C to ensure even melting and avoid localized overheating.
