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Oxidized Bitumen 85/25

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Oxidized Bitumen 85/25

What is Oxidized Bitumen 85/25?

Oxidized Bitumen 85/25, also known as Blown Asphalt 85/25, is a hard-grade bitumen produced by blowing hot air through penetration-grade bitumen at elevated temperatures. This controlled air-blowing process increases the softening point and reduces penetration, resulting in a product with a softening point of 85°C and a penetration value of 25 dmm (0.1 mm).

The designation 85/25 refers to:

  • 85 → Softening Point (°C) — the temperature at which the bitumen softens
  • 25 → Penetration Value (dmm) — a measure of hardness at 25°C

Compared to lower grades such as 75/35, Oxidized Bitumen 85/25 is harder and more heat-resistant, making it suitable for demanding industrial and construction applications.

Technical Specifications

Property Value Test Method
Softening Point (R&B) 85 ± 3°C ASTM D36
Penetration (25°C, 100g, 5s) 25 ± 5 dmm ASTM D5
Ductility (25°C) Min. 2.0 cm ASTM D113
Flash Point Min. 250°C ASTM D92
Solubility in CS₂ Min. 99% ASTM D4
Loss on Heating (163°C, 5h) Max. 0.2% ASTM D6
Density at 25°C 1.01–1.06 g/cm³ ASTM D70
Viscosity at 135°C 400–1000 cSt ASTM D2171

Production Process

Oxidized Bitumen 85/25 is manufactured through a carefully controlled air-blowing process:

  1. Penetration-grade bitumen (60/70 or 80/100) is heated to 250–280°C
  2. Compressed air is continuously injected into the bitumen mass
  3. Oxygen reacts with bitumen molecules, increasing molecular weight and rigidity
  4. The process is monitored until the softening point reaches 85°C and penetration drops to 25 dmm
  5. The finished product undergoes quality testing before packaging

Key Applications

1. Roofing Membranes and Felt

Oxidized Bitumen 85/25 is a primary raw material in the production of modified bitumen roofing membranes and bituminous roofing felt for:

  • Flat and low-slope roofing systems
  • APP and SBS modified membranes
  • Built-up roofing (BUR) systems

2. Waterproofing Systems

Widely used in below-grade waterproofing applications including:

  • Basement and foundation waterproofing
  • Tunnels and underground parking structures
  • Bridge deck waterproofing
  • Retaining walls

3. Industrial Pipe Coating

Applied as a protective anti-corrosion coating on metallic pipelines:

  • Oil and gas transmission pipelines
  • Water distribution networks
  • Sewage and drainage systems

4. Bituminous Paints and Primers

Formulated into high-performance bituminous coatings for:

  • Steel structure protection
  • Marine and offshore applications
  • Industrial tanks and vessels

5. Sound Deadening and Vibration Damping

Used in the automotive industry for:

  • Underbody anti-corrosion coatings
  • Sound insulation pads
  • Vibration dampening components

6. Electrical Cable Insulation

Serves as impregnation and filling material in:

  • High-voltage underground cables
  • Armored cables
  • Cable joint and termination boxes

Comparison with Other Oxidized Bitumen Grades

Grade Softening Point Penetration Typical Use
75/25 75°C 25 dmm General waterproofing, coatings
75/35 75°C 35 dmm Roofing, pipe coating, cable insulation
85/25 85°C 25 dmm Roofing membranes, industrial coatings
85/40 85°C 40 dmm Flexible waterproofing, road applications
90/15 90°C 15 dmm High-temp waterproofing, sealants
95/25 95°C 25 dmm High-performance roofing systems

Advantages of Oxidized Bitumen 85/25

  • ✅ High heat resistance — stable performance at temperatures up to 85°C
  • ✅ Superior hardness — excellent mechanical strength and load resistance
  • ✅ Outstanding weathering resistance — UV stable and temperature resistant
  • ✅ Excellent adhesion — strong bonding to concrete, metal, and fabric
  • ✅ High water impermeability — reliable moisture barrier
  • ✅ Chemical resistance — resistant to acids, alkalis, and aggressive soils
  • ✅ Long service life — durable in harsh climatic and industrial environments
  • ✅ Easy application — thermoplastic behavior allows hot-applied installation

Packaging and Storage

Package Type Net Weight Details
Kraft Paper Bag 25 kg Multi-layer, moisture-resistant
Carton Box 25 kg With polyethylene liner
Steel Drum 180 kg Sealed, stackable
Jumbo Bag 1,000 kg For bulk orders
Melt Pour Bulk Available on request

Storage Conditions:

  • Store in a cool, dry place away from direct sunlight
  • Keep away from open flames and heat sources
  • Shelf life: 12 months when stored properly
  • Avoid contact with oxidizing agents

Quality Standards

Oxidized Bitumen 85/25 from RAHA Gilsonite Co. complies with the following international standards:

  • ASTM D312 — Standard Specification for Asphalt Used in Roofing
  • BS 3690 — British Standard for Bitumens for Building and Civil Engineering
  • EN 13304 — European Standard for Oxidized Bitumen
  • DIN 1995 — German Standard for Blown Bitumen
  • ISIRI 118 — Iranian National Standard

Why Choose RAHA Gilsonite Co.?

RAHA Gilsonite Co. is a leading supplier and exporter of Oxidized Bitumen 85/25 with offices in Dubai (UAE), Ankara (Turkey), and Isfahan (Iran). We offer:

  • 🏭 Direct production from our facilities in Iran
  • 🌍 Export to 100+ countries worldwide
  • 📋 Full documentation — COA, MSDS, SGS inspection
  • 🚢 Flexible shipment — FCL, LCL, bulk
  • ⚡ Fast delivery — 2–4 weeks lead time
  • 💬 Technical support — expert team available

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