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Oxidized Bitumen 75/35

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Oxidized Bitumen 75/35

What is Oxidized Bitumen 75/35?

Oxidized Bitumen 75/35, also known as Blown Asphalt 75/35, is a hard-grade bitumen produced by passing hot air through penetration-grade bitumen at high temperatures. This air-blowing process alters the chemical and physical properties of the bitumen, resulting in a product with a softening point of 75°C and a penetration value of 35 dmm (0.1 mm).

The designation 75/35 refers to:

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

Technical Specifications

Property Value Test Method
Softening Point (R&B) 75 ± 3°C ASTM D36
Penetration (25°C, 100g, 5s) 35 ± 5 dmm ASTM D5
Ductility (25°C) Min. 2.5 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 300–900 cSt ASTM D2171

Production Process

Oxidized Bitumen 75/35 is produced through a controlled air-blowing process:

  1. Penetration-grade bitumen (typically 60/70 or 80/100) is heated to 240–270°C
  2. Compressed air is injected into the bitumen mass for several hours
  3. Oxygen reacts with the bitumen molecules, increasing molecular weight and hardness
  4. The process continues until the desired softening point and penetration values are achieved
  5. The final product is tested for quality compliance and packaged

Key Applications

1. Roofing and Waterproofing

Oxidized Bitumen 75/35 is widely used in the manufacturing of roofing felt, modified bitumen membranes, and waterproofing systems for:

  • Flat roofs and terraces
  • Basements and underground structures
  • Bridge decks and tunnels

2. Pipe Coating and Anti-Corrosion

Applied as a protective coating on steel and iron pipelines to prevent:

  • Soil corrosion
  • Water infiltration
  • Chemical attack

3. Electrical Cable Insulation

Used as impregnation material in the production of:

  • Underground cables
  • Armored power cables
  • Telecommunications cables

4. Bituminous Paints and Coatings

Formulated into bituminous paints for:

  • Metal surface protection
  • Marine applications
  • Industrial structures

5. Sound Deadening Pads

Used in the automotive industry for:

  • Underbody coatings
  • Vibration damping pads
  • Anti-corrosion treatments

Comparison with Other Oxidized Bitumen Grades

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

Advantages of Oxidized Bitumen 75/35

  • ✅ Excellent weathering resistance — withstands UV radiation and temperature fluctuations
  • ✅ Good adhesion — bonds well to concrete, metal, and wood surfaces
  • ✅ High water resistance — effective moisture barrier
  • ✅ Thermoplastic behavior — softens when heated for easy application
  • ✅ Chemical resistance — resistant to acids, alkalis, and salts
  • ✅ Long service life — durable performance in harsh environments
  • ✅ Cost-effective — competitive pricing compared to synthetic alternatives

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 75/35 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 75/35 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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