Oxidized Bitumen 115/15 (Blown Asphalt 115/15)
Oxidized Bitumen 115/15 — also referred to as Blown Asphalt 115/15 or Blown Bitumen 115/15 — is a hard-grade industrial bitumen produced through a controlled air-blowing process applied to vacuum-bottom petroleum bitumen at temperatures exceeding 250°C. The designation “115/15” directly encodes its two defining parameters: a ring-and-ball softening point of 115°C and a penetration value of 15 dmm at 25°C — confirming its classification as a high-rigidity, low-thermal-sensitivity binder engineered for demanding industrial, roofing, and waterproofing applications.
What Is Oxidized Bitumen 115/15?
Oxidized bitumen is classified by Eurobitume — the European Bitumen Association — as a distinct product category, separate from standard penetration-grade and polymer-modified bitumens. According to Eurobitume’s technical documentation, the air-blowing process alters the physical properties of straight-run bitumen to yield a material suited for specific industrial and roofing applications that conventional paving grades cannot serve.
At the molecular level, the transformation involves a cascade of oxidative reactions. Research published in ACS Energy & Fuels (2023) confirms that controlled oxidation converts lighter aromatic and resin components into heavier polar species, with the asphaltene fraction increasing by more than 75% — driving the rise in viscosity, hardness, and softening point that defines the 115/15 grade. A 2025 study in ScienceDirect / Construction and Building Materials further documents that the process is irreversible: it raises the average molecular weight of the binder, increases polar functional group content, reduces plasticity, and enhances the gel-like colloidal structure of the material.
The feedstock is typically penetration-grade bitumen 60/70 derived from vacuum-bottom (VB) refinery residues. Hot air at controlled pressure is injected through perforated pipes into the bitumen column; as hydrogen atoms in the hydrocarbon molecules combine with oxygen to form water and carbonyl/sulfoxide groups, the material hardens progressively until the target 115/15 specification window is reached.
Key Technical Properties
The combination of a high softening point (110–120°C) and a very low penetration value (10–20 dmm) places Oxidized Bitumen 115/15 at the harder end of the oxidized bitumen spectrum. Its Penetration Index (PI) is significantly higher than road-construction grades (PI > 2), reflecting its gel-structured colloidal architecture — a direct consequence of elevated asphaltene content — which confers low thermal susceptibility.
- Thermal Stability: Remains dimensionally stable at surface temperatures encountered in hot-climate roofing and pipeline environments. Critical for installations in the Middle East, South Asia, and sub-Saharan Africa where ambient temperatures regularly exceed 60°C.
- Chemical Resistance: Strong resistance to acids, alkalis, and salts — suitable for use in harsh chemical environments including industrial flooring, pipeline coatings, and marine applications.
- Waterproofing Performance: Completely waterproof with a flexible and chemically stable composition, enabling long-lasting protection against moisture infiltration in both below- and above-grade construction.
- Superior Adhesion: Strong adhesive properties make it effective in binding materials together in roofing, industrial, and construction assemblies.
- Long-Term Durability: High resistance to aging and environmental degradation ensures reliable long-term performance in exposed and buried applications alike.
International Standards Compliance
Oxidized Bitumen 115/15 supplied by Gilsonite Co. is manufactured and tested against the following internationally recognised frameworks:
- ASTM D36 — Softening Point by Ring-and-Ball
- ASTM D5 — Penetration of Bituminous Materials
- ASTM D113 — Ductility of Asphalt Materials
- ASTM D92 — Flash and Fire Points by Cleveland Open Cup
- ASTM D6 — Loss on Heating of Oil and Asphaltic Compounds
- ASTM D4 — Bitumen Content
- BS EN 13304:2009 — Framework for Specification of Oxidised Bitumens (European Standard)
About BS EN 13304:2009: This is the governing European standard published by the British Standards Institution and adopted identically across EU and EEA member states as DIN EN 13304 (Germany), NS EN 13304 (Norway), and EVS EN 13304 (Estonia). It provides the definitive framework for the specification of oxidised bitumens used mainly in roofing, waterproofing, adhesives, and thermal and phonic insulations. Products are graded by a combination of ring-and-ball softening point and penetration at 25°C, expressed as multiples of 5 — making 115/15 a fully compliant, standard-defined grade within this European framework.
Production Process
- Feedstock Selection: Vacuum-bottom (VB) residue from petroleum vacuum distillation is selected as the base material. Only crudes with suitable paraffinic-to-naphthenic composition yield an oxidized product with stable 115/15 characteristics.
- Pre-Heating: The base bitumen is heated to 220–260°C inside a controlled blowing tower. Temperature uniformity is critical to ensure consistent asphaltene polymerization throughout the batch.
- Controlled Air Injection: Hot compressed air is injected through perforated pipes at the base of the oxidizer. Oxygen reacts with hydrocarbon chains, triggering dehydrogenation, ketone formation, and asphaltene polymerization — progressively hardening the material.
- QC Monitoring: Batch-level softening point and penetration testing is conducted throughout the blowing cycle. Production stops when both parameters fall simultaneously within the 115/15 specification window.
- Packaging and Independent Inspection: The product is decanted into drums, Kraft bags, or polyamide bags under temperature control. A third-party international inspector verifies quality and quantity at the time of shipment loading.
Applications of Oxidized Bitumen 115/15
According to the International Bitumen Emulsion Federation (IBEF), bitumen has over 250 known applications globally, with oxidised grades serving primarily the industrial, roofing, and waterproofing sectors — distinct from penetration grades used in road paving. Oxidized Bitumen 115/15 covers the following application areas:
Construction and Waterproofing
- Waterproofing membranes for flat and low-slope roofs
- Below-grade damp-proofing for foundations and basements
- Bridge deck and tunnel waterproofing systems
- Reservoir, dam, and hydraulic structure lining
- Expansion joint filling and crack repair in concrete structures
- Eco-roofing and roof garden substrate waterproofing
Industrial and Pipeline
- Anti-corrosion pipe coating for oil and gas pipelines
- Electric cable joint protection and insulation
- Bituminous marine mastic for offshore and port applications
- Industrial flooring in factories and warehouses
- Piling anti-slip layer compound
- Transformer and electrical component insulation
Roofing and Insulation
- Roofing felt manufacture and lamination
- Sound-dampening and phonic insulation underlay felts
- Thermal insulation membrane production
- SBS-modified membrane bonding compound
- Bituminous membrane sheet (isolation sheet) production
Automotive and Specialty Manufacturing
- Vehicle underbody and undercarriage sealants
- Carpet backing and synthetic turf base
- Asphalt-based metal corrosion protection paints and lacquers
- Adhesive bonding in electrical laminates
- Paper, pulp, board, and textile processing treatments
- Sealing compounds for batteries and accumulators
Oxidized Bitumen 115/15 — Technical Specification Sheet
| Property | Test Method | Specification |
|---|---|---|
| Penetration @ 25°C, 100g, 5s (0.1 mm) | ASTM D5 / EN 1426 | 10 – 20 |
| Softening Point — Ring & Ball (°C) | ASTM D36 / EN 1427 | 110 – 120 |
| Ductility @ 25°C (cm) | ASTM D113 | ≥ 2 |
| Loss on Heating (wt%) | ASTM D6 | ≤ 0.2 |
| Flash Point — Cleveland Open Cup (°C) | ASTM D92 | ≥ 230 |
| Solubility in Carbon Disulfide CS₂ (wt%) | ASTM D4 | ≥ 99 |
| Density @ 25°C (g/cm³) | ASTM D70 | ≈ 1.05 |
| Spot Test | AASHTO T102 | Negative |
| Appearance | Visual | Black solid / semi-solid |
| European Standard Compliance | BS EN 13304:2009 | Compliant |
All values are guaranteed by batch-level QC testing. Third-party international inspection is available at time of loading. Full TDS and MSDS documentation provided upon request.
Packing of Oxidized Bitumen 115/15
Gilsonite Co. supplies Oxidized Bitumen 115/15 with loading from Jebel Ali Port, Dubai (UAE) and Iskenderun Port (Turkey). The following packing formats are available:
- 25 kg PP Bag — Palletized & Shrink Wrapped
- 25 kg Kraft Bag — Palletized & Shrink Wrapped
- 25 kg Carton Box — Palletized & Shrink Wrapped
Container Loading: A standard 20ft FCL container holds approximately 22–23 metric tons of Oxidized Bitumen 115/15.
Safe handling note: The maximum safe handling temperature is 230°C and must not be exceeded. Because bitumen is a poor conductor of heat, the heating phase of packaged material must be carefully controlled to prevent localized overheating. Packaged product is typically heated and melted in site boilers prior to application.
Pricing is available on FOB, CFR, and CIF terms. Contact our export team for a quotation.
Frequently Asked Questions
What does the designation 115/15 mean?
The two numbers encode the product’s core physical parameters as defined by both ASTM standards and European Standard BS EN 13304:2009. The first number — 115 — is the ring-and-ball softening point in degrees Celsius: the temperature at which the bitumen transitions from a rigid solid to a soft, pliable state. The second number — 15 — is the penetration value at 25°C in units of 0.1 mm (dmm): a standard needle penetrates the material only 1.5 mm under defined test conditions, confirming this is a hard, low-plasticity grade. Under EN 13304, grades are expressed as multiples of 5, so 115/15 sits within the standard’s prescribed classification matrix.
How does Oxidized Bitumen 115/15 differ from standard penetration-grade bitumen?
Penetration-grade bitumens such as 60/70 and 80/100 are produced by vacuum distillation and optimised for road paving. Oxidized Bitumen 115/15 undergoes an additional air-blowing stage that fundamentally changes its colloidal structure — raising asphaltene content, reducing plasticity index, and increasing Penetration Index (PI) above +2. The result is a gel-structured binder with far lower thermal susceptibility: it remains harder at high temperatures and is more dimensionally stable than penetration grades of equivalent measured stiffness. This makes it unsuitable for road paving but ideal for industrial, roofing, and waterproofing applications.
What climate conditions is Oxidized Bitumen 115/15 best suited for?
With a softening point of 110–120°C, this grade retains structural integrity at surface temperatures encountered in extreme hot climates — making it particularly suitable for roofing and pipe-coating projects in the Middle East, South Asia, North Africa, and sub-Saharan Africa. It performs reliably in temperate climates for most industrial applications as well.
What European standard governs this product?
The governing European framework is BS EN 13304:2009 — “Bitumen and bituminous binders: Framework for specification of oxidised bitumens” — published by the British Standards Institution and adopted identically across EU and EEA member states. Our product is manufactured and tested to comply with this standard in addition to ASTM requirements.
Can Oxidized Bitumen 115/15 be used as a bonding agent for SBS membranes?
Yes. SBS-modified bituminous damp-proof membranes can be cemented using blown bitumen in a casting process. Where used as an outer damp-proof course, a high-performance UV-protective layer must be applied over the assembly, as SBS membranes are sensitive to UV radiation.
Why Source from Gilsonite Co.?
- Direct supply from Iranian refineries — one of the world’s most cost-competitive production sources for oxidized bitumen
- Batch-certified to ASTM and BS EN 13304:2009
- Full TDS and MSDS documentation with every shipment
- Third-party independent inspection at loading port
- Export loading from Jebel Ali Port, Dubai (UAE) and Iskenderun Port (Turkey)
- FOB, CFR, and CIF pricing available for B2B buyers worldwide
Contact our export team to request a product datasheet, safety data sheet, or competitive quotation.
Technical References: Eurobitume — General Information on Bitumen Production and Applications (eurobitume.eu) | BS EN 13304:2009 / DIN EN 13304 — Framework for Specification of Oxidised Bitumens | IBEF — The Bitumen Industry: A Global Perspective (IS-230) | ACS Energy & Fuels — Relationships between Chemical Composition, Asphaltene Nanostructures, and Thermochemical Properties of Bitumen (2023) | ScienceDirect / Construction and Building Materials Vol. 438 (2024) | ASTM International — D36, D5, D113, D92, D6, D4, D70
