Iranian bitumen: a practical international buyer’s guide
From vacuum bottom to shipment: how to specify the right binder, read the COA and prevent grade, packaging and documentation disputes.
20 min read · Technical review · 9 September 2026Download the complete Persian publication
Petroleum bitumen is a viscoelastic hydrocarbon binder, mainly produced from heavy refinery residue. Bitumen is the binder; asphalt mix combines that binder with aggregate and filler.
A grade name is only a starting point. A professional order defines the standard and edition, acceptance limits, test methods, batch identification, sampling, inspection and dispute laboratory.
Three grading systems that must not be treated as equivalents
Indicative orientation only. The governing standard, project specification and batch COA control the sale.
From crude oil to controlled batch
Feed quality and refinery severity influence the residue. Vacuum bottom can become straight-run bitumen when it meets the specification, or be air-rectified, blended or modified under controlled conditions.
- Crude selection and atmospheric distillation
- Vacuum distillation and vacuum-bottom recovery
- Straight-run release, controlled air rectification or modification
- Heated storage, circulation and homogenisation
- Representative sampling, testing and batch release
Main commercial product families
Penetration grades
60/70 and 80/100 for roadwork where the nominated specification accepts them.
Viscosity grades
VG10, VG20, VG30 and VG40 for IS 73-based tenders and projects.
Performance grades
PG binders selected for pavement temperature and traffic loading.
Oxidized bitumen
Roofing, waterproofing, pipe coating, sealants and industrial compounds.
Emulsion / cutback
Surface treatments, tack or prime applications subject to project and environmental rules.
Polymer-modified binder
High-stress pavements after compatibility, storage-stability and performance testing.
Tests a serious buyer should see on the batch COA
Penetration at 25°C
Relative consistency; not a complete performance verdict.
Ring-and-ball softening point
Temperature at defined softening—not a true melting point.
Ductility
Elongation under the specified test conditions.
Flash point
Handling safety and screening for excessive volatiles.
Solubility
Screens non-bituminous material under the specified solvent method.
Absolute / kinematic viscosity
Essential when a viscosity grade is claimed.
Short-term ageing
Assesses change after simulated mixing and placement.
PG rheology
Workability and high-, intermediate- and low-temperature behaviour.
Choose by project—not by the darkest colour
- Confirm the buyer’s standard, edition and every acceptance limit.
- Use climate, pavement temperature, traffic speed and axle loading—not a simple grade-name conversion.
- Do not sell 60/70 as VG30 unless one batch passes the complete requirements of both systems.
- For modified binders, verify storage stability, recovery/MSCR where specified and properties after ageing.
Packaging, shipment and documents
Compare landed cost—not price per tonne alone. Net weight, usable payload, heating, leakage, melting, waste and destination equipment can change the best option.
- Bulk tanker or bitumen vessel for suitable high-volume routes
- New steel drums for flexible containerised distribution
- Jumbo bags / approved meltable bags only with compatible filling and destination handling
- Commercial invoice, packing list, batch COA, TDS, SDS and certificate of origin
- Transport document, weight certificate and independent inspection when contracted
- Incoterms® 2020 rule plus the exact named place or port
Red flags before payment
- Generic COA without batch, sampling date, method or laboratory
- VG30 claim supported only by penetration and softening point
- Producer, origin or loading-point names that conflict across documents
- Unusual solvent odour, water, foaming, solids or non-homogeneity
- Brand claims without a verifiable document and loading chain
- A fixed heating temperature copied across every grade instead of the supplier SDS/TDS
Educational procurement guidance. It is not a batch specification, engineering design or product warranty. Always use the licensed current standard, supplier TDS/SDS, batch-specific COA and contract.
Frequently asked questions
Is 60/70 the same as VG30?
No. They use different grading systems. One material may satisfy both, but only a complete set of tests can demonstrate that.
Is harder bitumen always better?
No. Excessive hardness can increase cracking risk. Selection depends on climate, pavement structure, traffic and the project specification.
Can quality be judged from appearance?
No. Colour, gloss and stringiness are only observations; conformity needs traceable sampling and standard tests.
Drums, bags or bulk?
Choose from total delivered cost and destination capability, including payload, heating, leakage, waste and unloading.
Primary references
ASTM D946/D946M — penetration-graded asphalt binderASTM D3381/D3381M — viscosity-graded asphalt binderASTM D6373 — performance-graded asphalt binderBIS IS 73:2013 — paving bitumen product manualFHWA — LTPPBind Online User GuideDownload the complete Persian publicationBuild the RFQ around evidence
Send the grade, governing standard, quantity, application, destination, packaging, delivery window and inspection requirement.
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