Bitumen, also known as asphalt cement, is a viscous, black, semi-solid hydrocarbon material obtained as the heaviest fraction remaining after atmospheric and vacuum distillation of crude oil. Chemically, it is a complex blend of aromatics, resins, saturates, and asphaltenes, and it stands among the most strategic derivatives of the oil and petrochemical industry, playing a foundational role in road construction, waterproofing, and industrial insulation worldwide.
Holding one of the world’s largest proven crude oil reserves and operating a network of advanced refineries, Iran ranks among the leading bitumen producers and exporters in the Middle East. The high asphaltene content and favorable thermal stability of Iranian heavy crude provide an excellent base for producing bitumen grades that meet consistent demand across South Asian, African, and Persian Gulf markets.
Main Types and Grades
Bitumen is classified into several categories depending on the production method and intended application:
Penetration Grade Bitumen (40/50, 60/70, 85/100) — the most widely used type in hot-mix asphalt for road construction, with penetration depth measured under ASTM D5 at 25°C under a 100g load.
Viscosity Grade Bitumen (VG10, VG20, VG30, VG40) — classified by kinematic viscosity at 135°C, commonly specified for heavy-traffic roads and hot-climate infrastructure projects.
Oxidized (Blown) Bitumen (85/25, 90/15, 95/25) — produced by passing air through base bitumen at elevated temperatures, resulting in a higher softening point suited to waterproofing membranes, roofing felt, and roof coating applications.
Bitumen Emulsion — cationic (CRS, CMS, CSS) or anionic types, produced by dispersing bitumen particles in water with an emulsifying agent, applied at ambient temperature without the need for heating.
Cutback Bitumen (MC, RC grades) — produced by diluting bitumen with petroleum solvents, mainly used for priming and surface sealing.
Production Process and Technical Properties
The production of bitumen begins with atmospheric distillation of crude oil and continues through vacuum distillation, where lighter fractions are separated and the heavy residue is recovered as straight-run bitumen. Final quality is controlled and verified through parameters such as penetration depth, softening point (Ring & Ball method), flash point (typically above 250°C), specific gravity (approximately 1.00–1.06 g/cm³), and low-temperature ductility.
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Industrial and Construction Applications
As one of the most widely used materials in the construction industry, bitumen serves the following applications:
Road surfacing and base layers, airport runways, hot- and cold-mix asphalt
Production of roofing felt, waterproofing membranes, and building damp-proofing systems
Anti-corrosion pipe coating for oil and gas pipelines
Manufacturing of bituminous paints, industrial adhesives, and sealants for marine and port structures
Drilling fluid additives for select oil and gas well operations
Iran’s export-grade bitumen is typically produced and packed in accordance with international standards including ASTM D946, EN 12591, IS 73:2013, and BS 3690, and shipped in new 180kg steel drums, in bulk, or occasionally in jumbo bags. Backed by a reliable sourcing network across domestic refineries, Coolak supplies a full range of bitumen grades with complete quality documentation (COA) and flexible delivery terms (FOB Bandar Abbas, Bandar Imam, and Chabahar) for international buyers.
