Bitumen Types
Types of Bitumen – Penetration Grades
Production of different grades of penetration bitumen is achieved by adjusting the air-blowing rate, taking into account feedstock parameters such as temperature and viscosity. Lower air-blowing rates yield bitumen with higher penetration values.
Performance Grade Bitumen (PG Bitumen)
Production of 13 unmodified PG-grade bitumens (without additives) based on Superpave classification system, out of 33 general grades, and 10 grades from 13 regional climate-specific PG grades available in the country.
Cutback Bitumen (Back Cut)
Production by blending penetration-grade bitumen (e.g. 60/70) at 180–190°C with petroleum-based solvents such as white oil, diesel, or gasoline at 160–170°C, using either stirred tanks or continuous in-line blending, followed by storage at 60°C. The blend ratio is adjusted based on the desired cutback grade. Application: Tack coats between asphalt layers or prime coats before asphalt laying.
Bitumen Emulsion (Green Bitumen)
Manufactured by blending an aqueous phase (water, acid, emulsifier, salt) at 40°C with hot bitumen (135–145°C) using a high-shear colloid mill. Stored at 70°C.Applications: Base bonding, rapid surface sealing, cold mix asphalt, and mulching. Preferred alternative to cutbacks for environmental and cost benefits.
Polymer Modified Bitumen (PMB)
Designed to withstand high thermal and mechanical stresses. PMBs exhibit superior elasticity, resistance to cracking, deformation (rutting), and fatigue. Suitable for demanding applications. Covers extended PG ranges, e.g., PG 76-22, PG 82-10.
Oxidized / Blown Bitumen (Special Grades)
Produced via air-blowing under controlled conditions to reduce penetration and increase softening point. Example: Grade 10/90 (penetration: 10, softening point: 90°C). Produced in batch reactors due to extended residence time.Used in industrial insulation and roofing. Low-volume specialty product.
Natural Bitumen (Gilsonite / Mineral Bitumen)
Gilsonite is a naturally occurring asphaltite found in regions like Kermanshah (Gilan-e-Gharb). It is used in asphalt modification, printing inks, paints, drilling fluids, and adhesives. For asphalt, low-ash grades are preferred.Widely used in China for ink production.