Penetration Grade Bitumen is a refined hydrocarbon binder derived from crude oil through fractional distillation and further air blowing or vacuum processing. It is classified based on its penetration value, which indicates the relative hardness or softness of the bitumen at 25°C, measured using standardized needle penetration tests (ASTM D5 / EN 1426).
The penetration value reflects rheological behavior, workability during mixing, and resistance to deformation under traffic loads. Lower penetration values indicate harder bitumen, while higher values indicate softer grades.
Common Penetration Grades
30/40 – Very hard, high load resistance
40/50 – Heavy traffic and high-temperature regions
60/70 – Most widely used general paving grade
80/100 – Moderate climates and low traffic roads
100/120 – Cold regions and light-duty applications
Manufacturing & Refining Process
Crude Oil Distillation
Crude oil is processed in vacuum distillation units to separate lighter fractions such as gasoline, diesel, and fuel oil.
Residue Processing
The heavy vacuum residue is further refined to achieve desired penetration, viscosity, and temperature performance.
Quality Adjustment
Controlled blending and air oxidation ensure stable penetration range, improved aging resistance, and high purity.
Final Testing & Certification
Each batch is tested to comply with ASTM, EN, IS (IS 73:2013), or project-specific specifications.
Key Characteristics
High Viscosity & Rheological Stability
Provides excellent load distribution under heavy traffic and ensures proper aggregate coating during asphalt mixing.
Superior Water Resistance
Hydrophobic nature prevents moisture damage and stripping, enhancing pavement durability in monsoon regions.
Thermal Performance
Maintains flexibility at service temperatures while resisting cracking at low temperatures and rutting at high temperatures.
Strong Aggregate Adhesion
Forms durable bonds with acidic and basic aggregates, improving fatigue resistance.
Aging & Oxidation Resistance
Low loss on heating ensures long-term elasticity and penetration stability.
Consistency & Purity
High solubility (>99%) confirms absence of impurities and ensures uniform paving performance.
Typical Mechanical & Physical Properties
| Property | Typical Range |
|---|---|
| Penetration @ 25°C | 30–40 to 100–120 (grade dependent) |
| Softening Point (°C) | 45 – 55 |
| Ductility @ 25°C | >100 cm |
| Specific Gravity | 1.00 – 1.05 |
| Flash Point (°C) | ≥250 |
| Fire Point (°C) | ≥300 |
| Viscosity @ 135°C | Grade dependent |
| Loss on Heating | <1% |
| Solubility | >99% |
Climate & Traffic Suitability
| Grade | Recommended Use |
|---|---|
| 30/40 | High temperatures, heavy traffic, expressways |
| 40/50 | Warm climates, industrial roads |
| 60/70 | Moderate climates, highways, urban roads |
| 80/100 | Cooler regions, secondary roads |
| 100/120 | Cold climates, low-traffic applications |
Available Supply Forms & Logistics
Steel drums (180–200 kg)
Bulk tanker supply for large projects
Poly bags / jumbo bags for easy handling
Bitutainers for export shipments
Direct bulk storage supply to project sites
Storage & Handling Guidelines
Recommended storage temperature: 120°C – 150°C
Avoid overheating to prevent oxidation and hardening
Use insulated tanks for extended storage
Applications of Penetration Grade Bitumen
Road & Highway Construction
Hot Mix Asphalt (HMA), Dense Bituminous Macadam (DBM), Bituminous Concrete (BC), surface dressing, premix carpets, flexible pavement layers
Industrial Applications
Roofing membranes, bituminous paints, expansion joint fillers, vibration-damping compounds
Waterproofing & Protection
Foundation damp proofing, basement waterproofing, corrosion protection for concrete and steel
Specialized Uses
Pipeline coating, crack sealing materials, industrial adhesive formulations
Advantages Over Other Bitumen Types
Proven performance in conventional road construction
Easier handling than polymer-modified bitumen
Cost-effective for large infrastructure projects
Wide availability in global markets