Types of Bitumen
Penetration Grade
Straight-run paving bitumen classified by needle penetration at 25 °C — the workhorse grades 40/50, 60/70, 80/100 and 120/150.
Penetration grade bitumen is the standard binder for hot mix asphalt across most of the world. It is produced by vacuum distillation with no chemical modification, which keeps the natural balance of the residue intact and gives a predictable, well-understood material.
The grade name is the penetration range itself. A 60/70 binder allows a standard needle to sink between 6.0 and 7.0 millimetres under a 100 g load held for five seconds at 25 °C. Lower numbers mean a harder binder.
Choosing the right grade
Grade selection is a balance between two failure modes. A binder that is too soft for the climate will rut and bleed in summer; one that is too hard will crack in winter and under fatigue loading. Mean annual air temperature, peak pavement temperature and traffic volume all feed into the decision.
As a rule of thumb, the hotter the climate and the heavier the axle loading, the harder the grade. Gulf and North African projects commonly specify 40/50 or 60/70; temperate European work tends towards 70/100 or 100/150.
Grades Addam supplies
- Bitumen 40/50 — hard grade for very hot climates and heavily trafficked pavements
- Bitumen 60/70 — the most widely traded grade, suited to hot and warm climates
- Bitumen 80/100 — medium grade for moderate climates and lighter traffic
- Bitumen 85/100 — close equivalent to 80/100, specified in several national standards
- Bitumen 120/150 — soft grade for cold regions and cold-mix applications
- Bitumen 160/220 — very soft grade for low-temperature and specialist use
Typical applications
- Hot mix asphalt for highways, urban roads and airfield pavements
- Asphalt concrete base, binder and wearing courses
- Surface dressing and chip sealing
- Feedstock for cutback, emulsion and polymer modified binders
- Industrial flooring and heavy-duty hardstanding
Typical specification
| Penetration @ 25 °C, 100 g, 5 s | ASTM D5 — to grade |
|---|---|
| Softening point (ring & ball) | ASTM D36 — 46 to 56 °C typical for 60/70 |
| Ductility @ 25 °C | ASTM D113 — 100 cm minimum |
| Flash point (Cleveland open cup) | ASTM D92 — 250 °C minimum |
| Solubility in trichloroethylene | ASTM D2042 — 99% minimum |
| Loss on heating | ASTM D6 — 0.2% maximum |
| Specific gravity @ 25 °C | ASTM D70 — 1.01 to 1.06 |
Values are indicative and given for guidance. Contract specification is agreed in writing and certified per batch on the certificate of analysis issued with each shipment.
