Bitumen 20/30 — Specification, Production & Applications
Bitumen 20/30 is a hard penetration grade specified where deformation resistance under sustained heat and heavy loading outweighs every other consideration.
Where Bitumen 20/30 sits among the penetration grades
Penetration is measured as the depth in tenths of a millimetre that a standard needle penetrates the binder in five seconds at 25 °C under a 100 g load, to ASTM D5. A lower number means a harder binder. The scale above runs from hard on the left to very soft on the right.
What defines Bitumen 20/30
With a penetration of 20 to 30 tenths of a millimetre at 25 °C and a softening point held between 55 and 63 °C, this is the stiffest paving-related penetration grade in ordinary supply. The narrow softening point window is unusual: most grades quote only a minimum, and specifying both ends signals that the binder is intended for a mix design with tight rheological tolerances.
The values that matter
Its stiffness is also its constraint. A binder this hard has limited capacity to relax thermal stress, so it is inappropriate for climates with meaningful winters. Where 20/30 is used in a cold region, transverse cracking is the predictable outcome. It is a hot-climate, high-modulus material.
How Bitumen 20/30 is produced
Refining route
Bitumen 20/30 is produced from a deep vacuum cut. After atmospheric distillation strips the light fractions, the long residue is charged to a vacuum column and the remaining heavy gas oils are removed under reduced pressure. Taking the cut deeper leaves fewer of the oily maltene fractions in the residue, which is what raises stiffness and softening point together.
Blend and release control
Not every crude slate reaches 20/30 straight-run at an acceptable yield. Asphaltic and naphthenic crudes with high native asphaltene content get there most readily. Where the slate cannot, the grade is reached by blending a very hard residue with a softer stream until both the penetration window and the 55 to 63 °C softening point band are satisfied, then re-testing the blend.
Bitumen 20/30 specification
| Property | Test method | Unit | Requirement |
|---|---|---|---|
| Density @ 25 °C | ASTM D70 | g/cm³ | 1.01–1.06 |
| Penetration @ 25 °C, 100 g, 5 s | ASTM D5 | ×0.1 mm | 20–30 |
| Softening point, ring and ball | ASTM D36 | °C | 55–63 |
| Ductility @ 25 °C | ASTM D113 | cm | min 100 |
| Loss on heating | ASTM D6 | wt % | max 0.2 |
| Retained penetration after heating | EN 1426 | % | min 20 |
| Solubility in trichloroethylene | ASTM D2042 | wt % | min 99 |
| Flash point, Cleveland open cup | ASTM D92 | °C | min 230 |
| Spot test | AASHTO T102 | — | negative |
A certificate of analysis accompanies every shipment. Independent inspection by SGS, Intertek or an equivalent surveyor can be arranged at the buyer instruction and account.
Where Bitumen 20/30 is used
High-modulus asphalt
Base and binder courses in high-modulus mixes designed to carry very heavy traffic with minimal rutting.
Industrial and port pavements
Container yards, weighbridge approaches and hardstanding where slow or static loading dominates.
Mastic asphalt
Hand-laid mastic for bridge decks, roofing and waterproofing where flow resistance at temperature is essential.
Hot climate trunk roads
Highways in desert and tropical regions with no meaningful winter minimum.
Airport aprons
Aircraft stands where sustained static loading over long dwell times drives deformation.
Bituminous paints and compounds
Industrial formulations requiring a hard base binder.
Handling and application temperatures
Working temperatures follow the binder viscosity rather than the grade designation alone. The ranges below are typical starting points for Bitumen 20/30 and should be confirmed against the mix design.
| Operation | Typical range | Control note |
|---|---|---|
| Bulk storage | 160–180 °C | Circulate to avoid local overheating at the coils |
| Pumping and transfer | 160–180 °C | Confirm line tracing before transfer begins |
| Hot mix asphalt mixing | 165–180 °C | Per mix design, not per binder alone |
| Compaction | 145–165 °C | Cease rolling below the lower figure |
| Maximum sustained heating | below 180 °C | Above this, oxidative hardening accelerates sharply |
Drummed material should be reheated in a controlled oven or hot room rather than by direct flame. Localised overheating hardens the binder at the drum wall and can take a compliant parcel out of specification before it reaches the mixer.
Available packing for Bitumen 20/30
| Packing | Net weight | Loading per 20 ft FCL | Typical use |
|---|---|---|---|
| New steel drum | 150 / 180 / 185 / 200 kg | 110 drums, 20.35 MT at 185 kg | Smaller parcels, sites without bulk storage |
| Jumbo bag | 1 MT | 20 MT | Lower packing cost, requires melting facility |
| Flexitank / bitutainer | 20–22 MT | 1 unit | Bulk economics without a bulk vessel |
| Bulk vessel | by parcel | heated tanker | Terminal to terminal, largest volumes |
As a Bitumen 20/30 supplier Bitumen Asphaltive ships on CFR, CIF and FOB terms with commercial invoice, packing list, bill of lading, certificate of origin and certificate of analysis.
Questions about Bitumen 20/30
Why does 20/30 quote both a minimum and a maximum softening point?
Most penetration grades quote a minimum only, because the concern is that the binder is not too soft. Specifying an upper bound as well, here 63 °C, constrains how hard the binder may be. That matters for a grade this stiff because an over-hard binder becomes brittle and loses the little stress-relaxation capacity it has.
Can bitumen 20/30 be used in a temperate climate?
It is a poor choice. The binder has limited ability to relax tensile stress as the pavement contracts, so a winter minimum of even a few degrees below zero raises the risk of regularly spaced transverse cracking. Where both summer stiffness and winter flexibility are needed, a performance grade with an explicit low-temperature certification is the safer specification.
How does 20/30 differ from an oxidised grade of similar hardness?
An oxidised bitumen reaches its high softening point through partial air blowing, which changes the binder chemistry and degrades its low-temperature behaviour. Bitumen 20/30 reaches its hardness through a deeper vacuum cut on straight-run material. The two behave differently under traffic and should not be substituted for one another.
What flash point should the certificate show?
A minimum of 230 °C by ASTM D92, Cleveland open cup. A lower figure suggests contamination with a lighter fraction and should be queried, since it affects both safety margin during heating and the binder behaviour in the mixer.
The penetration grade range
Penetration windows overlap between adjacent grades, so a single parcel can sometimes satisfy two specifications. Ageing limits and softening point are what separate them.
| Grade | Penetration @ 25 °C | Character |
|---|---|---|
| Bitumen 20/30 | 20–30 × 0.1 mm | Hard |
| Bitumen 30/40 | 30–40 × 0.1 mm | Hard |
| Bitumen 40/50 | 40–50 × 0.1 mm | Medium hard |
| Bitumen 50/70 | 50–70 × 0.1 mm | Medium hard |
| Bitumen 60/70 | 60–70 × 0.1 mm | Medium hard |
| Bitumen 70/100 | 70–100 × 0.1 mm | Medium soft |
| Bitumen 80/100 | 80–100 × 0.1 mm | Medium soft |
| Bitumen 85/100 | 85–100 × 0.1 mm | Medium soft |
| Bitumen 120/150 | 120–150 × 0.1 mm | Soft |
| Bitumen 200/300 | 200–300 × 0.1 mm | Very soft |
Speak to a Bitumen 20/30 supplier
Send quantity in metric tonnes, required packing, destination port and preferred Incoterm. Offers are normally returned within one working day.