Bitumen PG 64-16 — Production, Specification & Applications
PG 64-16 is chosen when the upper temperature requirement is genuinely 64 degrees but the winter record does not justify a minus 22 degree floor.
Where PG 64-16 sits on the temperature scale
Performance grading ties the binder to the climate of the road rather than to a refinery output slate. The shaded band is the range PG 64-16 is certified to serve, a useful span of 80 degrees.
What distinguishes PG 64-16
Narrowing the span by six degrees removes the hardest part of the specification. The bending beam criteria move from minus 12 to minus 6 °C, which widens the range of crude slates that can comply and reduces the likelihood that modification is required.
What buyers should know
In practice this is a specification-discipline grade. Authorities that hold accurate pavement temperature records and are willing to grade precisely will specify PG 64-16 where a less rigorous process would default to PG 64-22. The saving is real but modest, and it disappears entirely if the winter data is wrong.
How Bitumen PG 64-16 is produced
Understanding the refining route explains why some grades are readily available and others are not, and why two binders that look similar on a datasheet can behave differently in service.
From crude oil to vacuum residue
The refining route is identical to that for any straight-run paving binder: atmospheric distillation, then vacuum distillation of the long residue, with the cut point of the vacuum column setting the consistency of the residue that remains. What differs between grades in the 64-series is not the process but how tightly the resulting binder has to satisfy the cold end of the envelope.
Reaching the PG 64-16 envelope
Because the bending beam requirement for PG 64-16 falls at minus 6 °C rather than minus 12 °C, a wider range of crude slates qualifies. Waxy and paraffinic crudes that would fail the m-value criterion at minus 12 °C frequently pass at minus 6 °C, which brings additional refineries into the supply pool. That is the practical meaning of the six-degree narrowing: it is a supply-side widening rather than a quality reduction.
Production control
Production control for this grade concentrates on the dynamic shear result at 64 °C, which is the binding constraint. In-process samples are taken from the blending tank and run on the dynamic shear rheometer before the parcel is released, since the upper grade is what will be checked first on receipt.
Derived test temperatures you can check
The two intermediate temperatures on a PG 64-16 certificate follow arithmetically from the grade, so a buyer can verify the document without reference to any other source.
| Test | Derivation | Result for PG 64-16 |
|---|---|---|
| PAV dynamic shear (fatigue) | (64 + −16) ÷ 2 + 4 | 28 °C |
| Bending beam (stiffness, m-value) | −16 + 10 | −6 °C |
Bitumen PG 64-16 specification
| Property | Test method | Requirement |
|---|---|---|
| Average 7-day max pavement design temperature | AASHTO M323 | 64 °C |
| Minimum pavement design temperature | AASHTO M323 | −16 °C |
| Original binder | ||
| Flash point, Cleveland open cup | AASHTO T48 | min 230 °C |
| Rotational viscosity @ 135 °C | AASHTO T316 | max 3 Pa·s |
| Dynamic shear G*/sinδ @ 64 °C | AASHTO T315 | min 1.00 kPa |
| After RTFOT (short-term ageing) | ||
| Change of mass | AASHTO T240 | max 1.00 % |
| Dynamic shear G*/sinδ @ 64 °C | AASHTO T315 | min 2.20 kPa |
| After PAV @ 100 °C (long-term ageing) | ||
| Dynamic shear G*·sinδ @ 28 °C | AASHTO T315 | max 5000 kPa |
| Creep stiffness S @ −6 °C | AASHTO T313 | max 300 MPa |
| m-value @ −6 °C | AASHTO T313 | min 0.300 |
The full PG 64-16 specification is tested to AASHTO M320 and reported on the certificate of analysis for every parcel. Nearest indicative equivalents: penetration grade 60/70, viscosity grade VG-30. These are reference points for discussion, not substitutions. A certificate of analysis accompanies every shipment; third-party inspection by SGS, Intertek or an equivalent surveyor can be arranged at the buyer instruction and account.
Where Bitumen PG 64-16 is used
Continental highways
Routes in interiors with hot summers and cold but not severe winters, where the seasonal swing is wide but bounded and the winter record is well documented.
Airport taxiways
Movement areas where rutting under slow aircraft loading and winter cracking both need control, and where the winter record does not justify a minus 22 floor.
Cold-region structural overlays
Overlays on ageing pavement in continental climates where the existing layers already carry thermal movement and the overlay must accommodate it.
Bridge deck surfacing
Decks exposed to air on both faces, which reach lower minima than adjacent embankment pavement and therefore need a wider span than the surrounding road.
Highland arterial roads
Elevated alignments with hot days and cold nights, where the diurnal range is as significant as the seasonal one.
Industrial access routes
Plant and terminal roads in continental climates carrying sustained heavy traffic through a wide annual temperature range.
Mix design and handling temperatures
Mixing and compaction temperatures are set from the binder viscosity–temperature relationship rather than from the grade designation alone. The ranges below are typical starting points for PG 64-16 and should be confirmed against the rotational viscosity figure on the delivered certificate.
| Operation | Typical range for PG 64-16 | Control note |
|---|---|---|
| Bulk storage | 150–170 °C | Circulate to prevent local overheating at the heating coils |
| Pumping and transfer | 150–170 °C | Confirm line tracing is operating before transfer begins |
| Hot mix asphalt mixing | 150–165 °C | Target viscosity approximately 0.17 Pa·s |
| Compaction | 130–150 °C | Target viscosity approximately 0.28 Pa·s; 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.
What happens when PG 64-16 is mis-specified
The characteristic failure with PG 64-16 is a winter data error rather than a summer one. Where the recorded minimum was interpolated from a distant station, or taken at 50 per cent reliability when the authority intended 98 per cent, the pavement can see minus 20 °C on an exceptional night and crack transversely. The cracking is not progressive in the way rutting is; it appears after a single severe event and then persists.
Available packing for PG 64-16
| 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 PG 64-16 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 specific to PG 64-16
How much cheaper is PG 64-16 than PG 64-22?
The difference is normally small and varies with the refinery. It is worth requesting both prices before deciding, because in some months the higher production volume of PG 64-22 makes it the cheaper of the two despite the tighter specification.
Our winter record shows minus 17 degrees once in fifteen years. Is PG 64-16 acceptable?
That is a reliability question rather than a yes or no. At 50 per cent reliability PG 64-16 is defensible; at 98 per cent it is not, because the specification is intended to cover the extreme year rather than the typical one. Most trunk-route authorities specify 98 per cent.
Why is the bending beam run at minus 6 degrees for this grade?
AASHTO M320 tests at the low design temperature plus 10 °C, relying on time-temperature superposition so that a 60-second test at minus 6 °C predicts the two-hour response at minus 16 °C. A certificate reporting the bending beam at minus 16 °C for PG 64-16 has not followed the standard.
Does the narrower span mean more refineries can supply it?
Yes, and that is the main practical consequence. Paraffinic and waxy crude slates that fail the m-value criterion at minus 12 °C frequently pass at minus 6 °C, which enlarges the supply pool for PG 64-16 relative to PG 64-22 even though the latter is produced in greater total volume.
Can PG 64-16 be substituted where PG 64-22 was specified?
Not without the specifying engineer’s approval. The upper grades match, but the cold-temperature certification does not. If the tender was written around a minus 22 design temperature, a PG 64-16 binder is outside specification regardless of how well it performs in summer.
The performance grade range
Intermediate temperatures below are derived from each grade, not selected by the supplier.
| Grade | Upper | Lower | Span | PAV DSR | Bending beam | Pen equiv. |
|---|---|---|---|---|---|---|
| PG 70-10 | 70 °C | −10 °C | 80 °C | 34 °C | 0 °C | 40/50 |
| PG 64-22 | 64 °C | −22 °C | 86 °C | 25 °C | −12 °C | 60/70 |
| PG 64-16 | 64 °C | −16 °C | 80 °C | 28 °C | −6 °C | 60/70 |
| PG 64-10 | 64 °C | −10 °C | 74 °C | 31 °C | 0 °C | 60/70 |
| PG 58-22 | 58 °C | −22 °C | 80 °C | 22 °C | −12 °C | 85/100 |
| PG 58-16 | 58 °C | −16 °C | 74 °C | 25 °C | −6 °C | 85/100 |
| PG 58-10 | 58 °C | −10 °C | 68 °C | 28 °C | 0 °C | 85/100 |
| PG 52-10 | 52 °C | −10 °C | 62 °C | 25 °C | 0 °C | 120/150 |
Speak to a Bitumen PG 64-16 supplier
Send quantity in metric tonnes, required packing, destination port and preferred Incoterm. Offers are normally returned within one working day.