Bitumen PG 58-22 — Production, Specification & Applications
PG 58-22 is a cold-climate grade in which the low-temperature criteria, not the high-temperature ones, drive production.
Where PG 58-22 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 58-22 is certified to serve, a useful span of 80 degrees.
What distinguishes PG 58-22
Meeting a creep stiffness of 300 MPa or less and an m-value of 0.300 or more at minus 12 °C after pressure ageing constrains crude selection considerably, while the 58 °C upper requirement is comparatively undemanding.
What buyers should know
This inversion has a commercial consequence that surprises buyers used to hot-climate grades: the softer-sounding grade is often the harder one to source. Refineries oriented toward tropical export markets may not run a binder that satisfies a minus 22 degree floor at all, and lead times reflect that.
How Bitumen PG 58-22 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 process route is conventional — atmospheric distillation followed by vacuum distillation — but the selection criteria are inverted relative to hot-climate grades. Here the vacuum cut is taken shallower, leaving more of the maltene fraction in the residue, because it is the oily and resinous components that give the binder its ability to relax stress at low temperature.
Reaching the PG 58-22 envelope
Crude selection matters more for this grade than for any other in the series. Waxy and highly paraffinic crudes produce residues that crystallise at low temperature and fail the m-value criterion at minus 12 °C even when creep stiffness is acceptable. Naphthenic crudes with low wax content are strongly preferred. Where the available slate cannot deliver the cold-temperature performance, styrene-butadiene-styrene modification is used, not to raise the upper grade but to improve low-temperature relaxation.
Production control
Quality control is therefore focused on the bending beam rheometer. Beams are moulded from the pressure ageing vessel residue, conditioned at minus 12 °C and loaded for 240 seconds, with creep stiffness and the m-value both calculated at the 60-second loading time. A parcel that meets stiffness but misses the m-value target is rejected, and this is the more frequent of the two failure modes.
Derived test temperatures you can check
The two intermediate temperatures on a PG 58-22 certificate follow arithmetically from the grade, so a buyer can verify the document without reference to any other source.
| Test | Derivation | Result for PG 58-22 |
|---|---|---|
| PAV dynamic shear (fatigue) | (58 + −22) ÷ 2 + 4 | 22 °C |
| Bending beam (stiffness, m-value) | −22 + 10 | −12 °C |
Bitumen PG 58-22 specification
| Property | Test method | Requirement |
|---|---|---|
| Average 7-day max pavement design temperature | AASHTO M323 | 58 °C |
| Minimum pavement design temperature | AASHTO M323 | −22 °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 @ 58 °C | AASHTO T315 | min 1.00 kPa |
| After RTFOT (short-term ageing) | ||
| Change of mass | AASHTO T240 | max 1.00 % |
| Dynamic shear G*/sinδ @ 58 °C | AASHTO T315 | min 2.20 kPa |
| After PAV @ 100 °C (long-term ageing) | ||
| Dynamic shear G*·sinδ @ 22 °C | AASHTO T315 | max 5000 kPa |
| Creep stiffness S @ −12 °C | AASHTO T313 | max 300 MPa |
| m-value @ −12 °C | AASHTO T313 | min 0.300 |
The full PG 58-22 specification is tested to AASHTO M320 and reported on the certificate of analysis for every parcel. Nearest indicative equivalents: penetration grade 85/100, viscosity grade VG-20. 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 58-22 is used
Severe winter highways
Trunk routes with sustained sub-zero periods where transverse thermal cracking is the recorded dominant failure mode in maintenance records.
Freeze-thaw exposed pavements
Surfaces subject to repeated freezing and thawing, which combines thermal movement with moisture damage and makes crack resistance the governing property.
Northern arterial and trunk roads
Regional routes where winter cracking accounts for the majority of the maintenance budget and rutting is a secondary concern.
Cold-climate runways
Airport pavements in northern territories where crack-induced debris is a flight safety consideration rather than a maintenance one.
Mountain pass alignments
High-altitude routes with severe winter minima, moderate summer maxima and very large diurnal swings.
Continental interior networks
Inland road systems with an extreme annual temperature range and modest peak surface heat.
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 58-22 and should be confirmed against the rotational viscosity figure on the delivered certificate.
| Operation | Typical range for PG 58-22 | Control note |
|---|---|---|
| Bulk storage | 145–165 °C | Circulate to prevent local overheating at the heating coils |
| Pumping and transfer | 145–165 °C | Confirm line tracing is operating before transfer begins |
| Hot mix asphalt mixing | 145–160 °C | Target viscosity approximately 0.17 Pa·s |
| Compaction | 125–145 °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 58-22 is mis-specified
If PG 58-22 is used where the summer requirement was actually PG 64 or higher, rutting develops quickly because the binder was never certified above 58 °C. This mis-specification often arises when a project takes the grade from a neighbouring cold-climate scheme without re-checking the summer maximum, or when the traffic adjustment for slow or standing traffic is omitted.
Available packing for PG 58-22
| 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 58-22 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 58-22
Why is a soft grade like PG 58-22 sometimes harder to obtain than PG 64-22?
Because the constraint is the low-temperature end, not the high. A refinery can raise stiffness readily; producing a binder that stays relaxed at minus 12 °C on the bending beam after pressure ageing depends on the crude slate and the vacuum cut, and not every producer can do it from the crude they run.
Is the 22 degree PAV dynamic shear temperature an error?
No. It is the arithmetic result of the grade: 58 plus minus 22, divided by two, plus four, gives 22 °C. Every PG 58-22 certificate should report the fatigue dynamic shear at that temperature.
We need PG 58-22 but also have standing traffic. What should we specify?
Traffic adjustment raises the upper grade by two levels for standing traffic, giving PG 70-22. That is a 92-degree span and a demanding binder. Confirm availability and price before issuing the tender, as it will normally require polymer modification.
Why do waxy crudes cause problems for this grade?
Wax crystallises as temperature falls, which stiffens the binder and slows its ability to relax stress. The bending beam m-value is a direct measure of that relaxation rate, and waxy residues frequently fail it at minus 12 °C even when the creep stiffness result is comfortably within limit.
Can modification be used to reach the low-temperature requirement?
Yes. Elastomeric modification is normally associated with raising the upper grade, but it also improves low-temperature relaxation and is used for that purpose where the base crude cannot deliver the m-value. Confirm whether the offered product is modified, since it affects site storage arrangements.
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 58-22 supplier
Send quantity in metric tonnes, required packing, destination port and preferred Incoterm. Offers are normally returned within one working day.