Low Temperature Bitumen
Last updated: 2026-10-08
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Low Temperature Bitumen
Low temperature bitumen refers to penetration-grade or polymer-modified grades engineered to remain workable and stable when ambient or mix temperatures drop below 0 °C. Standard grades such as 60/70 and 80/100 typically become brittle below +5 °C, while dedicated low-temperature grades maintain acceptable penetration (typically 40–60 dmm at 25 °C) and a Fraass breaking point of −15 °C or lower. In practice, formulators select these grades when paving, roofing, or waterproofing must continue in a −5 °C to +10 °C window without cracking, and they usually carry a price premium of 3–8% over standard penetration grades.
What Is Low Temperature Bitumen?
Low temperature bitumen is a bituminous binder whose rheological properties are adjusted so it performs below the temperatures at which conventional penetration grades turn brittle. It is defined less by origin and more by a set of test outcomes measured at low thermal stress.
Key defining characteristics:
- Fraass breaking point: −15 °C or lower (standard 60/70 typically breaks around −8 °C to −10 °C).
- Penetration at 25 °C: usually 40–60 dmm, sometimes 20–40 dmm for very cold climates.
- Softening point: 45–55 °C — lower than standard grades to preserve flexibility.
- Ductility at 25 °C: typically >100 cm, indicating the binder can stretch without fracturing.
- Dynamic viscosity at 60 °C: commonly 120–250 Pa·s.
The purpose of these adjustments is to widen the plastic range — the gap between the point where the binder becomes too soft and the point where it fractures. A wider plastic range means fewer thermal cracks when pavement or membrane surfaces cool rapidly overnight.
Two technology routes dominate:
1. Soft penetration grades — e.g. 200/300 or 100/150 — used where cold flexibility matters more than rutting resistance.
2. Polymer modification — adding 2–4% SBS (styrene-butadiene-styrene) or 3–6% APP (atactic polypropylene) to raise low-temperature flexibility while keeping high-temperature stiffness.
Low Temperature Bitumen Grades and Specifications
The table below compares the most commonly traded low-temperature and reference grades. Values are typical mid-range specifications; actual limits follow the applicable standard (EN 12591, ASTM D946, or AASHTO M20).
| Grade | Penetration @25 °C (dmm) | Softening Point (°C) | Fraass Breaking Point (°C) | Typical Use |
|---|---|---|---|---|
| 40/60 | 40–60 | 48–56 | −12 to −15 | Cold-climate paving |
| 60/70 (standard) | 60–70 | 49–56 | −8 to −10 | Reference grade, temperate |
| 80/100 | 80–100 | 45–52 | −10 to −12 | Cooler regions |
| 100/150 | 100–150 | 42–50 | −12 to −18 | Cold paving, membranes |
| 200/300 | 200–300 | 35–45 | −18 to −25 | Very cold climates |
| SBS PMB (low-temp) | 45–65 | 60–75 | −20 to −30 | High-performance paving |
Comparison note: Moving from standard 60/70 to an SBS-modified low-temperature grade can improve the Fraass breaking point by 10–15 °C, at a cost premium of roughly 15–25% per tonne depending on the polymer content and base stock.
| Parameter | Standard 60/70 | Low-Temp Grade | Improvement |
|---|---|---|---|
| Fraass breaking point | −9 °C | −20 °C | 11 °C |
| Workable paving temp (min) | +10 °C | −5 °C | 15 °C |
| Thermal crack resistance | Moderate | High | — |
| Rutting resistance @60 °C | High | Moderate–High | Slight reduction |
Why Low Temperature Performance Matters
Low-temperature failure is one of the most expensive pavement distress modes because it is not repairable with surface treatments. A single thermal crack allows water ingress, which drives freeze-thaw damage and accelerates structural deterioration.
The mechanics are straightforward:
- Thermal contraction. As asphalt cools from placement temperature to ambient, it contracts. If the induced tensile stress exceeds the binder's tensile strength, a crack initiates.
- Glass transition. Below roughly −20 °C to −30 °C, most bitumens enter a glassy state and lose all relaxation capacity.
- Aging. Oxidative aging raises stiffness and lowers the effective breaking point by 3–8 °C over a 10-year service life.
Practical consequences by application:
- Paving: thermal cracking in cold regions accounts for a significant share of maintenance budgets; specifying a Low-temperature grade can extend crack-free service life by 3–7 years.
- Roofing membranes: APP and SBS membranes must remain flexible during winter installation; a membrane that cracks at −10 °C is unusable in Nordic or Canadian markets.
- Waterproofing & coatings: cold-applied and hot-applied systems need ductility to bridge substrate movement.
Selection Criteria: Choosing the Right Grade
Selecting a low temperature bitumen is a balancing act between cold flexibility and hot-weather stability. The following decision framework is widely used by exporters and contractors.
Step 1 — Define the climate minimum.
- Mild cold (down to −10 °C): 80/100 or low-modulus 60/70.
- Severe cold (down to −25 °C): 200/300 or SBS PMB.
- Extreme cold (below −30 °C): highly modified PMB or soft grades with additives.
Step 2 — Check the high-temperature requirement.
- Soft grades rut easily above 55 °C; if summer pavement temperatures exceed 60 °C, polymer modification is required.
Step 3 — Verify compatibility.
- SBS-modified binders must be stored at 150–170 °C and used within 48–72 hours of production to avoid phase separation.
- Do not mix incompatible chemistries (e.g., certain wax-modified and SBS systems) without supplier confirmation.
Step 4 — Confirm documentation.
- Request a Certificate of Analysis (CoA) with penetration, softening point, Fraass (or equivalent), and ductility values.
- For export, confirm compliance with EN 12591 or ASTM D946.
Quick reference table:
| Climate Minimum | Recommended Grade | Typical Loading Temp |
|---|---|---|
| −10 °C | 80/100 | 140–150 °C |
| −15 °C | 100/150 | 145–155 °C |
| −20 °C | SBS PMB 45–65 | 155–170 °C |
| −25 °C | 200/300 | 140–150 °C |
Pricing, Packaging, and Supply Considerations
Low temperature bitumen pricing tracks crude feedstock and freight more than grade complexity, but the low-temperature premium is real. The table below reflects typical indicative ranges — always confirm live quotes.
| Grade | Indicative FOB Price (USD/MT) | Premium vs 60/70 | Standard Packaging |
|---|---|---|---|
| 60/70 (reference) | Base | — | 150–200 kg drums, bulk |
| 80/100 | Base + $8–15 | 2–3% | Drums, bulk, jumbo bags |
| 100/150 | Base + $12–20 | 3–5% | Drums, bulk |
| SBS PMB low-temp | Base + $60–120 | 15–25% | Bulk (heated), drums |
| 200/300 | Base + $10–25 | 3–8% | Drums, bulk |
Logistics factors that change the landed cost:
- Freight mode. Bulk vessel shipments are cheapest per tonne; drum exports add $20–40/MT in packing and handling.
- Heating requirements. Polymer-modified grades need insulated or heated containers — add $15–30/MT for temperature-controlled logistics.
- Order size. A 20-foot container holds roughly 20–24 MT in drums; bulk parcels typically start at 500 MT for economic vessel freight.
- Lead time. Standard grades ship in 7–14 days; custom PMB blends often require 20–30 days from order to loading.
- Seasonality. Demand for low-temperature grades peaks in Q3–Q4 ahead of Northern Hemisphere winter, tightening availability and adding 2–5% to spot prices.
Quality checks before shipment:
- Penetration at 25 °C within ±5 dmm of spec.
- Softening point within ±3 °C.
- Fraass breaking point at or below contractual limit.
- Weight verification per drum (150 kg, 180 kg, or 200 kg net).
FAQ: Low Temperature Bitumen
What is the lowest temperature at which bitumen can be paved?
With standard 60/70, practical paving usually stops around +10 °C. Low-temperature grades and SBS-modified binders extend the working window to as low as −5 °C, provided the mix design and compaction equipment are adjusted accordingly.
What is the Fraass breaking point and why does it matter?
The Fraass breaking point is the temperature at which a bitumen film fractures under defined test conditions. Lower values (e.g., −20 °C versus −9 °C) mean the binder tolerates more thermal contraction before cracking, which directly governs cold-climate performance.
Is SBS-modified bitumen better than soft penetration grades for cold climates?
SBS modification generally delivers the best combination of low-temperature flexibility (Fraass −20 to −30 °C) and high-temperature rutting resistance. Soft grades like 200/300 are cheaper but weaker under summer heat, so SBS is preferred where both extremes occur.
How much does low temperature bitumen cost compared to standard 60/70?
Soft low-temperature grades carry a 2–8% premium, while SBS-modified low-temperature binders cost 15–25% more per tonne. Freight, packaging, and heating requirements can add a further $15–40/MT to the landed price.
How should low temperature bitumen be stored and shipped?
Store at 140–170 °C depending on grade, avoid prolonged heating above 180 °C, and use within 48–72 hours for polymer-modified types. For export, specify insulated or heated containers, confirm a CoA per batch, and verify net drum weights before loading.
Calculate Your Low Temperature Bitumen Cost Instantly
Grade selection is only half the decision — landed cost decides the deal. Before you request a quote, run your volumes, grade, packaging, and destination through the 6Tar cost calculator to get an instant indicative price per tonne and per container. It factors in grade premium, freight mode, packaging, and heating surcharges, so you can compare 60/70, 80/100, 100/150, SBS PMB, and 200/300 side by side in under a minute. Get your number, then negotiate with confidence.