HFMS-2 Bitumen Emulsion
Last updated: 2026-10-01
HFMS-2 bitumen emulsion is a cationic, medium-setting, high-float grade manufactured to ASTM D977 / AASHTO M208, containing 57–63% residual bitumen by weight. It is supplied at $420–$560 per tonne FOB (bulk, 2024–2025 range), typically in 20–24 tonne flexitanks or ISO tank shipments, and is engineered for slurry seals, micro-surfacing and chip seals where aggregate retention and low-temperature flexibility matter most. HFMS-2 sets in 30–90 minutes under normal ambient conditions, faster than HFMS-1 and slower than rapid-setting CRS grades.
What Is HFMS-2 Bitumen Emulsion? Definition, Chemistry and Specifications
HFMS-2 stands for High-Float Medium-Setting, Type 2. In the ASTM D977 naming system:
- H (High-Float) — the emulsion contains a float additive (typically tall oil or a fatty amine surfactant) that lets the bitumen "float" on the surface rather than penetrate, making it ideal for seal coats with high absorption aggregates.
- M (Medium-Setting) — the emulsion breaks at a controlled, moderate rate, giving crews 30–90 minutes of workability.
- S (Slow-setting residue) — once the water evaporates, the residual binder behaves as a slow-curing material, remaining workable longer.
- 2 — higher viscosity and higher residue content than Type 1.
| Property | Specification Range | Typical Value | Test Method |
|---|---|---|---|
| Residue by evaporation | 57% min | 60–63% | ASTM D6997 |
| Viscosity, Saybolt Furol 25°C | 20–100 SSF | 40–65 SSF | ASTM D7496 |
| Storage stability, 24 h | 1% max | 0.3–0.8% | ASTM D6930 |
| Particle charge | Positive (cationic) | Positive | ASTM D7402 |
| Sieve test, 850 µm | 0.1% max | 0.02–0.05% | ASTM D6933 |
| Cement mixing | 2.0% max | 1.5% | ASTM D6935 |
| pH | 2.0–7.0 | 3.5–5.5 | ASTM E70 |
| Penetration, 25°C (residue) | 40–90 dmm | 60–70 dmm | ASTM D5 |
| Softening point (residue) | 45–60°C | 50–55°C | ASTM D36 |
| Ductility, 25°C (residue) | 40 cm min | 65–80 cm | ASTM D113 |
| Residual binder (on total solids) | ~60–63% | 61% | Calculated |
Key chemistry: HFMS-2 uses a cationic emulsifier system — usually a mixture of tallow amine and ethoxylated amine surfactants — acidified with hydrochloric or acetic acid to a pH of 2.0–7.0. The positive charge on the bitumen droplets makes the emulsion bond strongly to negatively charged aggregates: siliceous (granite, quartz) stones, most sand and gravel, and recycled asphalt pavement (RAP).
The "float" additive is the defining feature. It reduces surface tension and slows penetration into porous substrates, so the binder film stays at the surface where it seals and grips aggregate chips.
HFMS-2 vs Other Bitumen Emulsions: Full Comparison Table
Buyers frequently compare HFMS-2 against HFMS-1, CRS-2, SS-1h, and CMS-2h. The differences determine application fit, cost and shipping economics.
| Grade | Setting Speed | Residue % | Charge | Best Application | Typical Price (FOB, $/tonne) |
|---|---|---|---|---|---|
| HFMS-2 | Medium | 57–63% | Cationic | Micro-surfacing, slurry seal, chip seal | 420–560 |
| HFMS-2h | Medium | 63% min | Cationic | High-residue micro-surfacing | 460–590 |
| HFMS-1 | Medium | 57% min | Cationic | Lower viscosity fog seal, tack coat | 400–530 |
| CRS-2 | Rapid | 65–67% | Cationic | Tack coat, prime, immediate chip seal | 440–580 |
| CMS-2h | Medium | 65% min | Cationic | Cold mix, slurry, high-residue work | 450–575 |
| SS-1h | Slow | 57% min | Anionic | Cold recycling, soil stabilization, tack | 390–510 |
| CSS-1h | Slow | 57% min | Cationic | Penetrating prime, tack, dust suppression | 410–525 |
Selection logic for buyers:
- Choose HFMS-2 when the job needs high aggregate retention on a coarse, porous surface, moderate traffic opening time (1–4 hours), and a sprayable viscosity that won't drain off slopes.
- Choose HFMS-2h for micro-surfacing where a thicker binder film is required (63%+ residue).
- Choose CRS-2 when the road must reopen in 15–30 minutes.
- Choose SS-1h / CSS-1h when penetration into the base is the goal rather than a surface film.
Shipping note: Because HFMS-2 carries only ~60–63% bitumen, you pay freight on ~38% water. In a 24-tonne flexitank you receive roughly 14.5–15 tonnes of residual binder. This is why residue content directly drives landed cost.
Price, Packaging and Lead Times: What Importers Actually Pay
HFMS-2 is traded in bulk, in flexitanks, and in drums. Pricing depends on crude oil benchmarks (the bitumen input tracks Brent and HSFO), the emulsion grade, order size, and delivery terms.
| Packaging | Unit Size | Residual Binder | FOB Price/tonne | Landed Price Example (CIF, distant port) |
|---|---|---|---|---|
| Flexitank | 20–24 tonnes | ~14.5 t | $420–$560 | $520–$640 |
| ISO tank | 20–24 tonnes | ~14.5 t | $440–$580 | $540–$660 |
| Steel drum | 200 kg (150 kg net) | ~92 kg | $520–$680 | $640–$780 |
| IBC tote | 1,000 kg | ~610 kg | $490–$630 | $600–$740 |
Freight and logistics benchmarks:
- Flexitank in a 20-ft container: 20–24 tonnes emulsion; loading/unloading via pump.
- ISO tank: 21–24 tonnes; 5–7 day lead time for equipment positioning at most origins (UAE, Iran, Turkey, Malaysia, Singapore).
- Transit time: UAE → East Africa: 5–12 days; UAE → India: 4–8 days; Far East → West Africa: 25–35 days.
- Documentation lead time: 3–5 working days for COA, MSDS, ASTM test reports, certificate of origin.
Cost benchmark clients use to compare projects: the 6Tar cost calculator. Plug in emulsion price per tonne, residue content, application rate (kg/m²) and coverage area to get cost per m² and per km. For a typical micro-surfacing job:
| Application | Spread Rate | Binder Needed per km (6 m wide) | Cost/km at $500/t |
|---|---|---|---|
| Slurry seal | 1.2 kg/m² | 4.32 t (with 60% residue) | $3,240 |
| Micro-surfacing | 1.8 kg/m² | 6.48 t | $3,888 |
| Chip seal | 1.5 kg/m² | 5.40 t | $3,240 |
Applications of HFMS-2 Bitumen Emulsion
HFMS-2 is a workhorse in pavement preservation. Its high-float behavior and medium-setting break deliver strong results in five main applications.
The most common use. HFMS-2's medium set allows the mixture to be mixed, spread and leveled by a paver before breaking. The high-float additive improves aggregate suspension and reduces segregation during transport. Typical job mix: 8–12% emulsion by weight of aggregate, applied at 6–10 mm thickness.
- Coverage: 1.5–2.5 kg/m² of emulsion
- Cure time before traffic: 45–90 minutes
- Traffic opening: 60–120 minutes in 25°C weather
HFMS-2 is sprayed at 1.2–1.8 kg/m² (residual binder 0.6–1.0 kg/m²), then aggregate chips (10 mm, 14 mm) are rolled in. High-float chemistry keeps binder at the surface for excellent chip retention — typically 95%+ retention after 24 hours when aggregate is clean and damp.
HFMS-2 is used as a tack coat between old and new asphalt layers or under concrete. Application rate: 0.2–0.5 kg/m² residual binder. Because it is cationic, it bonds well to both asphalt and concrete.
Diluted 1:1 to 1:3 with water, HFMS-2 restores aged surfaces and reduces dust on unpaved shoulders. A 1:3 dilution gives roughly 15% residual binder, ideal for light surface enrichment.
Medium-set cationic emulsions are compatible with RAP and cold mix designs. Typical dosage: 3–6% by weight of RAP.
Handling, Storage and Quality Checks
HFMS-2 is a water-based product and must be treated carefully to stay in spec.
- Storage temperature: 10–45°C. Protect from freezing (below 5°C) and overheating (above 60°C).
- Storage stability: 1% max sediment after 24 h — store in tanks with gentle agitation or recirculate every 3–5 days.
- Shelf life: 3–6 months in sealed containers under normal conditions. Flexitanks should be used within 60 days of arrival.
- pH check: 2.0–7.0 on arrival. A pH outside range indicates contamination or a formulation issue.
- Pumping: Positive displacement or gear pumps; avoid high-shear pumps that can shear the emulsion.
- Never mix with anionic emulsions (SS-1, SS-1h) — the charges will cancel and the emulsion will break in the tank.
| Check | Spec | Action if Out of Spec |
|---|---|---|
| Residue by evaporation | 57% min | Reject or renegotiate |
| Sieve test | 0.1% max | Reject if >0.1% |
| Storage stability (24 h) | 1% max | Reject if >1% |
| Cement mixing | 2.0% max | Reject if >2.0% |
| Particle charge | Positive | Reject if negative |
| COA vs. sample | Match | Flag to supplier |
FAQ: HFMS-2 Bitumen Emulsion
What does HFMS-2 stand for in bitumen emulsion?
HFMS-2 means High-Float (H), Medium-Setting (M), Slow-setting residue (S), Type 2. It is a cationic emulsion with 57–63% residual bitumen, a float additive for surface sealing, and a 30–90 minute working window, per ASTM D977 and AASHTO M208.
What is the price of HFMS-2 bitumen emulsion per tonne?
HFMS-2 typically costs $420–$560 per tonne FOB in bulk (2024–2025), rising to $520–$640 CIF at distant ports. Flexitank and ISO tank shipments of 20–24 tonnes are the most economical. Drummed material costs $520–$680 per tonne.
What is the difference between HFMS-2 and HFMS-2h?
HFMS-2h has a minimum 63% residue versus 57% for HFMS-2. The higher binder content makes HFMS-2h better for micro-surfacing and high-build applications, while HFMS-2 is more common for standard slurry seals and chip seals. HFMS-2h costs roughly $40–$60 per tonne more.
How many tonnes of HFMS-2 fit in one container?
A 20-ft container with a flexitank holds 20–24 tonnes of HFMS-2 emulsion, which equals about 12–15 tonnes of residual binder at 60–63% residue. An ISO tank holds a similar 21–24 tonnes.
Is HFMS-2 the same as CRS-2?
No. CRS-2 is a rapid-setting emulsion that breaks in 15–30 minutes and has 65–67% residue, while HFMS-2 is medium-setting with 57–63% residue and a 30–90 minute window. HFMS-2 also contains a high-float additive that CRS-2 does not.
Closing: Price HFMS-2 for Your Project in Under 60 Seconds
HFMS-2 spec sheets are easy to read — but