Bitumen Emulsion CSS-1h | Tack Coat Supplier Turkey & UAE

Key Properties of Cationic Bitumen Emulsion CSS-1h

ASTM D2397 Full Specification — Cationic Bitumen Emulsion CSS-1h

FOB Price — Cationic Bitumen Emulsion CSS-1h

Why CSS-1h is the Premium Tack Coat for Hot Climates

CSS-1h combines the two most important performance characteristics for road construction in tropical and arid climates: the cationic charge of CSS-1, which enables bonding with siliceous aggregates and wet surfaces, and a harder bitumen residue (penetration 40–90 dmm) that resists deformation at elevated pavement temperatures.

In countries where pavement surface temperatures regularly reach 55–65°C — across Nigeria, Kenya, Iraq, Saudi Arabia, Bangladesh, and Pakistan — a soft tack coat residue becomes viscous and allows relative movement between asphalt layers under heavy vehicle loading. This creates a slippage failure plane, leading to wheel-path cracking, delamination, and premature pothole formation. CSS-1h’s harder residue remains stable at these temperatures, locking pavement lifts together as a single structural unit. This is why CSS-1h is commonly specified by road authorities in the Gulf Cooperation Council, East Africa Road Network, and South Asian national highway programs for all primary and secondary highway tack coat applications.

CSS-1h also does not track under construction traffic after breaking — a practical advantage on busy construction sites where equipment must cross freshly tack-coated surfaces before the overlay is placed.

Applications of Cationic Bitumen Emulsion CSS-1h

Tack Coat — primary application (0.2–0.5 L/m²): CSS-1h is sprayed onto existing asphalt, concrete, or milled pavement surfaces before placement of a new hot mix or cold mix asphalt overlay. The cationic charge ensures strong adhesion even on surfaces that are slightly damp or dusty. The hard residue (40–90 dmm) prevents the bonded interlayer from softening and allowing slippage under traffic in hot weather. Apply undiluted at 0.2–0.3 L/m² on clean dense surfaces and 0.4–0.5 L/m² on milled or open-graded surfaces. Allow the emulsion to break fully — colour changes from brown to uniformly black — before placing the overlay.

Fog Seal (0.3–0.6 L/m², diluted 1:1): Applied to aged or oxidised asphalt surfaces to seal micro-cracks, reduce ravelling, and restore surface impermeability. CSS-1h’s cationic charge bonds strongly to siliceous aggregate surfaces and its harder residue resists tracking under traffic after breaking — making it more durable than CSS-1 for fog sealing on high-traffic roads in hot climates.

Slurry Seal and Microsurfacing: CSS-1h is the standard cationic emulsion binder for slurry seal and microsurfacing systems. It is mixed with well-graded fine aggregate, mineral filler, water, and additives to produce a workable slurry that is spread over the pavement surface. The slow-setting nature ensures extended spreading time, while the harder residue provides improved durability and skid resistance after curing — particularly important on high-speed and high-traffic road sections.

Dense-Graded Cold Mix Patching: CSS-1h is mixed with dense-graded aggregate at a central plant or in-situ for cold-storable patching material. The slow setting allows extended workability during stockpiling and application. CSS-1h provides better long-term stability in stockpiled cold mix than CSS-1 due to its harder residue.

Base Stabilisation: CSS-1h can be used for in-situ stabilisation of granular or laterite base courses as part of pavement rehabilitation. Applied by mixing or injection into the base material, CSS-1h coats aggregate particles, binds fines, and after curing improves the load-bearing capacity and moisture resistance of the base layer.

Dust Control (diluted 1:2 to 1:3 with water): Sprayed at 0.5–2.25 L/m² on unpaved roads to bind loose surface particles. The cationic charge bonds effectively with siliceous and lateritic dust particles, providing durable dust suppression on granite and basalt-derived gravel road surfaces in Africa and South Asia.

CSS-1h vs CSS-1 vs SS-1h — Full Comparison

CSS-1h Dilution Guide

CSS-1h can be diluted with clean potable water immediately before application. Always add water slowly to the emulsion while stirring — never add emulsion to water. Do not use seawater or hard water containing calcium or magnesium salts. Maximum dilution ratio is 1:1. Never mix with anionic emulsions (SS-1, SS-1h) as immediate coalescence will occur.

Packaging & Shipping

Cationic Bitumen Emulsion CSS-1h is exported in new steel drums (200 litres, sealed on pallets), IBC tanks (1,000 litres), or flexi tanks (16,000–20,000 litres in a 20ft container). Bulk tanker supply is available from our Iskenderun and Jebel Ali terminals. Flexi tank is the most cost-effective option for large-volume import orders at port terminals across Africa and South Asia.

Store between 5°C and 60°C in sealed containers away from direct sunlight. Do not freeze. Do not heat above 70°C. Do not mix with anionic emulsions or calcium-based materials. Shelf life: 4–6 months from production date in sealed, undisturbed containers.

Export Destinations

Zumrut International Kimya exports Cationic Bitumen Emulsion CSS-1h to road authorities, highway contractors, and bitumen traders across West Africa (Nigeria, Ghana, Senegal, Ivory Coast, Cameroon), East Africa (Kenya, Tanzania, Ethiopia, Uganda, Rwanda, Mozambique), the Middle East (Iraq, Saudi Arabia, Oman, Kuwait, Jordan, Yemen), and South Asia (Bangladesh, Sri Lanka, Pakistan). Shipments depart from Iskenderun Port (Turkey) and Jebel Ali Port (UAE) with lead times of 14–30 days.

Frequently Asked Questions — Cationic Bitumen Emulsion CSS-1h

What does CSS-1h mean in bitumen emulsion?

CSS-1h stands for Cationic Slow Setting, Grade 1, Hard residue. “C” indicates cationic — bitumen particles carry a positive charge for bonding with siliceous aggregates. “SS” indicates slow setting for extended workability. “h” indicates hard — the residual bitumen after distillation has a lower penetration (40–90 dmm) than standard CSS-1 (100–250 dmm), providing better rutting resistance and non-tracking performance in hot climates.

What is the difference between CSS-1h and CSS-1?

Both are cationic slow-setting emulsions meeting ASTM D2397. The only difference is residue hardness: CSS-1h (penetration 40–90 dmm) is significantly harder than CSS-1 (penetration 100–250 dmm). This makes CSS-1h the preferred tack coat grade for hot climates where pavement temperatures exceed 50°C, since the harder residue resists softening and prevents slippage between asphalt layers. CSS-1 is preferred for prime coat applications and cooler climates where binder flexibility is more important than rutting resistance.

Can CSS-1h be applied to wet pavement?

Yes — the cationic charge enables electrostatic bonding with aggregate surfaces even when damp, independently of water evaporation. CSS-1h can be applied to cool or slightly damp pavement surfaces, though standing water must be removed and the emulsion should not be applied during active rainfall. This wet-surface tolerance is a key advantage over anionic emulsions like SS-1h, particularly during tropical wet seasons.

How long does CSS-1h take to break?

Under typical conditions (25–40°C ambient, low to moderate humidity), CSS-1h breaks in 20–60 minutes after application, turning from brown to uniformly black. At higher temperatures in direct sunlight, breaking can occur in 15–30 minutes. In humid or overcast conditions, breaking may take up to 90 minutes. The overlay or aggregate must not be placed until breaking is complete. CSS-1h does not track under light construction traffic after breaking, unlike softer grades.

What is the difference between CSS-1h and SS-1h?

Both have identical hard residue characteristics (penetration 40–90 dmm) and are used as tack coat grades for hot climates. The difference is the particle charge: CSS-1h is cationic (positive) and bonds best with siliceous aggregates (granite, quartzite, basalt), while SS-1h is anionic (negative) and bonds best with calcareous aggregates (limestone, dolomite). CSS-1h also performs better on wet surfaces and breaks faster in cold or humid conditions. The choice depends on the aggregate type available and the local road authority specification.

Is CSS-1h suitable for airport pavement tack coat?

CSS-1h is widely used as a tack coat on airport taxiways, aprons, and runway shoulders where strong interlayer bond and non-tracking performance under aircraft ground loads are critical. Its hard residue prevents slippage under heavy aircraft wheel loads, and its cationic charge ensures reliable adhesion to both asphalt and concrete surfaces. For airside applications, always verify FAA, ICAO, or local airport authority specifications before use. Our technical team can provide full product documentation and test certificates to support specification approval.

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