Bitumen CSS: Slow-Setting Cationic Emulsion for Mixing,and Durable Surface Treatments

What is Bitumen CSS

Bitumen CSS (Cationic Slow Setting) is a water-based bitumen emulsion designed to remain workable for extended periods. Unlike CRS or CMS grades, CSS breaks slowly, giving contractors enough time to thoroughly mix it with mineral fines and aggregates. This makes it the preferred emulsion for slurry seal, micro-surfacing, fog sealing, and stabilization projects.

Why Contractors and Buyers Choose Bitumen CSS

• Extended working time – Ensures proper coating of aggregates and fines.

• Cold-applied efficiency – No heating required, reducing fuel and equipment costs.

• Cationic adhesion – Bonds strongly to damp or dusty aggregates.

• Versatility – Used for slurry seals, fog seals, and cold mixes.

• Specification-friendly – Meets ASTM/AASHTO requirements, easing project approvals.

• Logistics-ready – Available in drums, IBC tanks, or bulk for international trade.

Primary Applications of Bitumen CSS

Slurry Seal and Micro-Surfacing

CSS provides the slow breaking action needed for uniform coating of mineral fines and aggregates, ensuring durability and skid resistance.

Fog Sealing

When diluted, CSS penetrates oxidized pavements, sealing micro-cracks, restoring flexibility, and improving appearance.

Cold Mix and Stabilization

Useful in soil stabilization and patching works where controlled emulsion–aggregate interaction is needed.

Dust Control

Applied on unpaved surfaces to bind fine particles, improving safety and reducing maintenance costs.

How Bitumen CSS Creates Business Value

For contractors, CSS allows consistent mixing windows and smoother operations on site.
For distributors, it reduces inventory complexity by covering multiple maintenance applications with one product.
For road agencies, CSS aligns with sustainability goals by being a cold-applied emulsion that extends pavement life at lower lifecycle cost.

Application Guidance

• Aggregate moisture – Slight surface dampness is acceptable, but free water should be avoided.

• Mixing sequence – Emulsion should be added to the aggregate, not the other way around.

• Dilution – Only dilute with clean water and according to specifications.

• Curing – Allow sufficient curing before opening roads to traffic.

• Weather – Best performance in dry weather with warm surface temperatures.

Packaging, Logistics, and Quality Controls

Bitumen CSS is shipped in 200 kg new steel drums, 1,000 L IBC tanks, or bulk tankers. Quality reports such as a Certificate of Analysis ensure compliance with buyer specifications. Proper storage and rotation (FIFO) maintain consistency during shipment and handling.

Storage and Handling Recommendations

• Store in a shaded, ventilated area.

• Do not allow the emulsion to freeze.

• Gently agitate before use to restore homogeneity.

• Use standard protective equipment during handling.

Frequently Asked Questions (FAQ)

Q1: When should I use Bitumen CSS instead of CRS or CMS?

A: Use CSS when you need longer mixing and placement time, such as in slurry seals, micro-surfacing, or fog seals.

Q2: Can Bitumen CSS be diluted?

A: Yes, it can be diluted with clean water for fog sealing or tack coats, depending on project specifications.

Q3: Does CSS work with damp aggregates?

A: Yes, its cationic charge helps it bond to slightly damp aggregates, though excess water should be avoided.

Q4: How soon can roads reopen after using CSS?

A: Cure time depends on weather and film thickness. It is slower than CRS, so additional curing time may be required.

Q5: What quality checks are important before delivery?

A: Key tests include viscosity, residue on evaporation, penetration, ductility, and storage stability.