IS 8887:2018 is the Indian Standard (BIS) for cationic bitumen emulsion - specification. This standard specifies the requirements, grades, and testing methods for cationic bitumen emulsions used in road construction and maintenance. It covers various types like Rapid Setting (RS), Medium Setting (MS), and Slow Setting (SS) emulsions, detailing their properties such as viscosity, binder content, and storage stability.
Specifies requirements for various grades of cationic bitumen emulsion used in different road construction and maintenance applications.
Grades and where each is used.
| Reference | Value | Clause |
|---|---|---|
| RS (RS-1/RS-2) | Rapid set — surface dressing, penetration macadam | Grades |
| MS | Medium set — premix patch / mixes | Grades |
| SS (SS-1/SS-2) | Slow set — tack coat, fog seal, slurry/micro | Grades |
| Tack coat grade | SS-1 (slow setting) | Application |
| Particle charge | Must be positive (cationic) | Acceptance |
| Lay overlay | Only AFTER the emulsion breaks (brown→black) | Hold point |
| Check | Residue (bitumen content) + recovered penetration | Acceptance |
IS 8887:2018 is the specification for cationic bitumen emulsion — water-based bitumen (positively-charged droplets) used cold for tack coats, prime coats, surface dressing, fog seals, slurry seal/micro-surfacing and patch repair. It is the binder code whenever bitumen is applied without heating to spraying temperature, which is most maintenance and many surfacing operations.
It is read with the road-binder and pavement stack:
Cationic emulsions are graded by how fast they 'break' (the bitumen separating from water and bonding to the aggregate/surface):
Key acceptance properties in IS 8887: residue by evaporation/distillation (bitumen content), viscosity (sprayability), particle-charge test (must be positive/cationic), storage stability, sieve residue, coagulation/stability, and the penetration/ductility of the recovered binder (the actual bitumen quality after the water is gone). Grade selection is dictated by the *operation*, not preference.
Task: tack coat between an existing bituminous surface and a new DBM overlay.
Step 1 — grade: a tack coat must stay workable and bond to a dense surface → SS-1 (slow setting) cationic emulsion.
Step 2 — surface prep: the existing surface is cleaned and dried — tack on dust or standing water never bonds (the commonest delamination cause).
Step 3 — application rate: sprayed at the MoRTH-specified residual-bitumen rate for the surface type (a thin, uniform film — over-application creates a slip plane, not a bond).
Step 4 — break/cure: allow the emulsion to break and the water to leave (colour turns brown→black) before laying the overlay — paving on un-broken emulsion traps water and bleeds.
Step 5 — accept: verify on the delivered emulsion: positive particle-charge, residue (bitumen content) and viscosity per IS 8887 for the grade, plus recovered-binder penetration. Lay the overlay only after the tack has broken.
1. Wrong grade for the operation. RS where SS is needed (or vice-versa) breaks too fast/slow — no bond, or no workability. Grade follows the job.
2. Paving before the emulsion breaks. Overlaying brown (un-broken) emulsion traps water → stripping, bleeding and early failure. Wait for the break.
3. Over-application of tack. A heavy tack film is a *slip plane* between layers, not a stronger bond — apply the specified thin uniform rate.
4. Dirty/wet substrate. Emulsion cannot bond through dust or to a wet surface; preparation is most of the job.
5. No charge/residue test. Confirm it is genuinely cationic (positive particle charge) and has the specified bitumen residue — diluted or anionic product looks identical in the drum and fails on the road.
Cationic emulsions have largely displaced anionic and cutback binders for cold and maintenance work because they bond well to most Indian (siliceous) aggregates, are safer (no heating, no solvent), and are environmentally preferable — IS 8887:2018 is a reasonably current revision aligned with this practice. Specify by grade for the operation (SS for tack/slurry, RS for surface dressing) and always check the recovered-binder properties, not just the emulsion-state tests, because the road only ever sees the residual bitumen.
The field failures are almost always procedural, not material: tack applied on a dirty/wet surface, overlay laid before the emulsion breaks, or the wrong setting grade. Write the grade, surface-prep, application rate and a 'lay only after break' hold point into the method statement and ITP — that converts IS 8887 compliance from a drum certificate into an actual bonded pavement.
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Storage Stability (24h), % max (for RS-1 / CRS-1) | 2.0 | 1.0 | ASTM D2397 |
| Residue Penetration @ 25°C, dmm (for RS-1 / CRS-1) | 80-150 | 100-250 | ASTM D2397 |
| Viscosity, Saybolt Furol @ 50°C, s (for MS Grade / CMS-2) | 50-300 | 50-450 | ASTM D2397 |
| Viscosity, Saybolt Furol @ 50°C, s (for RS-1 / CRS-1) | 20-100 | 20-100 | ASTM D2397 |
| Sieve Test, % max (all grades) | 0.1 | 0.1 | ASTM D2397 |
| Residue by Distillation, % min (for RS-1 / CRS-1) | 60 | 60 | ASTM D2397 |
| Elastic Recovery of Residue @ 15°C, % min (for PME) | 50 | Not explicitly defined in the same way; polymer grades like CRS-2P have different requirements. | ASTM D2397 |