IS 9167 covers bitumen emulsion — bitumen dispersed in water with an emulsifier. Used for tack coat (between pavement layers), prime coat (on granular base), surface dressing, and cold mix. Applied at ambient temperature unlike hot bitumen (IS 73).
Specification for bitumen emulsion (anionic and cationic) used for tack coat, prime coat, surface dressing, and cold mix applications in road construction.
Key Values
CRS-1 bitumen contentMin 60%
CMS-2 bitumen contentMin 65%
Tack coat applicationSS-1 at 0.2-0.3 litres/m²
Practical Notes
! Cationic emulsions (CRS, CMS, CSS) are preferred in India — they work with most aggregate types.
! SS-1 (slow setting) is the standard for tack coat between bituminous layers.
! Emulsion must be applied at ambient temperature (no heating) — this is its main advantage over hot bitumen.
! Do not dilute emulsion more than recommended — over-dilution causes inadequate bonding.
! Emulsion breaks (separates water) when it contacts aggregate — breaking time determines the setting type.