What is the meaning of Emulsion Bitumen’grades?
Bitumen Emulsions are classiﬁed in British Standard (also Kenya Standard & Australia standard) which being defined by a three-parts.
1. The ﬁrst part, either A or K, indicates anionic or cationic emulsion.
2. The second, 1 to 4, indicates the breaking rate or stability (the higher the number, the greater the stability or the slower the break).
3. The third part of the code indicates the bitumen content of the emulsion as a percentage of the total.
for example ;
K1-70: a cationic emulsion, rapid breaking with a bitumen content of 70%
A2-50: an anionic emulsion, semi-stable with a bitumen content of 50%.
The Standard speciﬁes bitumen emulsions in terms of:
- Particle charge;
- Sieve residue 1 (coarse sieve, 710mm);
- Sieve residue 2 (ﬁne sieve, 150mm);
- Viscosity is an eﬄux time from a ﬂow cup (degrees Engler or Redwood II seconds);
- Coagulation at low temperature;
- Storage stability (short period test);
- Storage stability (long period test);
- Stability of mixing with coarse aggregate;
- Stability of mixing with cement;
- Bitumen content*.
* The test method speciﬁed in fact measures water content with ‘bitumen content’ deﬁned as the diﬀerence between water content and 100%, thus ‘bitumen content’ includes emulsiﬁer and solvent.