Emulsions
It is recommended to select emulsions based on the bitumen percentage and degradation rate.
The lower the number behind B (B2-B5) is, the faster the emulsion reacts with dust and fine granules. The higher the number behind C (C35-C71) is, the higher the bitumen % in the emulsion will be, meaning the emulsion is thicker in use and requires higher temperatures for both storage and use.
From a storage perspective, it is important that the emulsion is as slow as possible and with a low bitumen percentage. This means that the product can be stored at lower temperatures and for longer without damage to the emulsion’s quality.
Degradation rate does not mean that a faster emulsion would adhere rock to the road surface faster and the work would be completed faster. In reality, the degradation rate shows a reaction with dust and fine granules (this is also used in testing) and if there is a lot of these on the rock and surface, then an overly fast emulsion (B2, B3) has no time to permeate the dust in liquid state and immediately transforms into bitumen without strongly bonding with the rocks’ pores. Without a strong connection, water can penetrate the result and break the weak bond.
This means that, in case of dusty and unwashed rock, it is recommended to use a slower emulsion (B4) that does not immediately react with a dirty surface and has time to permeate the rocks’ pores in a liquid state, hence creating a strong and waterproof contact.
