Bitumen anionic slow setting SS1
Bitumen SS1 is anionic slow setting bitumen. The type of emulsifying agent used in the asphaltic emulsion determines if the emulsion will be cationic or anionic. The perception is cationic emulsions tend to break chemically whereas anionic emulsions tend to break evaporative. However this is primarily only a chip seal concern and not necessarily a tack concern.
The relative break of a tack may be more governed by the chemical loading of the emulsion and weather conditions than anything else. Anionic emulsions carry a negative charge whereas cationic ones carry a positive charge and by theory are best used with aggregates carrying an opposite charge.
Usage of Bitumen SS1
Slow-setting grades of emulsion used for tack coat is bitumen SS1.The original slow-setting emulsion, already containing a maximum of 43 percent water, is always diluted by adding up to an equal amount of water. In general, the dilution rate is less when it is cool or damp.
Slow-setting emulsion is most commonly used, however, they take longer to break than rapid-setting emulsions. For this reason, they are not recommended for use as a diluted tack coat in cold weather, at night, or when there is a short construction window.
Caution on using bitumen SS1
Slow-setting emulsions are not recommended for use as a diluted tack coat in cold weather, at night, or when there is a short construction window.