4.8.1 Binder Type
The binder types listed in Table 4.6 can be considered as typical for those applications, however other binder types can be used.
The choice of binder is mainly influenced by the prevailing weather conditions, as well as the desired life of the treatment, and timing and type of final treatment.
The requirements for AMC cutback bitumen grades are provided in AS 2157. Equivalent field‑blended grades may also be used.
Bitumen emulsions may be considered when a secondary surfacing is to be applied before adequate curing of a cutback bitumen binder can occur. The requirements for bitumen emulsion grades are provided in AS 1160.
Where a pavement stabilised with cementitious or chemical binder is to be initial sealed using a bitumen emulsion, a check on the compatibility of the emulsion with the stabilised material should be undertaken. Emulsions will always be compatible with bitumen stabilised pavements.
Binders for very heavy traffic and/or warm to hot conditions include proprietary grades of polymer modified binder, polymer modified emulsion, cutback bitumen manufactured with Class 320 base bitumen in place of Class 170, and cutback bitumen with low proportions of cutter oil. These binders provide for more rapid curing and reduced risk of bleeding in more demanding performance applications.