6.3 Binder Factor
The type of binder used in a sprayed seal effects the required application rate. The design process achieves this by using 'binder factors’ that are specific to the different treatments and type of binder.
All polymer modified binders are more viscous and elastic than conventional binder and may be used at higher rates of application for increased effectiveness.
High bitumen content emulsions reduce aggregate reorientation as a result of a rapid increase in binder stiffness after the initial breaking and curing of the emulsion, and may be used at higher rates of application to compensate for this.
Binder factors are applied to polymer modified binders for both hot applied, and emulsion delivery systems.
The binder factor is applied to the basic binder application rate, to create a modified basic binder application rate, Bbm, which is calculated using Equation 7:
| Modified basic binder application rate, Bbm = Bb x BF (rounded to nearest 0.1 L/m²) | 7 | |||
| where | ||||
| Bb | = | basic binder application rate | ||
| BF | = | binder factor |