6.1.3 Design Voids Factor
The design voids factor,VF, is now calculated by Equation 5:
Design voids factor, VF = Vf + Va + Vt | 5 | ||||||||
where | |||||||||
Vf | = | basic voids factor | |||||||
Va | = | adjustment for aggregate shape | |||||||
Vt | = | adjustment for traffic effects |
If adjustments for aggregate shape and traffic effects result in a reduction in the basic voids factor of 0.04 L/m2/mm or more, special consideration should be given to the suitability of the treatment and possible selection of alternative treatments.
Selection of an alternative type of treatment should be considered where the design voids factor is at, or close to, the minimum recommended value of 0.10 L/m2/mm. For example, use of a PMB to aid aggregate retention or a double/double seal to provide a more robust treatment.