Surface course mixtures
The use of higher binder content (Bact) in AC6 and AC10 mixtures than those detailed in PD 6691 Table B14 and B15 has been included to provide options for mixtures that have enhanced workability and reduce risks associated with air voids non-compliance. Care should be taken to avoid loss of texture or reduced resistance to rutting associated with an excessive increase in binder content. Liaison with the asphalt supply chain is recommended to optimise the benefits of adopting this type of material. It is the future intention to include specific provision for these mixtures in PD 6691.
Limited use of AC10 without agreement in footways, footpaths and cycle tracks has been included to enable efficient use of materials and it is not intended as a wholesale replacement for the preferred option of AC6 for this application.