Reference Specifications for Civil Engineering Work 2001

8.base RESTORATION

Existing Granular Pavements

Use Class 1 unbound pavement material or structural asphalt to match depth of existing pavement unless approved otherwise. Where structural asphalt is used, subsoil drainage (Standard Drawing BSD-2041) is to be installed on the uphill side of the trench unless approved otherwise by Council.

Existing Asphalt Pavements

Reinstate existing sub-surface drainage to comply with Standard Drawing BSD-2041.

Sub-surface Pavement Drainage

Material selection: Choose base course material to suit the permeability characteristics of the existing pavement base to ensure that the reinstated pavement does not hold water nor obstruct existing drainage paths through the pavement.

Materials

Permitted materials: Comply with the requirements of Standard Drawing BSD-2042. For isolated patches less than 2 m² in size, use full depth asphalt.

Material selection: Choose base course material to suit the permeability characteristics of the existing pavement base to ensure that the reinstated pavement does not hold water nor obstruct existing drainage paths through the pavement.

Structural asphalt: BCC Type 3 mix (18 mm nominal aggregate size) or BCC Type 4 mix (35 mm nominal aggregate size), both containing multigrade bitumen binder. Limit the thickness of each compacted layer to 50 - 80 mm for BCC Type 3 mix and 70 - 100 mm for BCC Type 4 mix.

Class 1 unbound pavement material: Comply with the requirements of Reference Specification S300 Quarry Products. Alternatively, use Queensland Department of Transport and Main Roads Type 2 unbound material, Subtype 2.1. Achieve a minimum relative compaction of 95% of the modified maximum dry density to AS 1289.5.2.1.

Permitted materials: Comply with the requirements of Standard Drawing BSD-2042. For isolated patches less than 2 m² in size, use full depth asphalt.