Infrastructure Development Code


No sub-base layer material shall be placed until the subgrade has been satisfactorily completed and approved by the Engineer.
The sub-base layer shall be constructed to the final shape as shown on the approved drawings.
NZTA Specification B/02 Construction of Unbound Granular Pavement Layers shall apply except as modified by the following:

  1. The reduced level of any point on the surface of the sub-base layer shall be within the limits 10mm above to 10mm below the designed or nominated level as established by stringing.
  2. Compaction of the sub-base layer shall be tested for acceptance as detailed in IT-4.2.2 Sub-base Testing in Transportation Network – Inspections and Testing.
  3. National Association of Australia State Road Authorities (NAASRA) roughness measurements are not required.

Definitions in this section

Approved drawings