Resources

Purpose

This note advises that Waka Kotahi NZ Transport Agency specification M01: 2020, Specification for bitumen, and its accompanying notes, has been released and is available from the Highways Information Portal on the Waka Kotahi website.

The key changes are:

• Amendments to the requirements for bitumens imported into New Zealand;
• Minor amendments to the requirements for bitumen as supplied for use in road pavements.

General information

M01 specification was last reviewed in 2011. At that time, most bitumen used in New Zealand pavements was manufactured by Refining New Zealand at their Northland refinery, from a limited range of crude oil feedstocks and using a consistent process.  Importation was permitted under M01: 2011 but imported bitumens were required to comply with the all the physical requirements listed in Tables 1 and 5 of that version of the specification.

M01 is unique to New Zealand and reflects our cool maritime climate, geology of our materials and methodology of how we construct pavement surfacings. It can be difficult to identify offshore bitumen producers who make bitumens compliant with our bespoke specification.

In 2020 Refining New Zealand announced that onshore production of bitumen would cease and all bitumens for pavements would be imported. At that time M01 was reviewed to determine if it was aligned with the new supply model. The requirement that only fully compliant bitumens could be imported was identified as a possible supply constraint. This initiated the update to M01 specification with adjustments to the rules for importation, as follows.

Changes to the specifications

As noted above the prior version of M01 required imported bitumens to comply fully with the specified requirements.  This limits the range of offshore producers that could supply into New Zealand.

The updated M01: 2020 has addressed this problem by: 

• Allowing bitumens to be imported that meet minimum standards for purity, safety and durability.  They do not necessarily have to meet all the previously specified requirements to be imported, and;
• Requiring that these imported bitumens can then be supplied, blended or otherwise processed to make bitumens fully compliant with the specified physical criteria when supplied for use on road pavements.

Some minor amendments have also been made to M01: 2020 Table 6.1 to rationalise the measurement of durability and ensure that bitumens are not blended to grade by using unsuitably volatile diluents.

Benefits

Benefits arising from this update include:

• The reduction of constraints on importation widens the range of potential offshore suppliers.  This strengthens the potential supply base and allows for competition, and;
• Retention of the specified physical criteria for bitumen from previous versions of the specification provides surety of quality and performance in road pavements.

Implementation

The updated specification is now available for use.  To aid the implementation, support and advice is available from the Waka Kotahi Principal Surfacings Engineer at pavements@nzta.govt.nz

Document review

To see if updated specification is working effectively, it is intended to undertake a review in twelve months’ time to ensure the specification has optimised the importation process.

Publication details

Document: NZTA M01: 2020 Specification for bitumen and its accompanying notes
Author: Waka Kotahi New Zealand Transport Agency
Published: February 2021
Version: M01: 2020
Found at: https://www.nzta.govt.nz/resources/roading-bitumens/

Further information

If you have any questions or feedback, please contact the Waka Kotahi Principal Surfacings Engineer, Grant Bosma at pavements@nzta.govt.nz

[signed]

David Darwin - Chair, Ratification Group

Vanessa Browne - Delegated Approver