Published: 14 February 2020 | Category: Technical advice note | Audiences: Road traffic engineers & consultants, Roading contractors
This note is to advise that NZ Transport Agency (NZTA) Specification T19:2020, Procedures for design and indirect tensile strength testing of modified and bound pavement materials, has been released for general use and is available on the Transport Agency’s website for download.
This note is to advise that NZ Transport Agency (NZTA) Specification T19:2020, Procedures for design and indirect tensile strength testing of modified and bound pavement materials, has been released for general use and is available on the Transport Agency’s website for download.
The new specification is available straight away for new contracts and can be used, by agreement, in existing contracts.
NZTA Specification T19:2020, and its accompanying explanatory Notes document, is a new testing specification for anyone building bound and/or modified pavements.
It has been developed to fill a gap recognised by pavement practitioners and by their feedback via the National Pavement Technical Group (NPTG).
The NPTG is a grouping of industry (Contractors, Consultants and local and central government Clients) pavement design specialists, along with representatives from the Aggregate and Quarry Association (AQA), the Civil Engineering Testing Association New Zealand (CETANZ), Civil Contractors NZ (CCNZ) and the Association of Consulting Engineers NZ (ACENZ).
What was recognised was that practitioners designing modified pavements were having to reinvent the wheel each time with no assurance of an optimum outcome.
Given that the industry will have to consider preservation of resources to a much greater degree in future, this is a technique likely to have greater application and therefore is warranted to have better documentation.
Hence this document is intended to provide a standardised procedure to assist a pavement designer in determining the optimum type and quantity of binders for stabilising.
The new specification and notes can be found at:
https://www.nzta.govt.nz/resources/procedures-for-design
The new specification should be used to replace individual project specific requirements that might currently be being used.
It is expected that it could be applied to any pavement works, if desired, by any road controlling authority.
It is intended that practitioners apply the specification and do the testing thoroughly to assure themselves that it delivers the quality of outcome required.
The NTPG is interested in getting feedback on the ease of application and the results of applying the methodology. Feedback can be provided via the e-mail address below. The feedback will be used to evaluate performance and consider future improvements required.
We intend to let practitioners know about the release of the final specification by:
Specification T19:2020 can be implemented immediately for use with new designs, and on existing contracts by negotiation, where required.
Most contracts specifying modified and bound materials are likely to be using the available draft of T19 already.
The draft can be replaced by the final specification and/or the final document should be used for any future works.
Author: Waka Kotahi NZ Transport Agency
Published: January 2020
Version: 1
Found at: https://www.nzta.govt.nz/resources/procedures-for-design
To submit documents or if you have any questions or feedback, please contact the Technical Services team at pavements@nzta.govt.nz
[signed]
David Darwin - Chair, Ratification Group
Vanessa Browne - Delegated Approver
