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Purpose

This technical advice note outlines interim requirements for the use of mechanical reinforcement couplers and anchors, subsequent to the publication of the Bridge manual 3rd edition amendment 3.

With the publication of amendment 3 in October 2018, Technical advice note TAN #17-14 Bridge manual amendment - interim advice - mechanical reinforcement couplers and anchorages was superseded and withdrawn.

With the publication of the Bridge manual amendment 4 in May 2022, this Technical advice note #19-07 is no longer required. However, the requirements of this TAN shall remain in place for a period of six months (ie until the end of November 2022) as alternative means of compliance to the revised provisions of the Bridge manual.

General information

Amendment 3 to the 3rd edition of the Bridge manual introduced a number of changes to the requirements for mechanical couplers and anchors as detailed in clause 4.2.1(f). Primarily the Bridge manual requirements were brought closer to those of NZS 3101:2006 (incorporating amendment 3) whilst requirements for the demonstration of conformity for both couplers and anchors by one of the two methods allowed by ISO 15835‑1:2009, ie system certification or batch verification were introduced.

It is acknowledged that ISO 15835:2018 parts 1 to 3 have been published. This technical advice note however refers to ISO 15835:2009 parts 1 and 2 in line with the Bridge manual 3rd edition amendment 3 and NZS 3101:2006 (incorporating amendment 3).

Requirements

It is acknowledged that it will take some time for the manufacturers and suppliers of mechanical couplers and anchors to be able to demonstrate full compliance with the updated clause 4.2.1(f) via the system certification route, and that the batch verification requirements are relatively onerous. In the interim, for a period of six months from the publication of this technical advice note (ie until the end of January 2020), mechanical couplers and anchors may be used on NZ Transport Agency projects subject to their use meeting the conditions specified herein.

• Any coupler or anchor system together with associated reinforcement that can demonstrate full compliance with the requirements of Bridge manual clause 4.2.1(f) is acceptable.

Otherwise:

• Coupler and anchor systems together with the associated reinforcement bar must be shown or have been shown by qualification testing in accordance with ISO 15835‑1:2009 annex A or ISO 15698‑1:2012 (as appropriate), or otherwise acceptable to the Transport Agency, to meet all the applicable requirements of NZS 3101:2006 incorporating amendment 3.
• Qualification testing must be carried out separately for each source of reinforcing bar intended to be used with the coupler or anchor system.
• Each batch of couplers or anchors together with associated rebar shall be tested in accordance with the factory production control requirements of ISO 15835‑1:2009 annex A or ISO 15698‑1:2012 (as appropriate) to confirm that the requirements of NZS 3101:2006 are met. The rate of testing shall be one sample per batch of up to 500 units. Test certificates shall be supplied with each delivery to site, together with manufacturing quality assurance certificates for the separate couplers or anchorages and reinforcing steel.
• Test methods for both qualification testing and factory production control testing shall be in accordance with ISO 15835‑2:2009 or ISO 15698‑2:2012 as appropriate.
• Brittle fracture resistance shall be demonstrated in accordance with the requirements of Bridge manual clause 4.2.1(f)(iii).

Effective start and end dates

The requirements of this technical advice note shall apply with immediate effect and shall remain in place for a period of six months (ie until the end of January 2020) unless they are otherwise revoked, either by issue of a further technical advice note or of a relevant revision to the Bridge manual.

Note that for projects tendered prior to the publication of amendment 3 of the Bridge manual, the requirements for couplers and anchors that applied when the project was tendered shall apply unless agreed otherwise with the Transport Agency’s Lead Advisor Structures, whereupon the requirements of this technical advice note shall apply instead.

Further information

If you have any questions or feedback, please contact the Technical Services Structures team at bridgemanual@nzta.govt.nz

David Darwin                 Vanessa Browne