The first joint New Zealand and Australian composite design standard DR AS/NZS 2327 has recently been published for public comment.

The public comment period will continue until 24 January 2017 and electronic copies of the draft standard can be freely downloaded from here.

This revision incorporates a number of technical and editorial changes, as follows:

  1. Changes to the strength of concrete, raising the maximum compressive cylinder strength to 100 MPa.
  2. Changes to the yield strength of steel, raising the maximum tensile yield strength to 690 MPa.
  3. Provisions for the design of composite slabs using profiled steel sheeting.
  4. Provisions for the design of composite beams.
  5. Provisions for the design of composite columns.
  6. Provisions for the design of composite joints
  7. Provisions for system behaviour floor design.
  8. Provisions for fire design.
  9. Provisions for earthquake design.

Work on the development of this new standard commenced in 2012 and, once published in its final form, it is intended that AS/NZS 2327 will replace NZS 3404, Section 13, as well as some parts of Section 11 and 12. It is also hoped that this work may pave the way for bringing together the existing AS 4100 (AS 4100 1998) and NZS 3404.1 (NZS 3404.1 1997) into a joint Australian and New Zealand steel structures standard.

As well as providing rules for composite beams which are similar to NZS 3404.1, Section 13, AS/NZS 2327 gives specific design provisions for: composite columns; composite slabs; composite joints; system behaviour for floor design (including human-induced vibrations); fire resistance; seismic performance; and beams with web-openings.

Owing to the fact that higher strength materials are permitted (specified strength of concrete f’c ≤ 100 MPa and nominal yield strength of structural steel fy ≤ 690 MPa), meant that the scope of AS/NZS 2327 was much wider than other international composite design standards; as a consequence of this, rigorous structural reliability analyses according to AS 5104 and ISO 2394 were undertaken by NZ and Australian Committee members to ensure that new provisions delivered the target margins of safety.

This collaborative effort between NZ and Australia has also led to rules that go beyond international standards; for example, in fire design, where the slab panel methodology (which permits some beams within a floor to be left unprotected), has been formalised. It is strongly encouraged that NZ users review DR AS/NZS 2327 and provide comment as, in some cases, there are significant departures from current practice.

Please note that when submitting comments on draft Joint standards, these must be submitted to Standards Australia. To do this, please use this link here.

Note: any emails or forms sent to Standards Australia by fax or mail will not be considered by the Committee when it reviews the Public Comment received.