This Standard incorporates Amendment No. 1 (May 2002) and Amendment No. 2 (October 2004).  The  changes  required  by  the  Amendment  are  indicated  in  the  text  by  a  marginal bar and amendment number against the clause, note, table, figure or part thereof affected.

Objective of the Standard

The  principal  objective  of  the  Standard  is  to  provide  users  with  nationally  acceptable  
unified  rules  for  the  design  and  detailing  of  concrete  structures  and  elements,  with  or  
without  steel  reinforcement  or  prestressing  tendons,  based  on  the  principles  of  structural  
engineering mechanics. The secondary objective is to provide performance criteria against which  the  finished  structure  can  be  assessed  for  compliance  with  the  relevant  design  
requirements.

Background to the Third Edition

Amendment No. 1 to the 1994 edition of the Standard was issued in August 1996 to take
account of the low ductility of wire to AS 1303 and mesh to AS 1304. It also incorporated
improvements based on user experience in implementing AS 3600.

Following  a  five-year  review,  further  amendments  to  the  Standard  were  approved  by  the  
Concrete Structures Committee in August 1999. These amendments take account of more
recent revisions of key materials Standards, and incorporate additional improvements to the
clarity and intent of particular requirements, based on user comments.

In view of the number and extent of the amendments to AS 3600 now involved, the SAI
Concrete Structures Committee recommended that, rather than issuing further ‘green slip’
amendments, a Third Edition of AS 3600 be published which incorporated all published and
approved amendments, Amendment 1 and 2.

Differences between the Second and Third editions of AS 3600

As noted in the opening paragraphs of the Preface, this Edition incorporates Amendment
No. 1 of August 1996 and amendments approved in August 1999.

Areas  of  major change covered in Amendment 2,  which have been incorporated into this
edition, are as follows:

1: Introduction  of  500 MPa  reinforcing  steel  with  AS/NZS 4671  covering  the  
specification  for  the  new  grade  of  reinforcing  steel.  The  carbon  equivalent  of  the  
reinforcement has been held  to  a level  so that current practices for site  welding  of
reinforcement including ‘locational tack welding’ can continue to be used.

2: Increase in the maximum concrete compressive strength to 65 MPa.

3: Consistency of references and information within AS 1379—Specification and supply
of concrete, including a change to the basic shrinkage strain value to reflect normal
class concrete.

4: Fire-resistance  periods  for  the  structural  adequacy  for  columns  has  been  revised  
following research by  BRANZ, and  allowances for  chases and recesses in  concrete
walls  have  been  included  and  are  consistent  with  those  in  AS 3700,  Masonry
structures.

5: Linear  elastic  analysis  requirements  have  been  reviewed  with  consideration  of  
propping, effective stiffness, secondary effects and moment redistribution.
AS 3600—2001.

6: Beam  strength  and  serviceability  design  requirements  have  been  significantly  
reviewed  with  changes  to  the  minimum  strength  requirements,  deflection  by  
simplified  calculation,  the  deemed  to  comply  span-to-depth  ratios,  crack  control  
provisions and end anchorage of fitments among others. The maximum transvese bar
spacing have also been increased.

7: Changes  have  been  made  to  the  rules  for  flexural  crack  control  of  slabs,  including  
reduction of the maximum transverse bar spacing.

8: Development  length  and  splicing  of  reinforcement  has  been  revisited  and  include  
amendments to the deemed to comply lengths and the size of bars permitted in tension
and compression lapped splices. Rules for welded and mechanical splices have been
removed and new rules are under development.

9: Material requirements have been updated with reference to the current AS 1379 and
the new reinforcing steels to AS/NZS 4671.

10: Section 20  has  been  deleted  in  its  entirety,  with  all  aspects  of  the  testing  and  
assessment of concrete referred to AS 1379.

11: Section 21, on the testing of members and structures, has been completely redrafted
and relabelled as Appendix B.

The Committee is in the process of a major revision of AS 3600, which includes the areas
of high-strength concrete, bond and anchorage requirements and application of mechanical
and welded splices.

The  terms  ‘normative’  and  ‘informative’  have  been  used  in  this  Standard  to  define  the  
application of the appendix to which they apply. A ‘normative’ appendix is an integral part
of a Standard, whereas an ‘informative’ appendix is only for information and guidance.

First published in part as AS CA2-1934. AS A26 first published 1934. AS CA2 redated 1937. MP 13 first published 1957. AS CA2-1937 and AS A26-1934 revised, amalgamated and redesignated AS CA2-1958. Third edition 1963. MP 13-1957 revised and redesignated AS CA35-1963. Second edition 1973. Fourth edition AS CA2-1973. AS CA2-1973 revised and redesignated AS 1480-1974. AS CA35-1973 revised and redesignated AS 1481-1974. Second edition AS 1481-1978. Second edition AS 1480-1982. AS 1480-1982 and AS 1481-1978 revised, amalgamated and redesignated AS 3600-1988.