Be careful using the new AS 3600 for column design; there is a typo in the equation for gamma (Cl 8.1.3.2(b)(ii))!
In the last public draft it was:
1.05 - 0.007f'c (>=0.67, <=0.85)
In the published code this had changed to:
1.00 - 0.003f'c (>=0.67, <=0.85)
which is the same as the equation for alpha2
It is my understanding that this is an error, rather than an intentional change.
The draft version gives results that are effectively the same as the previous code up to 50 MPa, and a little more conservative at 65 MPa. The published code is unconservative from 40 MPa up.
I have some spreadsheets for combined bending and axial load to AS3600 on my blog, but I won't be updating them until the code is sorted out (and goodness knows when that will be).
