The ULS Design Functions spreadsheet (last posted here) has been updated to the new Australian Standard for concrete structures; AS 3600-2018. The new version can be downloaded from:
Note that the biaxial version included in the download zip file is not yet updated for the new code.
The interaction diagrams below compare the new code with results from the previous version, which generates the same results as the 2017 version of the bridge code (AS 5100):
With 32 MPa concrete the new code generates higher results where bending controls (because the reduction factor is increased from 0.8 to 0.85), but where compression controls the capacity is reduced, if the reduction factor of 0.6 is applied.
Under some conditions the new code allows the reduction factor for compression to be increased to 0.65. The higher reduction factor is applied in conjunction with the 100 MPa concrete in the screen shot below (click image for full size view):
In this case the new code gives significantly higher results over the full range of axial loads:
The new version also has a number of other recent updates as shown below: