Concrete · Columns & walls

Column biaxial bending (AS 3600) calculator

Load-contour check (Mx*/φMux)^αn + (My*/φMuy)^αn ≤ 1 for a rectangular column, with the exponent αn derived from the axial load.

Standard: AS 3600-2018 Cl 10.6.4 load contour

Inputs in the worked example

The live calculator starts with these values; change any of them and every result, check and diagram updates instantly.

Diagram for the worked example

Nuo = α1 f′c (Ag − As) + fsy As
αn limited to 1–2
φMux and φMuy come from the uniaxial interaction diagrams at N* (use the column tool)

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For preliminary design and education. Check every result against the current standard and your own engineering judgement before use.