Concrete Behavior

You define the concrete elastic modulus in the materials window. You can choose to use code equation 8.6.2.2 or a specified value.

When you directly specify values, there must be two elastic modulus values:

When the CSA code equation is selected the following values are used:

E_{c i} = [3, 300 \sqrt{f_{c i}} + 6, 900] {(\frac{γ_{c}}{2, 300})}^{1.5}

E_{c} = [3, 300 \sqrt{f_{c}} + 6, 900] {(\frac{γ_{c}}{2, 300})}^{1.5}

where

f_ci	=	cylinder strength at stressing (MPa)
f_c	=	28 day cylinder strength (MPa)
γ_c	=	density of concrete (kg/m³)

For calculations based on the gross section, concrete is assumed to be a perfectly linear-elastic material with no stress or strain limits.

See Concrete Stress-Strain Curves for a description of the stress-strain curves used in a detailed cross section analysis.

The strength stress-strain curves are truncated at a strain of 0.0035. The other stress-strain curves have no limit strain.