Free shrinkage strain behavior can be modeled as a load effect in reinforced concrete design and check.

Shrinkage effect is calculated as a specific rotation. The following formulas give the example of calculation for reinforced concrete slabs:

1583243586006-291.png

1583243599451-359.png

The specific normal force causing the given shrinkage value (εcs [‰]) in the concrete zone of the section is (here in X direction).

1583243603354-802.pngThe position change of centre of gravity considering reinforcement bars (here X-direction; see dashed line), where 1584536267263-190.png  and Ss is the statical moment of (here) X-directional bars around the Y axis of the calculation plane.
1583243608703-727.pngThe moment around the Y axis of the calculation plane from Nx because of the position change of centre of gravity.
1583243613435-905.pngThe specific rotation (curvature) from My for 1 meter wide section, where 1583243657849-969.png .

Definition steps

  1. Set the shrinkage strain (εcs) value at the material properties of concrete structural elements.

    1583244251192-320.png
    Figure: Shrinkage value of concrete materials
    1582804849244-917.pngShrinkage effect is taken into consideration in RC design and check of concrete elements, which have applied reinforcement.
  2. Start the 1583244327461-862.png  Load case command, and define one “+Shrinkage” type load-case with a name (such as “Shrinkage effect”). That means, the automatically calculated shrinkage effect is allowed on load-case level.

    1583244339863-490.png
    Figure: Shrinkage effect added to a load case
  3. Add the load case defined in the 2nd step to load combinations/groups depending on the later RC design.
Created by Fredrik Lagerström on 2020/04/02 17:47
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