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1 (% class="wikigeneratedid" id="HShrinkageStrain" %)
2 Free shrinkage strain behavior can be modeled as a load effect in reinforced concrete design and check.
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4 Shrinkage effect is calculated as a specific rotation. The following formulas give the example of calculation for reinforced concrete slabs:
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6 (% style="width:923px" %)
7 |(% colspan="2" style="width:920px" %)(((
8 [[image:https://wiki.fem-design.strusoft.com/xwiki/wiki/femdesignwiki/download/Manuals/User%20Manual/Loads/WebHome/1583243586006-291.png||alt="1583243586006-291.png"]]
9 )))
10 |[[image:https://wiki.fem-design.strusoft.com/xwiki/wiki/femdesignwiki/download/Manuals/User%20Manual/Loads/WebHome/1583243599451-359.png||alt="1583243599451-359.png"]]|(% style="width:806px" %)(((
11 The specific normal force causing the given shrinkage value (ε,,cs,, [‰]) in the concrete zone of the section is (here in X direction).
12 )))
13 |[[image:https://wiki.fem-design.strusoft.com/xwiki/wiki/femdesignwiki/download/Manuals/User%20Manual/Loads/WebHome/1583243603354-802.png||alt="1583243603354-802.png"]]|(% style="width:806px" %)The position change of centre of gravity considering reinforcement bars (here X-direction; see dashed line), where [[image:https://wiki.fem-design.strusoft.com/xwiki/wiki/femdesignwiki/download/Manuals/User%20Manual/Loads/WebHome/1584536267263-190.png||alt="1584536267263-190.png"]] and //S,,s,,// is the statical moment of (here) X-directional bars around the Y axis of the calculation plane.
14 |[[image:https://wiki.fem-design.strusoft.com/xwiki/wiki/femdesignwiki/download/Manuals/User%20Manual/Loads/WebHome/1583243608703-727.png||alt="1583243608703-727.png"]]|(% style="width:806px" %)The moment around the Y axis of the calculation plane from //N,,x,,// because of the position change of centre of gravity.
15 |[[image:https://wiki.fem-design.strusoft.com/xwiki/wiki/femdesignwiki/download/Manuals/User%20Manual/Loads/WebHome/1583243613435-905.png||alt="1583243613435-905.png"]]|(% style="width:806px" %)The specific rotation (curvature) from //M,,y,,// for 1 meter wide section, where [[image:https://wiki.fem-design.strusoft.com/xwiki/wiki/femdesignwiki/download/Manuals/User%20Manual/Loads/WebHome/1583243657849-969.png||alt="1583243657849-969.png"]] .
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17 **Definition steps**
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19 1. Set the shrinkage strain (ε,,cs,,) value at the material properties of concrete structural elements.
20 \\[[image:https://wiki.fem-design.strusoft.com/xwiki/wiki/femdesignwiki/download/Manuals/User%20Manual/Loads/WebHome/1583244251192-320.png||alt="1583244251192-320.png"]]
21 Figure: Shrinkage value of concrete materials(((
22 (% style="width:669px" %)
23 |(% style="width:100px" %)[[image:https://wiki.fem-design.strusoft.com/xwiki/wiki/femdesignwiki/download/Manuals/User%20Manual/Loads/WebHome/1582804849244-917.png||alt="1582804849244-917.png"]]|(% style="width:566px" %)Shrinkage effect is taken into consideration in RC design and check of concrete elements, which have **applied reinforcement**.
24 )))
25 1. Start the [[image:https://wiki.fem-design.strusoft.com/xwiki/wiki/femdesignwiki/download/Manuals/User%20Manual/Loads/WebHome/1583244327461-862.png||alt="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.
26 \\[[image:https://wiki.fem-design.strusoft.com/xwiki/wiki/femdesignwiki/download/Manuals/User%20Manual/Loads/WebHome/1583244339863-490.png||alt="1583244339863-490.png"]]
27 Figure: Shrinkage effect added to a load case
28 1. Add the load case defined in the 2^^nd^^ step to load combinations/groups depending on the later RC design.
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