To model filigree slabs in PRE-Stress there needs to be temporary supports during the Erection-phase since the slab can't carry the load of the topping concrete by itself.
This calls for adding temporary supports. If supports are not added then the deflection in this phase will be really big, causing big stresses in the following combinations, making it impossible to get a working slab.
This guide will go through how to add them.
Apply the wet topping in the Erection-phase.
Be sure to include the topping dead load (default: GT) on the slab
Go to Input geometry and select Erection.
Under Input > Geometry, select Unsupported joints.
Add the joints as a distance from Joint 1 or Joint 2 (endpoints of the element)
Set the support as checked in y-direction (vertical support)
The beam/slab now has several supports along the length in the Erection phase only:
Deflections with the supports:
Same slab without the supports during construction, i.e. done the wrong way: