Hi,
Why Civil 3D for creating Steel/concrete structures?
If the elements are modeled with basic autocad features then you can just link the file in Revit. If the CIvil 3D features (Feature lines, surfaces etc.) are used then you need to export from Civl 3D to Autocad DWG (Command: EXPORTTOAUTOCAD).
When creating a section of the DWG in Revit you will see the entire DWG. You can avoid this with placing the DWG in a component in-place. in this way you only see the lines from the DWG that are within the view range.
