Hollow cores settings can be edited in the Revit family. If there are no available predefined families in your company folder, then use standard hollow core families from the IMPACT standard, which can be found in …\IMPACT15\Standard\1101\1101\Revit\elements\hollowcore. 

General

The General tab includes settings for the main geometry of the hollow core section such as height and width. 

Tolerance : Notice that the main width of the hollow core includes the tolerance on both sides of the element. For example, a gap of 4 mm between hollow cores, would require a tolerance of 2 mm on each side of the hollow core slab.
Diff. bottom top is a setting used for calculating the top geometry of the slab, which is often shown in the shop drawings. 

The hollow core section can also be connected to a Production line. If there are predefined production lines, choose one from the falling menu.

Cores

This tab previews the cores that have been defined for the hollow core section. Cores are numbered in the table and the user has the possibility to preview their placement, geometry and area in a table. The table is only for viewing already made core settings.

Cutting

Rules for cutting the slab are specified in the Cutting tab. Rules for cutting zones must be defined in advance, in order to arrange a proper cutting of the slab, without cutting though a web or a strand location. The user can choose between three cutting methods: Single sided left, Single sided right or Symmetrical. Cutting zones can be specified in the table to the right by using numeric values. Once defined in the table, the cutting zones will be viewed in green color in the hollow core section picture. Cutting zones can be added or deleted from the section by, relatively, New and Delete button in the lowest right corner.  

Strands

Strands tab includes settings for the grouping and the location of the strands in the hollow core section.  The user can create strand groups and edit their settings in the Strand groups section to the left. The placement and the group belonging of each strand in the hollow core section can be edited in Strand positions table.  Strands can be added, deleted or modified by the user and the changes will be viewed in the hollow core section picture. Choose a strand group in the falling menu, containing all created strand groups, viewed to the left. 

Strand Patterns

Strand Patterns tab contains information about all available strand patterns for the hollow core section. The user can add new strand patterns or modify the existing in the Strand pattern table. There must be always one strand pattern set as default, which is used when drawing the hollow core slab. The user must define, which strands should be included in the strand patterns by checking them out in the Strand positions table.

Calculations

Recess

Recess tab gives a possibility to create vertical and horizontal circular recesses in the hollow core slabs. The user must define the recess type and then type diameter for the circular recess. The sketch of the hollow core section will change with the editing of the recess settings.

Recess Edge 

In Recess edge the user can define rectangular and circular recess or the edge of the hollow core section. There are two available type of recess: Rectangular and Rectangular and circular.  After defining the recess values the hollow core sketch will change according to the settings.  

Hangers

In Hangers, the user can create hanger details. Click on New to open a new dialog window, where the geometry settings as well as settings for the placement of the hanger can be made.  The user can change CIM family, decide core filling and edit the recess in the Hollow Core slabs. The Hollow Core sketch will change while the different parameters are set