Examples of concrete form that should use ignore depth
The following are examples of when design sections should ignore part of the concrete cross-section.
Example 1
A two-way slab thickening that the building code deems does not comply as a drop panel. That is, a drop cap. You should ignore the incremental thickness of the drop cap below the slab. RAM Concept then only uses the drop cap for punching checks.
Example 2
A beam or slab that supports an upstand that is not an effective part of the concrete section. You should enter an appropriate Top Ignore Depth value.
Example 3
A beam or slab that deepens abruptly and the full depth of the concrete cannot be mobilized for flexure. You should enter an appropriate Bottom Ignore Depth value.
The following figure shows bending moments in a slab perpendicular to a beam. For such an arrangement you need to decide if the slab should be designed for the bending moment at the face of the beam, or within the beam.
If the slab is to be designed for the bending moment at the face of beam, then it is a matter of locating a design section within the slab depth.
If the slab is to be designed for the bending moment within the beam then you should consider the actual depth that can be mobilized for bending.
