web crippling of a W-Beam encased in concrete ??

[tweedledee]

If a wide flanged beam is encased in concrete (no mesh so I cant consider it composite), do I need to check for web crippling, and web yielding for the concentrated load on the beam?

Is there any reference out there that covers this??

Thanks

 

[JAE]

I'm not aware of any reference...I would probably not consider the concrete as resisting web crippling or providing any other help if:

1. The concrete is simply unreinforced, cast fire proofing for the beam, or

2. The concrete might be removed someday for whatever reason, or

3. The beam and concrete is in any way exposed to potential moisture infiltration where rusting and spalling of the concrete might occur (I've seen this happen in buildings a lot).

I all of these cases, the concrete may not be considered structural by some future engineer or owner and the concrete removal would create a loss of capacity and safety without anyone (except for you) knowing it.

If the concrete is cast-in, integral with a slab, and reinforced, then perhaps you could then consider its benefits in regards to web crippling, LTB, etc.

 

[tweedledee]

Thanks Jae,
Thats a good answer. This is an existing building and WE have removed concrete from steel beams in other areas to investigate the existing conditions. I wouldn't like to rely on this concrete only to have someone else in 50 years remove it to investigate this connection.

Thanks

T