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Slab edge from beam distance

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JStructsteel

Structural
Aug 22, 2002
1,446
Is 7.5" from CL of beam to slab edge too much? Construction wise they will have to use a bent plate for the screed angle. Some edges too will be load bearing. I hate to require a bunch of gussets.
 
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The AISC Design Guide 22 for Facade Attachments has good guidance and examples for this sort of thing.
 
Here is a detail
slab_edge_detail_baj8bc.jpg
 
That helps. What is your concern - is it with the temporary works case of the wet concrete being poured and how the edge of the concrete can be supported..?
Or is it to do with the support to the top of the bricks?

If it's the temporary works case, it's just a matter of you doing some numbers to see whether it's viable or not
7.5" is a pretty big angle, but you can get them that big. I suspect it's stiff and strong enough to weld to the top of the beam to support the concrete while wet
Then rely on concrete top steel once set to take the small cantilever loads for any walls etc at the outside edge
 
Thanks, thats what I thought. Just wasnt sure if a better way. Slab is 5" so deep enough to support the load of the wall above.
 
The steel deck on your section appears to have a very low profile. Normally, steel deck supporting a five inch slab would be a minimum of 1.5" deep. If the 5" depth is measured from the underside of steel deck to top of concrete, the effective slab is only 3.5". Is that sufficient to support the load from the wall above?
 
If the distance to the beam centerline is 7.5", then the overhang is probably 5.5" or less. Cold-formed steel edge forms are often used. ANSI/SDI C-2011 Standard for Composite Steel Floor Deck-Slabs has the following table:

Screenshot_2023-03-25_145133_ekwrym.jpg


If you have heavier loads or tighter deflection limits than the table criteria, you would typically provide a 3/16" or 1/4" thick steel bent plate.
 
Its 1.0C deck, so 4" slab.

OldDawg, thanks, perhaps I will spec those instead of angle.
 
I second using a steel bent plate and optionally some rebar. The other concern is architectural. Putting the building finishes on the slab like that makes it hard to have a thermal break for energy reasons. It'll be hard to put insulation. Also, the slab edge would need to be finished in a different material than brick. If the architect needs all that stuff and wants you to push out the finishes, I generally use WT gussets for attaching a relieving angle.
 
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