minimum thickness of composite metal deck

[jeremiahcole]

Does anyone know what the minimum thickness of composite metal deck is or where that might be found? The vulcraft catalog doesn't give values for slab thickness above flutes less than 2" (for 1 1/5" deck) and I don't know the reason for this. As might be expected contractor has poured floors w/ less thickness than specified and trying to work out course of action to take.

 

[JAE]

I would think that thicknesses smaller than that shown in the published catalogs are not given due to a lack of experimental testing with smaller thicknesses.

Most composite decks fail first in shear-bond where the attachment between the deck and concrete fails. For a thin slab, you would get higher warping deformations in the concrete that would make for an earlier separation. Also, the thinner deck would give you problems with potential concrete crushing prior to a more desireable yield of the deck.

You might try Iowa State University as they have done some composite deck testing over the years for SDI or other clients.

 

[Taro]

Also, if you are using the slab as the flange for composite beams, the AISC specifications require a minimum 2" concrete thickness above the deck.

 

[jeremiahcole]

Jae, thanks for the direction, I'm looking into ISU. Also the info on what happens to a thin slab is good, now I just need some research quantifying it.

Taro, good tip, but the slab is on joists and not on beams and it is only composite in itself, not in its interaction with other structural members.

Thanks guys.