Inverted Steel Deck as Formwork

[sublimekid]

Hi all,

I'm looking to use one of the heavier steel floor decks as form work to support construction loads for a 254mm slab, with spans of ~2.7m.
The purpose of inverting the deck is to provide the required bottom bar spacing for the slab reinforcement.

This Link suits my application, but it would need to be installed upside-down.
I suspect there must be a difference in local buckling capacity for the inverted profile.

I've yet to find an wide bottom flute deck that can work for my application, so if anyone can point me in the right direction, that would be my first choice.

Otherwise; is it reasonable to use the table values directly? Or what needs to be considered?

 

[KootK]

Based on a comparison of the "support" and "midspan" values in the table, it appears that the deck is actually stronger when the narrow end of the ribs are in compression. So if this is simple span stuff, you should be good to go. If it's continuous, I'd think that it would be safe to prorate your capacity based on the moment capacity ratio midspan/support. They're nearly balanced so it wouldn't be much of a hit at all.

Lastly, I'd give Vicwest a call. I guarantee that they've dealt with this in the past. And temporary structures are notorious for getting folks hurt so some fact checking is probably prudent.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.

 

[sublimekid]

Excellent Reply. Thanks for the input!
Makes sense to get in touch with supplier to. Glad to know i'm not going too far off in the wrong direction.