Composite Deck to hang 500 pound point load 6

[aquacata]

In my project, MEP wanted to hang their stuff from the composite deck (3" concrete over 3" deck) using Hilti anchors, cast-in-place and/or post installed. The deck will be drilled a hole so the anchor get into the slab concrete above 3/4" or more. The maximum point load reached 500 lbs. I am not sure if it is acceptable. Hilti does have a table for their anchor capacity. But I don't know if I can use that. Vulcraft don't have too much information on that. Does anybody have an experience on this? Can yon please give me some advice? Thank you very much!

 

[msquared48]

Unfortunately, they will probably want to do this on the deck rib where the slab is thickest and also any extra primary resteel.

I would insist on cast in place, not afterset.

Mike McCann
MMC Engineering

 

[steellion]

If it must be done, insist on cast-in-place anchors as Mike said and ensure there is adequate reinforcement in this area. But I would recommend hanging from the beams instead if at all possible.

 

[hokie66]

Most of the form deck used in Australia has dovetail ribs and purpose designed hangers for the mechanical stuff and ceilings. Don't you have this type deck?

 

[MiketheEngineer]

If you have a ton of these to install - there is a company that sells a stud welder with 1/2'' - 3/4'' female sockets. Might be a thought??

 

[Gumpmaster]

Try the Simpson Blue Banger Hanger metal deck insert. They have tested capacities (~800 pounds for installation in the low flute). Seems to be just what you're looking for.

They also have a nifty graduated thread so that a single insert fits 3 different size threaded rods.

 

[wannabeSE]

I won't debate best practices. But, expansion anchors with ESR reports are frequently installed in the bottom of composite decks in California (with special inspection and testing where required). I am suprised all of the comments here are against post installed anchors. Are there any reports showing properly installed anchors failing?