Existing metal deck supporting concrete

[bnickeson]

I'm looking into an existing school built around 1966 that has a concrete-on-metal-deck roof with a deck profile I've never seen before. I have to think it's composite metal deck as there is only negative rebar in the slab. The deck is indicated as 4 1/2" deep, and is called out as 4 1/2D 16D-18, 4 1/2D 18D-20, or 4 1/2D 14D(AC) which is apparently acoustical decking. I can't find any information on these. I have an old Robertson roof deck catalog that has similar naming conventions for its deck, but nothing in that catalog matches this profile. Does anyone have a resource on this particular deck type?

Thanks.

 

[JAE]

Don't think this matches either but take a peek: https://www.cordeck.com/wp-content/...ertson-Aftermarket-Metal-Deck-Information.pdf