Composite Steel Deck Interface With Concrete

[Corey7320]

I was wondering if there are published values for the interface/bond strength between composite steel deck and the concrete. I have looked through USD and Vulcraft books and can't find a value.

 

[jike]

You most likely have to go back to the research testing that was done for the particular deck.

 

[kelowna]

I know very little about the subject, but I thought that on composite design you ignored the bond strength and assumed that the force was transmitted through the shear connectors.

 

[jike]

I believe the question has to do with composite deck and not composite beams.

 

[JAE]

Corey7320, if you contact Dr. Max Porter at Iowa State University, they may be able to get you some of this data...they have done quite a bit of extensive research on composite deck / concrete bond.

http://www.biorenew.iastate.edu/who-we-are/people-and-offices/directory/max-porter.html

 

[Corey7320]

Sounds like its not readily avaible data. Thanks JAE i will try your contact. One idea i had was that it could be calculated roughly from the load and span data given for a particular deck and concrete thickness. From their allowable load and span you have an allowable moment, and you know the couple geometry and therefore can get the tension force in the deck which should be similar to the bond/interface force. Is this logic flawed?

 

[JAE]

The primary mode of failure for composite decks is almost always shear-bond failure between the deck and concrete.

The stress induced on that interface is a horizontal shear (similar to the VQ/I calculation) but the problem is the deck is not uniformly located relative to the deck/concrete section neutral axis so the stress varies depending on the deck profile.

I seem to remember that there were design formulations for this shear-bond capacity that had been developed. I'll see if I can find some of them in my old notes.

 

[271828]

I know of at least one new composite slab design that uses deck with no embossments whatsoever. I haven't went looking for the research, but I'm sure the concrete-deck bond strength must be very substantial.

 

[jike]

If I remember correctly the keystone shaped deck by Epic Metals is the kind that provides bond without nibs. I know that Epic has changed there market focus and now produces only speciality decks.