Partial vs. Full Composite Steel Construction
Partial vs. Full Composite Steel Construction
(OP)
From the Salmon and Johnson 4th edition steel book, it appears to me that, basically, a fully composite steel beam has a sufficient horizontal shear capacity from its shear studs between the point of zero moment and max moment to pick up the ENTIRE compressive force component of the couple @ max moment, while a partially composite steel beam has enough studs to only pick up a PORTION of this compressive force.
So.....my question is, why would you ever go with partially composite instead of fully composite? To save # of studs? It just seems inefficient, because then your beam size and slab thickness may be bigger if you go partial instead of fully composite...
Thanks.
So.....my question is, why would you ever go with partially composite instead of fully composite? To save # of studs? It just seems inefficient, because then your beam size and slab thickness may be bigger if you go partial instead of fully composite...
Thanks.






RE: Partial vs. Full Composite Steel Construction
The slab thickness is determined by the span and gravity loading of the slab, not by the composite beam section. The beam size for partial composite is generally the same as you would use for full composite, it just has less studs.
I hope this helps!
RE: Partial vs. Full Composite Steel Construction
Just like non-composite beams, long span composite members may be controlled by deflection criteria and not the percent composite action.
Typical range of composite I've seen is 25% to 80%.
RE: Partial vs. Full Composite Steel Construction
RE: Partial vs. Full Composite Steel Construction
Another consideration is that you are typically welding the deck at each flute anyway so you might as well use the labor to shoot a stud in.
RE: Partial vs. Full Composite Steel Construction
Finally, can you tell me what page in the code that 25% minimum is written about? Thanks.
RE: Partial vs. Full Composite Steel Construction
RE: Partial vs. Full Composite Steel Construction