25% composite action - In existing beams?
25% composite action - In existing beams?
(OP)
I'm working on a project where we are checking an existing composite floor system for additional equipment loads. The existing infill beams are W16x26 with only 10 shear studs on them. Given 3/4" dia, weak stud the beam would be less than 25 % composite action. Adding more steel would only make this worse and the owner would like to continue using the floor system.
Questions to all:
a)25% min composite action is a standard practice and in many texts it says that composite action below 25% are not accurate. Is there anything in the code that states the 25% min rule?
b)when determing the moment capacity of the W16x26's without any additional reinforcement, would you consider the less than 25% composite action or simply design it as non-composite?
Thanks to all.
thread507-182835: Adding Studs to Existing Composite Beam
Questions to all:
a)25% min composite action is a standard practice and in many texts it says that composite action below 25% are not accurate. Is there anything in the code that states the 25% min rule?
b)when determing the moment capacity of the W16x26's without any additional reinforcement, would you consider the less than 25% composite action or simply design it as non-composite?
Thanks to all.
thread507-182835: Adding Studs to Existing Composite Beam






RE: 25% composite action - In existing beams?
RE: 25% composite action - In existing beams?
unfortunately it appears as if it's across the beam (although it doesn't specifically state that). the number of studs is noted in a box and the note says "indicates number of 3/4" dia 4" high shear studs"
even if the engineer expected that to be on each side, i can't imagine a contracter reading that note and knowing that is half the total amount required.
RE: 25% composite action - In existing beams?
RE: 25% composite action - In existing beams?
We are Virginia Tech
Go HOKIES
RE: 25% composite action - In existing beams?
Michael.
Timing has a lot to do with the outcome of a rain dance.
RE: 25% composite action - In existing beams?
RE: 25% composite action - In existing beams?
For partial composite action, the lower number of connectors may make that the difference between the actual elastic demand present and what provided is as high as to produce the failure of the connectors even at service level condition, then also failure in composite action, and less than required limit strength.