RC T-Beam flange connected 1

[WARose]

I have a existing (precast) reinforced concrete beam that was connected to a girder by placing it on a ledge. (There is a formed shear key as well.) Apparently, after the placement, a floor was poured.....that essentially made it a t-beam. The slab is tied to the girder by top & bottom reinforcement.

By my model, some shear is attempting to transfer by shear stress in the slab (as you would expect) to the girder. But the "web"/precast part can take all the shear. So I am wondering: can I ignore the shear from the slab attempting to "help" in the transfer? My gut instinct is: "no". Go with the model. By any shear flow calculation, you'd get some shear.....no doubt. But I wonder if there is a loophole in code somewhere I am forgetting.

In case you are wondering about sizes: the precast beam is 4'x2', and the slab is 1' thick. Thanks.

 

[KootK]

So I am wondering: can I ignore the shear from the slab attempting to "help" in the transfer?

Hell yes. For no other reason than that everybody does this all the time and we'd go nuts if we were to try to track things down to such a granular level of detail. Yes, you'd probably crack your slab in shear near the beam before fully engaging your beam stirrups under ULS conditions. Risk it.

 

[WARose]

As always, thanks for the feedback Kootk.

 

[MIStructE_IRE]

For what its worth, Koot’s approach is no different this side of the pond.