one way slabs cast mono w/ beams

[struct_eeyore]

Hi all,

Second image shows a beam supporting a slab, which then shares the intersecting portion with the beam. I am curious if any of you check the interaction stresses when designing something like this. The only thing that resembles an answer that I found in ACI is in R7.6.4.2 (which relates to post tensioned/prestressed slabs) which calls for generating 100psi min compressive stresses across the intersection (roughly). Is there a way to replicate this with a standard CIP slab? Do I need to check my shear friction? All thoughts welcome. EDIT: title spelling error

 

[KootK]

- The detail to the right is typcial and what I would do.

- If, by interaction stresses, you mean bi-axial compression in the concrete, then, no, nobody checks that. It's probably beneficial by way of confinement etc anyways.

- Technically you should check shear friction. That said, with the right side detail and small diameter stirrups, I no longer bother. Two reasons for that:

1) I've checked a few and, baring unusual loading situations, it's never a problem.
2) You can count the same stirrups for shear and shear friction. In this sense, the problem nearly becomes self satisfying.
3) I've seen some literature on two pour bridge girders that suggests that you're probably fine for interface shear even with no stirrups at all crossing.

 

[BAretired]

The first image shows the top bars depressed below the slab which is not correct for a Tee Beam. The second image shows a Tee Beam with top bars near the top where they should be. No special check is made for stress across the intersection.



BA