Wall Footing Connection - Rebar or no rebar between slab and footing?

[MidwestSE]

Hey folks!

Scenario: wood stud wall sits on edge of a slab, that slab edge is thickened to 8" and sits directly on the wall footing. The anchor bolts for the wall go into the slab only. There is no rebar between the wall footings and the slab that the wood wall above is sitting on. The picture of the detail is attached. Low seismic region.

Does anybody do it like that regularly?

I can't find anywhere in the code that says rebar is needed across the interface (assume for the sake of the question there's no net tension), but I always detail dowels. Am I spec'ing a bunch of rebar that's not needed? It seems strange to me to not have at least a nominal dowel at a generous spacing.

Also, if anyone has any comments on anchor bolts with a 7" embed in an 8" slab, please share too.

Thanks!

 

[phamENG]

What loads do you have there? You say 'assume no net tension' which is hard for me being on the coast, but okay. You'll still have shear at the base - is friction between the slab and the footing enough to transfer the shear? Or is the shear resisted by the slab? (I doubt that, since you're only use welded wire in what I assume is essentially a non-structural slab on grade.)

Most houses don't have it, and they do just fine...except the ones that are loaded to design level loads and you get the lovely pictures in all the FEMA reports.

 

[MidwestSE]

I'm doing a peer review on a project and this is one of the few big ticket items I came across. Everything else is super clear, black and white with regards to being allowed per code and meets design rules (strength/etc), but this was the one gray area where I wasn't aware of any code provision that would expressly prevent someone from doing it (if the loads were in fact small enough that there was no net tension across the joint).

For the record, there is net uplift across the joint (60' span wood trusses...)

Thanks for confirming my thoughts, pham

 

[Lomarandil]

About the 7" anchors in 8" slab, note that the most recent editions of ACI 318 Ch. 17 include some reduction factors for anchors approaching the thickness of the concrete. Assuming those are applied, I'm not opposed.

 

[phamENG]

So for a typical house this detail is okay - the dowels across the joint are limited to seismic regions in the IRC. But for an engineered structure...it's all about the loads. If no net tension and shear is low enough to be resisted by friction, sure. But I'd be looking close at that and insist on a detailed summary of the EOR's decision making process there. I prefer positive connections anywhere it doesn't actually harm the structure to have them.

(60' trusses is not what I would call a "typical house")

 

[MidwestSE]

no, this is for a commercial building