Dowels from CMU wall to slab
Dowels from CMU wall to slab
(OP)
I'm performing a plan review.
Example: 8" slab w/#3 bars @ 18" oc ea way & #4 dowels (from CMU wall) @ 24" oc. (obviously different spacing)
Does this fly?
I've typically always required/designed my slab steel and dowels to the same spacing for lapping together.
I've always had the impression that dowels from CMU wall to slab were for out of plane forces, thus lapping to slab steel instead of relying on development length.
Example: 8" slab w/#3 bars @ 18" oc ea way & #4 dowels (from CMU wall) @ 24" oc. (obviously different spacing)
Does this fly?
I've typically always required/designed my slab steel and dowels to the same spacing for lapping together.
I've always had the impression that dowels from CMU wall to slab were for out of plane forces, thus lapping to slab steel instead of relying on development length.






RE: Dowels from CMU wall to slab
You need to find out if these dowels are doing anything structurally. Are they intended to limit slab movement only, are they providing a horizontal support point for the masonry wall...
You should be able to tell from the EOR's calcs what these dowels are intended for.
RE: Dowels from CMU wall to slab
RE: Dowels from CMU wall to slab
However, if no moment is needed, the only design consideration would be shear in nature, and this has nothing to do with the slab steel spacing.
Look to the EOR's calculations for the wall to determine what to do.
Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask
RE: Dowels from CMU wall to slab
Thanks for the remarks.
RE: Dowels from CMU wall to slab
RE: Dowels from CMU wall to slab
The bars don't have to be syncronised for spacing, but it is better and to achieve the same strength, the bars should be a tad longer than usual. Is it possible to construct the CMU wall with a wider block underneath the slab and support the slab on it?
Dik
RE: Dowels from CMU wall to slab
My thoughts are that the dowels are for out of plane forces, so in this case the 24" length is for development into the slab with no lapping to slab steel.
The provided calculations are supposed to be 100%, but I would rate them at 50%. Easy to make assumptions when information is lacking.
I'm waiting for a response from EOR regarding dowel design. It will probably be a few weeks before I get a response.
I appreciate all the input.
RE: Dowels from CMU wall to slab
#4 @ 24" is shy as well. You need a bare minimum of #4 @ 12"