No worries, it sounds as though we figured it out after all. That being the case, I stand by my previous responses. The rib parallel to the wall is prudent for both vertical load distribution and shear transfer. Unless exceptional care is taken in the construction of the infill between ribs, which I assume are fairly tights spaced, I would not rely on them for shear transfer. They simply do not tend to be built robustly.
I know of nothing in ACI that prescribes/proscribes any of this explicitly. But then not all sound engineering practices are codified.
I think that the important part of this is the understanding that there should be competent load transfer between floor diaphragm and wall. Whether or not the infill bits touch the wall is immaterial.
In open webbed steel joist systems, we sometimes transfer shear through joist seat rollover rather than shear lugs installed between the joists. Similarly, with your rib slab may be able to transfer shear to the wall via local weak axis bending of the ribs rather than the use of a distribution rib running parallel with the wall. If you ran the numbers and it worked, I wouldn't much care if the "non-structural" infill block between ribs was in contact with the ribs/floor. I suppose this infill bits might be exposed to a very small risk of inconsequential cracking under the application of lateral load.
I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.
