CMU/Conc Vertical Wall Joint

[strucbells]

I am designing a 1 story CMU water treatment building that has partial height cast in place concrete basin walls that form part of the exterior wall. See attached rough sketch.

I am planning to provide masonry control joints as shown in the attachment. At the vertical joint between cast in place concrete and CMU below the all CMU control joint, what is typically done here? Can they cast in a CMU type preformed control joint into the concrete wall end to continue the control joint full height? Or should I provide a thin PJF material or bond breaker between the two? Do nothing?

Thanks,

 

[JoelTXCive]

I'm interested to hear what others say, but could you use dowels?

One end of the dowel could be drilled & epoxied into the concrete.

The other end could be sleeved in a plastic formsaver. Then, grout the first cell and encapsulate the formsaver.

The joint could then be caulked.

 

[haynewp]

I don't know the spans and lateral load, but I believe it will help to void any possible differential stiffness cracks by using the joint full height. I would likely just specify a PJF at that vertical interface. But I've also seen similar cases doweled with smooth bars and nothing probably ever came of it.

 

[strucbells]

CMU walls are all spanning vertically.

No support slab at the location indicated, they are open top filter basins with grating.

Out of plane loads can be handled by the CMU vertical reinforcing as this is the typical condition on the other walls not shown that run full height.

Main concern/reason for posting is dealing with any differential shrinkage and/or thermal movement between the CMU and concrete. The filter basins walls are 15" vs 8" CMU if that makes any difference.

I had been thinking more to isolate the 2 than tie them together but could see arguments for both.

 

[haynewp]

If connecting the concrete and CMU walls, why wouldn't you use smooth dowel bars anyway?