Integrity Reinforcing Below Column for Transfer Slab (Canadian Code) 2

[KootK]

It seems to me that, where a concrete column is transferred out at transfer slab, there should be integrity steel beneath the column just like at regular slab/column joints. And for the same reason: a fail safe in case of a punching shear failure. In fact, I feel a greater need for integrity reinforcing at transfer slabs because the stakes are so much higher.

Normally, integrity steel is placed at the bottom of slabs. There's a sketch and some commentary in CSA that explains why. My thinking is that integrity steel beneath a transferred column should actually be at the top of the transfer slab. After all, a transferred column at a transfer slab looks much like an upside down, heavily loaded, roof slab.

So my questions are two fold:

1) Are others including integrity reinforcing beneath transferred columns?

2) If you are including integrity steel, are you placing it at the top of the slabs?

I guess whether or not integrity steel could actually deal with the loads imposed by a transferred column is another story. Unfortunately, increasing slab depth doesn't improve matters for integrity steel.

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.

 

[hokie66]

There is always going to be a lot of steel in the bottom at a transferred column. I agree that integrity steel should be provided in the top, but don't know how much, and would consider this in each case. Punching shear is only one reason for integrity steel.

 

[dcarr82775]

It makes sense to provide it, and provide it in the top. I have never had the pleasure of a transfer slab myself.

 

[KootK]

Thank you for your responses gentlemen. I'm hoping to get a few more. Perhaps adding some graphics will increase curb appeal. I'll add that I've never done this and have never seen anyone else do it.

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.