Precast Column Base Connection to CIP Pilaster of Same Size
Precast Column Base Connection to CIP Pilaster of Same Size
(OP)
Normally, when I put a precast column on a CIP pilaster, I'll make the pilaster larger than the column by 3"-4" on all sides. That, to provide some tolerance and so that a standard four bolt precast base connection can be used without interference between the anchor bolts and the pilaster reinforcing. On a current project, I'm being asked to detail a precast base connection where the column and pilaster will have identical cross sectional dimensions. Is there a reasonable way to do that that is not cost prohibitive?
These are some options from a manufacturer's catalog for slightly different situations. One seems to show same sized precast columns successfully connected but I'm not sure if that would apply to a CIP pilaster. Also not sure how it was done.


These are some options from a manufacturer's catalog for slightly different situations. One seems to show same sized precast columns successfully connected but I'm not sure if that would apply to a CIP pilaster. Also not sure how it was done.


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.






RE: Precast Column Base Connection to CIP Pilaster of Same Size
I could think of a few ways to do it but no idea if it's feasible or cheap. Probably depends on the pilaster reinforcement and the loads involved. Can you provide a trademark KootK sketch of the pilaster and column reinforcement setup?
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RE: Precast Column Base Connection to CIP Pilaster of Same Size
RE: Precast Column Base Connection to CIP Pilaster of Same Size
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.
RE: Precast Column Base Connection to CIP Pilaster of Same Size
I would think close to how you have it. You'd just have to have that bolt gauge small enough to miss the ties/vertical reinforcing on the perimeter.
RE: Precast Column Base Connection to CIP Pilaster of Same Size
You might have to splay out the block out sides to allow better approach to the anchor nuts with a wrench.
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RE: Precast Column Base Connection to CIP Pilaster of Same Size
Hmmm... it hadn't really occurred to me that I could tinker with the bolt gauge. I thought 2" was kinda "it" based on 4" angles in the corner. I'll explore that with the precaster if they ever return my call(s). Based on the geometry that I'll mention in response to JAE, I think I could make this work with 5 x 5 recess angles instead of 4 x 4 giving me 3" to the anchor bolt centres. This only reduces the cross sectional contact area by 5%
Yes. I think that I can even improve upon that though. On two opposing sides (front/back), the pilaster will be larger than the PC column in order to create a ledge for incoming hollow core. This will move the anchor rods away from the tight corner area just as you have proposes. Bloody brilliant..
Now that I think of it, if desperate, I might even have other options here owing to the pilaster being longer, one direction, than the precast columns. I could plop some 3 x 3 clip angles on the sides of the column, outboard, and get it done that way.
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.
RE: Precast Column Base Connection to CIP Pilaster of Same Size
I don't remember the specific product that the PC manufacturer used, but I know Dayton Superior makes one (see page 113 here).
RE: Precast Column Base Connection to CIP Pilaster of Same Size
Dik
RE: Precast Column Base Connection to CIP Pilaster of Same Size
RE: Precast Column Base Connection to CIP Pilaster of Same Size
https://www.peikko.com/products/bolted-column-conn...
https://media.peikko.com/file/dl/i/yGix0w/0ZFj6oWs...
RE: Precast Column Base Connection to CIP Pilaster of Same Size
I do not think the Piekko base connections will work very well in this case where the sizes are equal.