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Epoxy Anchors at Cold Joint

Epoxy Anchors at Cold Joint

Epoxy Anchors at Cold Joint

(OP)
I have an existing spread footing I am adding on to and placing a pier above. Field observations have shown that, contrary to the original design drawings, the edge of the existing footing is inline with the epoxy anchor placement.

My question is, is it okay to proceed with epoxy install at this cold joint or would it be better practice to chip the existing foundation back a few inches and epoxy into the new footing expansion? The anchor rod location can not be moved due to project constraints. Attached a sketch

RE: Epoxy Anchors at Cold Joint

What forces are you expecting in the anchor bolts?
Is this a gravity column? Part of a moment resisting frame? Part of a braced frame?

RE: Epoxy Anchors at Cold Joint

(OP)
This is part of a braced frame

RE: Epoxy Anchors at Cold Joint

So what forces are you expecting in the anchor bolts?
Do you have a net uplift?
Horizontal shear parallel with the joint?
Horizontal shear perpendicular to the joint?
Gravity loads?

What are the rough magnitudes of the forces?

RE: Epoxy Anchors at Cold Joint

(OP)
There will be net uplift occurring at this column of around 10 kips, but not sure why the magnitude of the uplift would be important if the anchors are designed for the intended load. My questions is whether the epoxy bond to the surrounding concrete would be affected being it's located at a joint.

RE: Epoxy Anchors at Cold Joint

Apply all factors related to cracked concrete for post installed anchors, that essentially what you have at a cold joint. As long as the joint is clean and has a concrete surface to bond to, it should work.....in theory.

RE: Epoxy Anchors at Cold Joint

I would be more concerned with how you provide flexural continuity in the footing itself. Why are you not just replacing it?

RE: Epoxy Anchors at Cold Joint

I suspect that the edge of the existing footing would not be properly cleaned and you would not get a good bond.

As an alternative:
I suspect that you could develop 10k of tensile force in the two anchors that do not fall on the joint.
I suspect that you could develop 10k of capacity in just the top "cap" and another 10k of capacity between the cap and the "lower" footings.

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