Concrete question

[bluedog225]

Back in 2019 I had the slab poured for my workshop/cabin. Since we were drilling piers anyway and had the big drill rig, I had them go ahead and drill and bell four 12” piers for the eventual deck on the front of the place.

Grade was about 3’ down for one pier due to a temporary drainage ditch from the slab area. I put some big sticks of rebar in each hole for future tie in.

I’m going to pour a 2’x2‘ plinth on top of the piers and embed a welding plate. Then steel above.

I’m trying to decide whether concrete bonding adhesive is a better choice or some black, tar-like stuff I bought that was designed for water sealing the joint between a concrete slab and concrete wall.

It’s going to be a cold joint either way. I think keeping water away from the rebar is my primary goal and am leaning towards the black goop. And I’ve never really had a lot of faith in concrete bonding adhesive.

What do you guys think?

Thanks

 

[egdede]

Bonding adhesive on a properly cleaned surface then coat the 'seam' and above with black goop.

 

[bluedog225]

That’s a good idea. Or I could put the black stuff around the outer two inches or so. I was thinking all or nothing.

Does bonding adhesive really do anything that matters in real life though? I can’t imagine it improves the bond enough to be structurally material.

 

[wssix99]

Does bonding adhesive really do anything that matters in real life though?

Not in this application. Concrete is porous and the rebar is going to see water no matter what. (Unless you were to foundation seal the entire thing, which is not necessary.

The rebar in the foundation of your house is probably damp. Its not a big deal. Air sealing the joint after the fact might help a little.