wet setting rebar

[RCCpm]

This thread, thread507-244716 has some very strong language against wet-setting rebar. Can anyone explain why this is such a bad idea? This thread talks mainly about rebar in retaining walls and foundations. What about dowels from the foundation wall into an 8" CMU wall? Is it ok to wet set these dowels?

 

[BAretired]

The bond between the bar and the concrete is likely to be poor, so if you are relying on bar development, it is not a good idea.

BA

 

[Ron]

Further, depending on when the wet setting is done, you can displace the coarse aggregate and create a void in the concrete that makes the condition BAretired noted even worse.

There's no good reason to do it and many reasons not to.

 

[a2mfk]

I forgot some things-- typically you will have a hooked bar at the end of your vertical rebar that is embedded into the footing, which really could get messy if you wet set. They usually just tie the hooks to the continuous footing rebar. I am not sure if I have ever seen this wet set, I sure would not want it on my job. I would think for inspection purposes not many building departments would allow this either.

Maybe most importantly, and someone I think mentioned this, is you lose control over the exact positioning of the vertical rebar in the CMU wall. By design you need these at very specific spacings and in the center of your wall (or whatever your design calls for).

I'm piling on here with the others, don't do it, you could have a big headache down the road with RFI's, field fixes, etc, etc. I actually had a nightmare of a job with misplaced rebar that I had almost shut out of my memory!

Is the GC pressuring you on this? I would be really careful with them if that is the case, this is sloppy practice at best...

 

[TXStructural]

Everyone else has covered the physical reasons well enough, so: The codes prohibit it.

ACI 318 7.5.1 - Reinforcement including tendons, and post-tensioning ducts shall be accurately placed and adequately supported before concrete is placed, and shall be secured against displacement within tolerances permitted in 7.5.2.
And,
IBC 2006 1907.5 (in part) Reinforcement shall be accurately placed and adequately supported before concrete is placed.

ACI 530/TMS 402 does not cover this application (since it is the CIP concrete part of the job.)

 

[rscassar]

I thought the thread which you have referenced has some good issued made by the posters of this forum. Since reading that thread when it come around, I have always ensured that all reinforcement is in place and securely fixed prior to placing concrete. This is to ensure that good compaction and bond occurs all around the reinforcement. This is critical for reinforcement where it is required to transfer significant tension force such as at the base of a cantilevered retaining walls. I look for this onsite for all embedded items (hold down bolts included).

I am not so concern about wet sticking dowels if they are only required to transfer shear force.