Concrete Slab - Integrity Reinforcement Cut

[m1ke99]

On a two-way concrete slab (w/ drops at columns) contractor forgot to add some piping sleeves near a column and has decided it would be okay to core without scanning for rebar.
I looked in the hole and they cut 1 of the 3 bottom integrity bars.
Anyone have recommended repair details?

 

[Old Eng]

Notify your professional liability insurance carrier and be prepared for some significant expenses, assuming you OK'd the coring.

 

[WARose]

I've dealt with situations like this before. The first question is: what does this mean for the strength? You need to run some numbers to see what this does to the allowable floor load. It may not impact it at all.....and then again it could limit the repair efforts (including construction loads and sub framing weight).

The fix approaches are numerous.....you might try to chip back the concrete and try a splice. Or (as I alluded to before) possibly slip some sub framing (steel perhaps) underneath the floor that would re-direct the load to elsewhere in the floor framing.

 

[KootK]

I have a hard time imagining a reasonable fix that would restore the intent of integrity reinforcing. New beams column to column would do it but it’s hard to imagine that being acceptable. It’s doubly bad because you’ve probably lost the bar twice. Once on the side of the column where the core is at and once on the other side of the column where anchorage will be insufficient.

My first stop would be to recalculate the demand as tight as possible and compare that to the total number of bars going both directions. One bar in, say, six isn’t so bad. I’d probably let that go. Integrity reinforcing is hardly an exact science. Most reinforcement strategies would probably just weaken the connection anyhow.




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.