repair to monolithic slab 1

[KAYAKER]

a local contractor poured a monolithic slab radient heat slab over compacted sand(30 x 36)for a private garage. the problem is that the slab is 14" out of square,the building official issued a stop work order untill this is corrected .
the contractor obtained the services of a PE who dictated saw cutting across the slab than drilling holes embedding # 4 bar 10" ( 20db) deep at 1 foot on centers than reforming this new section to be poured -doing so would provide a even exposure along this line in question.
the contractor only drilled in 2 " so as not to damage the pex radient tubing.
another stop work order was issued
the PE has since stated that 2 " of imbeddment is sufficient.
anyone have any thoughts --- is 2 " sufficient?

 

[mjohan]

If a Hilti adhesive, or equivalent, was specified as the epoxy bonding agent then they have tested values. 2" may not have a published value but the shear and any tension stresses that will occur are likely very small.

10" seems very deep to start with, which makes me think that an epoxy may not have been specified. Is that the case?

 

[Lutfi]

First, I would nothing but an adhesive type material to bong the bars in the exiting (already placed slab).

Second, without consulting any literature, my initial gut feel that 2 inch embedment does not sound enough (only my gut feel).

Third, I also think that 10 inch embedment is excessive. I think 4 to 6 inches would be sufficient.

Fourth, I would ask the engineer to substantiate the 2 inch embedment.

 

[mjohan]

Hilti HIT HY 150 Injection Adhesive Anchor:

1/2" rebar
Min. embed (published values) = 2"

 

[Taro]

Is this a structural slab? If it is just a nonstructural soil-supported slab-on-grade, then the reinforcing is just for crack control. The building official may be overstepping their bounds by issuing stop work orders.

 

[Lutfi]

While slab is supported by compacted soil, at least one would assume that is the case; ACI requires minimum reinforcement for shrinkage. The way to get around that is to construct the slab in concrete panels with dimensions that will minimize cracking. With panelized construction one must provide a good detail for the construction and control joints.

Regards

 

[KAYAKER]

the bar was not apoxied, thanks forthe information on hilti , i will contact the engineer to substantiate the 2 " embedment