slab on grade and saw cuts
slab on grade and saw cuts
(OP)
i am a concrete contractor and have been asked to form and pour a 6" slab on grade for a municipal project where there will be dumpsters (debris and green waste) sitting on the slab. about 1,500sqft. the slab is designed with a 4000psi mix.
the question is: the slab has been designed with a mat of #4 rebar AND saw cuts. i don't think i have ever seen a slab with a mat of rebar that is also saw cut. is this normal? thanks.
the question is: the slab has been designed with a mat of #4 rebar AND saw cuts. i don't think i have ever seen a slab with a mat of rebar that is also saw cut. is this normal? thanks.





RE: slab on grade and saw cuts
RE: slab on grade and saw cuts
RE: slab on grade and saw cuts
The saw cuts are an attempt to force the restraint shrinkage cracking to occur in a straight line rather than randomly.
Having said that, your question is a particularly good one for a slab being used as you describe. There will be a lot of debris on the slabs, and this dirt, grit, whatever, is bound to find its way into the joints unless the joints are well sealed and maintained, which in itself is unlikely.
When the joints are full of debris and the slab gets hot in the summer, enough force can build up to cause the slabs to slide, opening up the joints further, and on and on. If there are only slabs involved, that may not be an issue, but the slabs can move enough to damage perimeter elements. So while that should not be your problem if you do as you are told, it would be worth mentioning to your customer.
RE: slab on grade and saw cuts
RE: slab on grade and saw cuts
RE: slab on grade and saw cuts
Dik
RE: slab on grade and saw cuts
RE: slab on grade and saw cuts
RE: slab on grade and saw cuts
RE: slab on grade and saw cuts
Fill the joints with a semi-ridgid epoxy or polyurea based joint sealant.
If the steel is allowed to run through the joints it will add restraint and increase the potential for random cracking. The joints will then become nothing but maintenance issues.
Refer to the American Concrete Institutes document ACI 302.1R-04.Guide to Construction of Slabs.
RE: slab on grade and saw cuts