Support of wwf in slab on grade
Support of wwf in slab on grade
(OP)
I have a project where the contractor wants to pour the concrete for the slab on grade then pull the wwf up through the wet concrete into position. Is this explicitly prohibited by the code (IBC or ACI)?
Thanks
Thanks






RE: Support of wwf in slab on grade
www.SlideRuleEra.net
RE: Support of wwf in slab on grade
It might be standard practice, but if you reference ACI as a designer, consider at the following
ACI 318, 7.5.1 "Reinforcement...shall be accurately placed and adequately supported BEFORE concrete is placed..." (emphasis mine)
I would argue that the 'pull it up through the wet concrete method' is disallowed by inference.
RE: Support of wwf in slab on grade
RE: Support of wwf in slab on grade
RE: Support of wwf in slab on grade
Almost every slab I've ever seen demolished, which had WWF in it, the wire was on the very bottom of the slab, or at least within 1/2" of the bottom.
And since slab reinforcing should be within the top 1/3 of the slab to do any good in controlling cracks...well, we've stopped specifying it for Slabs on grade...unless the contractor chairs it with bars at 4' o.c.
RE: Support of wwf in slab on grade
RE: Support of wwf in slab on grade
We have had some luck getting contractors to do it this way, however, other contractors are much more resistant to trying anything new. This method obviously requires more labor.
RE: Support of wwf in slab on grade
RE: Support of wwf in slab on grade
Specifying the placement of concrete bricks for support is a waste of time because 1) far too many are required to do it right, and 2) the WWF is walked down until you just have a bunch of "U" shaped WWF (over the bricks and down to the bottom and the over the bricks again). The best chairs for WWF are slab bolsters with sand feet placed 4' OC but the "U" effect occurs here too.
You guys would be a lot better off specifying #3 or #4 bars at 18” EW, bricks or slab bolsters with sand feet, and closer joint spacing that is sawed in as soon as practicable but not causing raveling of the stone.
Techmaximus
RE: Support of wwf in slab on grade
It seem, that in Concrete everything is a trade-off and it all depends on what you want to trade.
RE: Support of wwf in slab on grade