RE: slabs on grade...

David,

Contractors do not follow up on slab failures if they can help it and if forced to do so, they blame someone else and repeat the same mistake.  Engineers who do  investigate these slabs when they fail, find the mesh rusted out on the bottom (having been walked on during the pour) and of no value in controlling shrinkage cracking, curling or concentrated loading.  Rebar spaced wider than a Neanderthal's footprint (18") supported in chairs or dobies will do a better job.

Richard Hess SE

-----Original Message-----
From: David Fisher [mailto:dfisher@fpse.com]
Sent: Monday, October 29, 2007 8:45 AM
To: seaint@seaint.org
Subject: slabs on grade...

List:

Does anyone know where the minimum slab on grade reinf. is specified?

What we typically specify (6x6/W1.4xW1.4) doesn’t of course meet 0.0018 for a 4” or 5” slab,

But, like a contractor would say, “That’s how we’ve been doing it for years”

 

TIA,

 

 

David L. Fisher SE PE

Senior Director

 

Cape Cod Grand Cayman Holdings Ltd. - Cayman

Fisher+Partners Structural Engineers Ltd. - Cayman

372 West Ontario Chicago 60610

75 Fort Street Georgetown Grand Cayman BWI

319 A Street Boston 02210

 

 

312.573.1701

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