Friday, September 9, 2011

RE: Old Structural Mesh BF912

My first edition CRSI came out in 1952.  The project in question was constructed in the 1930's.  So the CRSI handbooks will not have the conventions used in the 1930's. 

Regards, Harold Sprague
 
> From: mli@tb-engr.com
> To: seaint@seaint.org
> Subject: RE: Old Structural Mesh BF912
> Date: Fri, 9 Sep 2011 15:12:46 -0500
>
> Daryl, Neil & David:
>
> Thanks for all your replies and valuable information. I don't think we have
> budget for sample testing. I found 1963 CRSI handbook in our office
> library. Under Concrete Joist Construction, for 3" top slab, 4 x 12 - 8/12
> Welded Wire Fabric listed, which makes sense changing from 9 gauge (0.1483"
> Dia.) in 1930's to 8 gauge (0.1620" Dia.) in 1960's. The existing drawings
> are in very good condition. The reinforcing BF912 Mesh can be read without
> any difficulty in typical detail and general notes. My best guess for BF is
> British Fabric! Anyway, the existing 3" slab cannot support increased
> concentrate loads. We are going to field verify the locations of existing
> joists & install new raised floors for storage.
>
> Thanks again and have a great weekend,
>
> Martin
>
>
> -----Original Message-----
> From: David B. Merrick, SE [mailto:mrkgp.se@gmail.com]
> Sent: Thursday, September 08, 2011 9:41 PM
> To: seaint@seaint.org
> Subject: RE: Old Structural Mesh BF912
>
> I wonder if the written BF letters are actually BW for Birmingham Wire
> or British Wire
>
> I would preliminarily assume a square wire mesh of 12" with a 9 guage
> wire. My experience the strengths will be very close to standard loads
> if not then try 9 inch square with 12 gage.
>
> Watch out for less steel in gages rated by American Wire or Browne & Sharpe
>
> The Carnegie steel hand book of 1926 showed the following wire gage
> sizes, in inches, and all wire had a design strength of 20 ksi
>
> 9ga= 0.418 12ga= 0.109 Birmingham Wire BWG or Stubs Iron Works
> 9ga= 0.114423 12ga= 0.080808 American Wire or Browne & Sharpe
> 9ga= 0.1483 12ga= 0.1055 American Steel & Wire Co formerly
> Washburn & Moon
> 9ga= 0.145 12ga= 0.105 Trenton Iron Company
> 9ga= 0.144 12ga= 0.104 British Imperial Standard Wire SWG
> 9ga= 0.1398 12ga= 0.0991 Standard Birmingham Sheet and Hoop BG
>
> David Merrick, SE
>
> ----------------------------------------------------------------------------
> --
> From: nma [mailto:nma@nma-se.com]
> Sent: Thursday, September 08, 2011 4:26 PM
> To: seaint@seaint.org
> Subject: Re: Old Structural Mesh BF912
>
> >From Singleton - Copyright 1933, 1937,1947 - textbook at Cal Poly - 1950's:
>
> Page 5: Welded Wire Mesh possibly interpreted as longitudinal steel: 9
> gage at 4" spacing, transverse steel 12 gage at 12" spacing. Area/foot -
> long: .052 in2, transverse steel: .009 in2. Obviously this would be for a
> one-way type of slab. I can't find anything on what the "BF" is. It might
> be B(?)Fabric!
>
> My CRSI handbook is 1952 (first one) and they have a 4 x 12 - 9/12 listed
> for One-Way Types.
>
> Neil Moore, PE, SE
>
>
> On 9/8/2011 11:15 AM, David Topete wrote:
> That's a tough one to figure out. Any good leads yet? I'll check our
> office library, but it sounds like a proprietary call-out. My guess is the
> 9 means a No. 9 wire. Maybe spaced at 12"o.c. Good luck with this one.
> On Wed, Sep 7, 2011 at 2:25 PM, Martin Li <mli@tb-engr.com> wrote:
> All,
>
> We are working on a project that involves an existing reinforced concrete
> building with the drawings dated 1937. The reinforcing specified for 3"
> slab over joists is BF912 Mesh. Does anyone know BF912 Mesh?
>
> TIA
>
> Martin Li, P.E.
>
>
>
>
> --
> David Topete, SE
>
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