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RE: Two way slab designed as one way

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You obviously do not understand how concrete slabs work. For redistribution
to occur, cracking must occur. Until this happens, the slab acts
elastically and the moments will follow the 2 way elastic load path. This
happens until cracks occur and then the moments will redistribute to follow
the load paths provided by your reinforcement. 
This cracking will be extremely bad unless reinforcement is provided to
control it thus meaning you will be providing extra reinforcement above
that normally required for strength. 
Designing as 2way does not "save" reinforcement as the full load must be
carried in both directions anyway.
A slab should be designed to act in the way that it wants to act unless
there is a very good reason to redistribute the moments and then crack
control must be considered. 

At 12:26 10/10/98 +0800, you wrote:
>Dick,
>
>How can there be flexural cracking  if   it  is designed to have one way
>action.
>In my opinion, the moments will be redistributed in the short direction
>before any failure occurs.
>
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>
>
>-----Original Message-----
>From:	Horning, Dick/CVO [mailto:dhorning(--nospam--at)CH2M.com]
>Sent:	Saturday, October 10, 1998 7:52 AM
>To:	'seaint(--nospam--at)seaint.org'
>Subject:	RE: Two way slab designed as one way
>
>You also need more than shrinkage/temp steel in the 16' direction, or there
>will be flexural cracking
>
>	-----Original Message-----
>	From:	Alex C. Nacionales [SMTP:anacio(--nospam--at)skyinet.net]
>	Sent:	Friday, October 09, 1998 4:31 PM
>	To:	seaint(--nospam--at)seaint.org
>	Subject:	Two way slab designed as one way
>
>
>	I would like your opinion on designing two way slabs as one way.
>
>	Ex.   12 ft x   16 ft  slab designed as one way  on the 12'
>direction.
>
>	My opinion is that it  is possible but it would be more economical
>to design
>	it as two way slab.
>
>
>	Alex C. Nacionales
>	A.C. Nacionales Construction
>
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> 
Regards  Gil Brock
Prestressed Concrete Design Consultants Pty. Ltd.
5 Cameron Street Beenleigh Qld 4207 Australia
Ph +61 7 3807 8022		Fax +61 7 3807 8422
email:	gil(--nospam--at)rapt.pcdc.com.au