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RE: Conc Spec Question

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Roger/Harold -
  I missed the false set requirement under Table 4 of ASTM C 150(holding a
document 10 feet away no longer works when attempting to read small print).
ASTM C 451 defines false set as "the early development of stiffness in the
working charateristics of a portland-cement paste, mortar, or concrete
without the evolution of much heat, which stiffness can be dispelled and
plasticity regained by further mixing without addition of water; also known
as "grab set", "premature stiffening", "hesitation set," and "rubber set".

Thanks again guys.

Charlie

> ----------
> From: 	Roger Turk[SMTP:73527.1356(--nospam--at)compuserve.com]
> Reply To: 	seaint(--nospam--at)seaint.org
> Sent: 	Thursday, September 23, 1999 6:10 PM
> To: 	seaint(--nospam--at)seaint.org
> Subject: 	RE: Conc Spec Question
> 
> Charlie,
> 
> False set requirements are not restricted to Type II cement.  The false
> set 
> requirements are optional requirements set forth in Table 4 of ASTM
> C150-95 
> and all types of cement have the same minimum penetration requirements (50
> 
> percent).  Apparently the writer of the spec wanted to specify Type II 
> cement with this optional requirement.
> 
> The false set test is identified as C451.
> 
> Since ASTM is moving specifications away from where they logically belong,
> I 
> had to go back to my 1995 ASTM volume 04.02 to find the C150 requirements.
> 
> ASTM C150 is now published in volume 04.01, which I do not get.
> 
> Hope this helps.
> 
> A. Roger Turk, P.E.(Structural)
> Tucson, Arizona
> 
> Harold Sprague wrote:
> 
> >>Charlie,
> 
> The only thing that I have ever come across for a "false set" is:
> 1.      The super plasticized concrete that looses its slump and bleed
> water
> is often times viewed as a set, but it is not.
> 
> 2.      The hot and dry conditions that can crust over the top, but the
> concrete has not achieved a set.
> 
> I have not seen anything that is specifically in regard to Type II
> cements.
> 
> Let me know if you find out anything else.
> 
> Regards,
> Harold Sprague
> The Neenan Company
> 
> 
> -----Original Message-----
> From: Canitz, Charles F NAB02
> [mailto:Charles.F.Canitz(--nospam--at)nab02.usace.army.mil]
> Sent: Tuesday, September 21, 1999 9:19 AM
> To: 'Seaoc'
> Subject: Conc Spec Question
> 
> 
> While reviewing a concrete specification, I came across the following
> statement:
>    
> "Portland cement shall conform to ASTM C 150, Type II including false set
> requirements." Can someone define false set requirements and why it only
> applies to Type II cement?
> 
> Thanks,
> 
> Charlie Canitz<<
> 
>