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RE: Cylinder Breaks vs. Mix Design

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I too have had to return many first submittals for concrete mix designs. A
few weeks ago I received a mix submittal which included a coarse aggregate
sieve analysis stamped by a PE and stating that it complied with the
specifications. The aggregate was listed as #57 aggregate (as specified) but
the report showed the gradation limits based on #467 per ASTM C33. The
aggregate did not meet all of the limits for a #57 aggregate. Thus you can't
even trust a PE sealed test report which states that it meets the specs. The
spec also required submittal of deleterious substance contents in
aggregates, but that was not submitted; also, compressive test data was not
submitted and several other items either were not included in the submittal
or did not meet the spec. On the first page, the Contractor had signed a
required statement that the submittal had been checked against contract
requirements. It would appear that the Engineer cannot trust the submitted
information without checking it in detail against the requirements ... or
"Let the buyer beware".

> -----Original Message-----
> From: Tom.Hunt(--nospam--at)d-fd.com [mailto:Tom.Hunt(--nospam--at)d-fd.com]
> Sent: Wednesday, March 27, 2002 8:53 AM
> To: seaint(--nospam--at)seaint.org
> Subject: RE: Cylinder Breaks vs. Mix Design
>
>
> Randal,
>
> I will add to Robert's comments that I don't believe I have
> ever received a
> correct concrete mix submittal on the first try.  ACI 301 Section 4
> provides all the details of what the supplier should submit
> and I would
> insist on getting it.  Once you get the proper information
> then I would
> scour it with a fine tooth comb.  I just received several mix
> designs this
> year with aggregate gradations out of spec among other
> things.  Get a copy
> of ASTM C33 and verify the course and fine aggregate
> gradations.  Verify
> the correct cement type which is probably called out in your
> soils report
> as either Type I, II, or V.  Calc out the water/cementitious ratio and
> check the proposed air content to insure it matches your exposure
> conditions.  Slump is very important and in general (assuming nothing
> special) should be 4 inches.  I just had a submittal with a
> proposed slump
> of 1 to 2 inches (yikes!! how do you even get it out of the
> truck without
> adding water!?!).  If additives are being proposed check the
> vendor data
> sheet for typical dosage rates.  It is easy to read 6 oz.
> instead of 0.6
> oz.  This may seem silly but check the proposed strength on
> the mix design
> sheet.  I just had a 4000 psi submittal when we requested
> 5000 psi.  Check
> where the water is coming from.  If the water is coming out
> of a river or a
> well then I would have it tested.  I once had some bad concrete due to
> contaminated river water and well water can become very
> brackish (i.e. full
> of salts).
>
> Good Luck,
>
> Thomas Hunt, S.E.
> Duke/Fluor Daniel


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