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RE: Permissible Sulfate Content in Concrete

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You could also specify a C 1157 HS cement.

C 1157 is the new performance spec for cement.

Regards,
Harold O. Sprague

> -----Original Message-----
> From:	Tom.Hunt(--nospam--at)d-fd.com [SMTP:Tom.Hunt(--nospam--at)d-fd.com]
> Sent:	Thursday, January 10, 2002 11:13 AM
> To:	seaint(--nospam--at)seaint.org
> Subject:	RE: Permissible Sulfate Content in Concrete
>
> John,
>
> Type II and Type V cements are used for moderate and severe sulfate
> exposure respectively, however, the key parameter for sulfate resistance
> is
> the water/cementitious (w/c) ratio.  PCA produced a report in 1989,
> "Durability of Concrete in Sulfate-Rick Soils", where they tested concrete
> samples with varying w/c ratios, cement content, cement type, mineral
> additives, etc.  As it turns out, with w/c ratios of 0.40 or less the
> cement type has little effect.  For good sulfate resistant concrete you
> would be better off with a low w/c and perhaps adding silica fume.  This
> can be an important point when performing overseas work where Type II or
> Type V cement may not be available or might be very expensive.
>
> Thomas Hunt, S.E.
> Duke/Fluor Daniel
>
> ----- Forwarded by Tom Hunt/DFD on 01/10/02 08:38 AM -----
>
>
>                     "Sprague,
>
>                     Harold O."           To:     "'seaint(--nospam--at)seaint.org'"
> <seaint(--nospam--at)seaint.org>
>                     <SpragueHO@bv.       cc:
>
>                     com>                 Subject:     RE: Permissible
> Sulfate Content in Concrete
>
>
>                     01/09/02 09:49
>
>                     AM
>
>                     Please respond
>
>                     to seaint
>
>
>
>
>
>
>
>
>
> You really need to get some definition on the sulfate concentration.
> Sulfate concentrations in soil samples are as follows:
> Negligible           0.00 to 0.10
> Moderate        0.10 to 0.20
> Severe          0.20 to 2.00
> Very Severe          2.00 or greater
>
> What is evaluated is the water soluble sulfate in soil as a percent of the
> sample weight.  If the guy providing the testing has any experience, he
> should have given you the correct data.
>
> You need to look at Sec. 4.3 on sulfate exposure and remedies.
>
> The correlation you ask for does not exist.  The concrete degradation is
> time and temperature dependent.  Given enough time, your piles will go
> away
> entirely.  If it is hot, they go away faster.  ...How's that for vague?
>
> You can find commentary and references in ACI 318 Sec. 4.3.  You might
> also
> want to pick up a copy of the Concrete Manual by the Bureau of
> Reclamation.
> They have a good section on sulfate attack.  They should, they are based
> in
> Denver where they have many hot sulfate areas.
>
> If you need any more definitive information, let me know.
>
> Regards,
> Harold O. Sprague
>
> > -----Original Message-----
> > From:         John Joman [SMTP:jojoman34(--nospam--at)yahoo.com]
> > Sent:         Wednesday, January 09, 2002 11:34 AM
> > To:           seaint(--nospam--at)seaint.org
> > Subject:           Permissible Sulfate Content in Concrete
> >
> > Here is a question for all you concrete experts out
> > there.  I have received some preliminary test results
> > from concrete specimens taken from the piles of an
> > existing building.  Results indicate that sulfate
> > contents range from 0.5% up to 2.5%.  (Not sure if
> > this is by total weight of specimen or by total weight
> > of cement).  It was also reported that chunks of
> > concrete could also be removed by hand at some
> > locations.
> >
> > I understand that sulfates reacts with the calcium in
> > the concrete to slowly degrade the cement matrix.   My
> > question is, what percentages constitutes a  mild,
> > moderate, and severe exposure?  Chapter 4 of ACI does
> > provide maximum permissible chloride contents in
> > concrete, is there a similar table for sulfates?  Is
> > there any correlation between sulfate content and
> > reduced concrete strength (i.e. 5% sulfates equals a
> > loss of 10% in concrete compressive strength).
> >
> > If anyone can provide some useful references or
> > insight into this matter, it would greatly be
> > appreaciated.
> >
> > Thanks.
> >
> > John
> >
>
>
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