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RE: Pumping Concrete and W/C Ratio

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We do tons of ACI 350 facilities all over the world.  Most are pumped.  The
w/c ratio has nothing to do with the pumpability directly.  

Pumps like, high range water reducers, fly ash, and fines.  Pumps,
especially boom pumps, will suck the air out of a mix.  Make sure you test
at the discharge, and adjust the air accordingly.  The amount of air sucked
out is more of a function of how much it drops.  A horizontal "slick line"
will not have as much of an effect as an boom "overhead" pump.

I have really become a fan of the polycarbonate high range water reducers,
because of their effectiveness when concrete is moved by any means.

Harold Sprague

> -----Original Message-----
> From:	Novak, Dan [SMTP:DNovak(--nospam--at)]
> Sent:	Wednesday, May 17, 2000 7:43 PM
> To:	seaint(--nospam--at)
> Subject:	Pumping Concrete and W/C Ratio
> What does a boom pump have to do with the water cement ratio.  We specify
> a
> 0.45 w/c for our water tanks per ACI 350, contractors have in the past
> pumped the mix.  I now have a contractor whining.  Is there an issue that
> I
> am not sensitive to.
> Thanks 
> Dan Novak