Friday, September 11, 2009

Re: Concrete Cure Time

Currently in southern CA slag is not available at an economically
feasible cost; FA is your only realistic option for recycled cementious
material replacement. High fly ash (greater than 40% replacement) is
not common either down here but it does seem to be picking up steam and
is more common in other parts of the world. I have done a little
research on the subject and do not recall any info regarding Em:f'c
differences in HFA vs 100% PC concrete. Doesn't mean there isn't one as
I am pretty much a novice in this area. If you are interested send me
an email and I will forward some of the documents and information I have
complied from the internet and other sources on high fly ash in general
as well as specific to southern CA.

Donny Harris, SE
California


Contractors will want you to get rid of the flyash completely and use
Slag.
The concrete apparently stays too wet for too long using high amounts
fly
ash.

-gm

On Thu, Sep 10, 2009 at 3:17 PM, <ASLCSE@aol.com> wrote:

> Great input, Harold. I have a related (I think) question regarding
> strength.
> A couple of days ago I went to a GREEN seminar. The speaker told us
that
> using a great amount of fly ash (replacing part of the PC) will
greatly
> reduce the CO2 into the air. I know that fly ash will also act as a
retar=
der
> (for the concrete strength). Question: Is the strength vs. the modulus
of
> elasticity curve the same as for using portland cement ?
> Thanks
> Antonio S. "Tony" Luisoni
> Consulting SE
> Granada Hills, CA


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