concrete question

Posted by Mark on October 30, 2006, 9:34 am

Good morning.

What happens to concrete as the ratio of aggregate to sand is reduced? I am
asking about this because I am attempting to duplicate some factory-made
patio blocks, and they appear to use a relatively small amount of some
finely-screened pea gravel. I think they do this so that their split faces
to not show a lot of rock.

Thanks
-Mark

Posted by DanG on November 1, 2006, 1:35 am

Most CMU products are made with Hadite or some other lightweight
aggregate to keep the unit weight down. If weight is not a factor
you might be able to go to the local concrete ready-mix company
and buy concrete sand which will have sand and rock up to 1/4".
This might make the look you are after. Be aware, if you are
trying to match color, that concrete is very subject to the color
and source of the sand.

___________________________
Keep the whole world singing. . . .
DanG

> Good morning.
> What happens to concrete as the ratio of aggregate to sand is
> reduced? I am asking about this because I am attempting to
> duplicate some factory-made patio blocks, and they appear to use
> a relatively small amount of some finely-screened pea gravel. I
> think they do this so that their split faces to not show a lot
> of rock.
> Thanks
> -Mark
>

Posted by RicodJour on November 1, 2006, 8:45 am

DanG wrote:

> Most CMU products are made with Hadite or some other lightweight
> aggregate to keep the unit weight down. If weight is not a factor
> you might be able to go to the local concrete ready-mix company
> and buy concrete sand which will have sand and rock up to 1/4".
> This might make the look you are after. Be aware, if you are
> trying to match color, that concrete is very subject to the color
> and source of the sand.

And, like mortar, to the amount of water in the mix.

R

Posted by Mark on November 1, 2006, 11:08 am

> Most CMU products are made with Hadite or some other lightweight aggregate
> to keep the unit weight down.

Hmm. . .yes, this does look like what they are using:

http://www.canleyworks.com/temp/haydite.jpg

It's even the right color.

Off I go to look for some. . .

-Mark

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