On Jun 22, 10:29*pm, Joe Guy wrote:
ransley wrote:
*Dont forget, weigh the water

I don't weigh the water, and here's why:

When I mix, I'll mix anywhere from 4 to 10 batches straight over a 1 to
3 hour period (4 batches for a pier, 10 batches for a verticle wall slab
10' long, 4' high).

I'll have 5 pre-weighed pails ready for each batch, and enough pails
ready to do all the batches I need (these are .5 cf rectangular
cat-litter pails).

One pail for the cement, 2 for stone and 2 for sand. *Remember, these
are not equal parts by volume. *I have 23 lbs cement, 88 lbs stone and
58 lbs sand. *For the piers, I'll go heavier on the cement and lighten
up on the sand.

For the first batch, the mixer will be clean, and I could prepare a
specially weighed batch of water for that batch. *But once I pour and
place that batch, I'll take a hose and spray down the lip and inside of
the mixer (specifically, the blades) to loosen up what-ever caked cement
has formed there). *

This places an unknown / variable quantity of water in the mixer prior
to adding the components of the next batch. *About a gallon or two I
would guess.

I then add the following, in this order:

100% of the stone
100% pigment

I let that mix for about 1 minute, let the pigment get distributed
equally all over / into the stone. *The stone / pigment will absorb most
or all of the standing water that was in the mixer already, and I will
probably give it a few extra shots of water, then I add

50% cement

Let that mix for a minute, then add

50% sand

Let that mix for a minute. *Spray some water into it to keep it from
caking up at the back of the mixer. *Then add

25% - 40% cement and 25% sand

Let that mix for a few minutes. *Spray more water.

At this point, I will throw in 1/2 shot-glass of Airex, and 2 shots of
Eukon-37 (super-P). *I found that adding the super-P later in the mixing
cycle when more of the ingredients were in play was more effective than
at the start of the mix cycle. *I've also found that the mix needs to be
a bit chunky for the super-P to do it's job really well.

The super-P turns the mix into a more runny consistency, perhaps a bit
sloppy. *At that point I might have a little more cement to add, and
about 25% of the sand. *This is enough to turn the mix from a bit sloppy
into that "rolled-dough" consistency that I aim for.

If I end up with a mix that's too sloppy, I'll add extra cement and
stone to thicken it up (I always have a stand-by bucket of stone and
cement ready in case I need it).

There are times when I have to take a 3-foot long rebar and dig into the
mixer while it's turning to loosen anything that's caking on the blades
or at the back of the mixer. *I'll do that instead of spraying water at
it. *My goal is to keep the mixing time down to an absolute minimum,
including no downtime to clean the mixer between batches. *This is why I
spray water into mixer when and as much as I think it needs.


You are making concrete, not performing brain surgery...

The only situation in which concrete ingredients would be measured
by weight would be at a concrete plant when the machines are being
used to produce a batch...

Seriously, by proportional volume is close enough for home repairs,
you aren't submitting samples afterward for material strength
testing...

~~ Evan