I'm looking for a concrete recipe that specifies the components (cement,
sand, stone) in terms of weight - not volume. It's easier to pre-weigh
the components instead of eye-balling them in a graduated bucket. Cement
powder is especially hard (and messy) to measure by volume.

I'm mixing this in a 3 cf mixer, my past experience is that the largest
batch I can mix is about 170 lbs worth of material.

I'm also wondering how strength is a function of the cement to stone
ratio (again, in ratio terms of weight - not volume).

I've been trying to work backwards from the usual formula (1:2:3) by
figuring out the density of the components. Based on my own
measurements:

Dry "brick" sand: 106 lbs per cubic foot
Crushed 1/2 stone (granite?): 97 lbs per cubic foot
Crushed 3/4 stone (granite?): 103 lbs per cubic foot

I took my 3/4 stone bucket and filled it with water to see how much
void-volume it had. The void volume was 37%. If I correct for voids, my
stone has a density of 163 lbs per cubic foot (practically identical to
the numbers I found for solid granite).

I haven't measured a sample of cement to get it's density. That's the
real important variable I think. No real hard data on that on the net
as far as I can find.

On Tue, 22 Jun 2010 21:26:32 -0400, Joe Guy wrote:

I'm looking for a concrete recipe that specifies the components (cement,
sand, stone) in terms of weight - not volume. It's easier to pre-weigh
the components instead of eye-balling them in a graduated bucket. Cement
powder is especially hard (and messy) to measure by volume.

Graduated bucket? Not for me-- I use a 2 gal bucket for my cement,
a 4 gallon for the sand & 2-3's for the gravel. [actually 5's with
paint marking the 3 gallon mark]

I can't imagine weighing everything for every batch.

Jim

On Jun 22, 8:26*pm, Joe Guy wrote:
I'm looking for a concrete recipe that specifies the components (cement,
sand, stone) in terms of weight - not volume. It's easier to pre-weigh
the components instead of eye-balling them in a graduated bucket. Cement
powder is especially hard (and messy) to measure by volume.

I'm mixing this in a 3 cf mixer, my past experience is that the largest
batch I can mix is about 170 lbs worth of material.

I'm also wondering how strength is a function of the cement to stone
ratio (again, in ratio terms of weight - not volume).

I've been trying to work backwards from the usual formula (1:2:3) by
figuring out the density of the components. Based on my own
measurements:

Dry "brick" sand: 106 lbs per cubic foot
Crushed 1/2 stone (granite?): 97 lbs per cubic foot
Crushed 3/4 stone (granite?): 103 lbs per cubic foot

I took my 3/4 stone bucket and filled it with water to see how much
void-volume it had. The void volume was 37%. If I correct for voids, my
stone has a density of 163 lbs per cubic foot (practically identical to
the numbers I found for solid granite).

I haven't measured a sample of cement to get it's density. *That's the
real important variable I think. *No real hard data on that on the net
as far as I can find.

Dont forget, weigh the water

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.

"Joe Guy" wrote in message ...
I'm looking for a concrete recipe that specifies the components (cement,
sand, stone) in terms of weight - not volume. It's easier to pre-weigh
the components instead of eye-balling them in a graduated bucket. Cement
powder is especially hard (and messy) to measure by volume.

I'm mixing this in a 3 cf mixer, my past experience is that the largest
batch I can mix is about 170 lbs worth of material.

I'm also wondering how strength is a function of the cement to stone
ratio (again, in ratio terms of weight - not volume).

I've been trying to work backwards from the usual formula (1:2:3) by
figuring out the density of the components. Based on my own
measurements:

Dry "brick" sand: 106 lbs per cubic foot
Crushed 1/2 stone (granite?): 97 lbs per cubic foot
Crushed 3/4 stone (granite?): 103 lbs per cubic foot

I took my 3/4 stone bucket and filled it with water to see how much
void-volume it had. The void volume was 37%. If I correct for voids, my
stone has a density of 163 lbs per cubic foot (practically identical to
the numbers I found for solid granite).

I haven't measured a sample of cement to get it's density. That's the
real important variable I think. No real hard data on that on the net
as far as I can find.

Buy a copy of Pocket Ref by Thomas Glover at Ace, or similar store. A
wonderful pocket book for DIYers. Tons of useful information, and it will
answer your questions.

Steve

visit my blog at http://cabgbypasssurgery.com watch for the book

A fool shows his annoyance at once, but a prudent man overlooks an insult.

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

"Joe Guy" wrote in message ...
I'm looking for a concrete recipe that specifies the components (cement,
sand, stone) in terms of weight - not volume. It's easier to pre-weigh
the components instead of eye-balling them in a graduated bucket. Cement
powder is especially hard (and messy) to measure by volume.

I'm mixing this in a 3 cf mixer, my past experience is that the largest
batch I can mix is about 170 lbs worth of material.

I'm also wondering how strength is a function of the cement to stone
ratio (again, in ratio terms of weight - not volume).

I've been trying to work backwards from the usual formula (1:2:3) by
figuring out the density of the components. Based on my own
measurements:

Dry "brick" sand: 106 lbs per cubic foot
Crushed 1/2 stone (granite?): 97 lbs per cubic foot
Crushed 3/4 stone (granite?): 103 lbs per cubic foot

I took my 3/4 stone bucket and filled it with water to see how much
void-volume it had. The void volume was 37%. If I correct for voids, my
stone has a density of 163 lbs per cubic foot (practically identical to
the numbers I found for solid granite).

I haven't measured a sample of cement to get it's density. That's the
real important variable I think. No real hard data on that on the net
as far as I can find.


From "Concrete and Masonry" By Richard Day sixth edition, MCMLXIX

High quality concrete should follow the formula:
26% fine aggregate (sand)
6% entrained air
16% water
42% coarse aggregate

In pounds for one cubic foot that works out to:
21 lbs of cement
10, 9, or 7.5 pounds of water depending on sand being (damp, wet, very
wet)
46, 47, or 49 pounds of sand depending on sand being (damp, wet, very
wet)
63 pounds of stone
2 tsp of air entrainment agent.

Never bothered with the air entrainment agent myself. The recipe makes a
good mix. You can adjust as needed to match the size batch to your recipe.


--
Colbyt
Please come visit http://www.househomerepair.com

On Jun 22, 9:29*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.

I was kidding about the water, I dont weigh a mix and dont know why
you are wasting time doing so, Volume is the way its done.

On Jun 23, 7:25*am, ransley wrote:
On Jun 22, 9:29*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.

I was kidding about the water, I dont weigh a mix and dont know why
you are wasting time doing so, Volume is the way its done.

Sounds like he is doing pre measured batches so he can just add water
when needed. Do this bt volume in some 5 gal buckets would work as
well.

Jimmie

ransley wrote:

I was kidding about the water, I dont weigh a mix and dont know why
you are wasting time doing so, Volume is the way its done.

I don't understand why you people have a hangup about weighing the
components.

It's very easy to fill these pails with sand and stone, and get weight
bang-on right off the bat. A household digital weigh scale shows the
weight to the closest 1 lb, and most times you just have to add or
remove a scoop of sand or stone to get the desired weight.

I have 20 pails of stone, 20 pails of sand, 10 pails of cement, all
pre-weighed and lined up and ready to go before I start mixing.

And what's more, I run the sand through a filter screen before putting
them in pails - to remove any organic crud, leaves, and other unknown
stuff that I don't want in my concrete. I also wash the stone using the
mixer (with 10 mm wire screen covering the opening of the mixer). I get
about one to two pails (about .5 to 1 cf) of silty-clay mud after
washing a ton of 1/2 crushed stone. I don't need that mud in my
concrete.

"Joe Guy" wrote in message ...
ransley wrote:

I was kidding about the water, I dont weigh a mix and dont know why
you are wasting time doing so, Volume is the way its done.

I don't understand why you people have a hangup about weighing the
components.

It's very easy to fill these pails with sand and stone, and get weight
bang-on right off the bat. A household digital weigh scale shows the
weight to the closest 1 lb, and most times you just have to add or
remove a scoop of sand or stone to get the desired weight.

I have 20 pails of stone, 20 pails of sand, 10 pails of cement, all
pre-weighed and lined up and ready to go before I start mixing.

And what's more, I run the sand through a filter screen before putting
them in pails - to remove any organic crud, leaves, and other unknown
stuff that I don't want in my concrete. I also wash the stone using the
mixer (with 10 mm wire screen covering the opening of the mixer). I get
about one to two pails (about .5 to 1 cf) of silty-clay mud after
washing a ton of 1/2 crushed stone. I don't need that mud in my
concrete.

Unless you totally screw up the proportions of components, most concrete
that you custom mix will do the job just fine. A lot of people have a
tendency to make it too watery, though, in my observances.

Steve

visit my blog at http://cabgbypasssurgery.com

A fool shows his annoyance at once, but a prudent man overlooks an insult.

On Wed, 23 Jun 2010 09:10:55 -0400, Joe Guy wrote:

I don't understand why you people have a hangup about weighing the
components.

Who are "you people"?! Who has "a hangup"?!

Just askin'

replying to Joe Guy, Kevin Kirkpatrick wrote:
I use a shovel and get close enough for a good mix.

--
posted from
http://www.homeownershub.com/mainten...me-449048-.htm