On Thu, 10 Jun 2021 16:28:38 -0700 (PDT), "
wrote:

On Wednesday, June 9, 2021 at 7:54:32 PM UTC-5, John B. wrote:

Modern concrete
Typically, a batch of concrete can be made by using 1 part Portland
cement, 2 parts dry sand, 3 parts dry stone, 1/2 part water.

John B.

Not to get off topic. !!!!!!!!!!!!!!!!! What is the topic anymore?
I've only dealt with concrete once in my life I think. Last summer I helped put a deck on and we anchored the posts in concrete. We used the ready to use bags you buy at the hardware store. Dump the bag into a wheel barrow and add some water and mix it with a shovel. Then pour in the hole. No measuring involved. Water is just whatever looks right so it mixes up to be however dense or soupy seems right.

What is a "part"? Your recipe above says parts frequently. Cement comes in bags. 50 pounds maybe. Dry powder basically. Sand and stone are measured be weight? or volume? 50 pounds of sand? 150 pounds of stone? or 2 buckets or bags of sand? 3 buckets or bags of stone? 1/2 bucket of water? 1/2 barrel of water? 1/2 bag of water?

"Parts" means "part" usually accepted as a specific amount in the
formula given. Example, 1 gallon of water mixed with one gallon of oil
is one part water and one part oil. One ounce of whiskey with one
ounce of water is one part whiskey and one part water.

I'm not sure about machine mixed concrete but certainly hand mixed is
measured by the shovel full for the cement, sand and aggregate and the
water is measured by eye depending on how liquid one wants the
concrete to be.

The usual proportions are in the neighborhood of 4 - 2 - 1, 4 parts of
the crushed rock aggregate, 2 parts of sand and 1 part of cement.
Within limits the less water used the stronger the concrete will be.
--
Cheers,

John B.