How to determine the volume of water per cubic meters of concrete?

By water cement ratio; it depends to the slump test requirement.

it is depend on the workability and stringth requirements

and the quantity of admixture in the concrete mix

with water/cement ratio for concrete 0.5 to0.65 is applicable.

W/C ratio in the respective code.

Different strength concrete have differing Water : Cement ratios and thus differing water volume

when you have W/C RATIO and if you have the quantity of cement then you can find the volume of water

For 1 Clubic meter of concrete are cement 300 kg 800 kg of sand and gravel 1000 has end added 180 liter of H2O.

to check the homogenity and keeps the commingling made the verification of the water content using a cone of Abram if the mixture is wet or the test of crushing if the cylindrical mold is dry.

and thank you.