When concrete is poured, how much cubic do we take for testing?

Depend upon test but test on fresh concrete and casting of cylinders need one full wheel barrow

please refer to the table below from Australian Std. for a guide on concrete sampling frequency.

Thank you for the invitation

1- The sample shall be taken from the modern mixing concrete at the site and we shall fill (6) cube blocks with concrete(3) layers, and each layer is formed separately by the applicator rod (25-35) timesFor each layer so that the number of blows is distributed regularly on the surface of the concrete and after the completion of your blood layerThe top is leveled with the surface of the mold by the two controls, and the necessary data is written on the cubeConcrete and dated on its upper face the date of casting and concrete caliber (type).2 - Fill the molds filled with concrete away from the sun and any vibration for a period of (24) hours.3. The cubes shall be kept in situ at a distance from the vibrations and shall be covered for 24 hours and then removed from the moldsAnd samples and immersed in water and then samples samples three of them after (7days) and the other three after (28days)By testing the pressure loads immediately after removing them from the water and is still wet.4. Site tests shall be carried out during implementation to ensure that the properties of the concrete are consistent with those specifiedFor them, 6 molds must be tested for each origin or per day molding or per (100m ^ 3) of concrete in originThe resistance of the molds shall not be less than the specific resistance of the design.Concrete blocks are usually broken by 7days and 28 days.To determine the resistance of concrete at all ages, so that the cubes are placed between the surfaces of the pressure machine and apply a regular load, and then calculate the fractional effort (F) through the following equationF = P / AF = is the fracture voltage and unit (kg / cm2)P = Load and unit fraction (kg)A = is the area or surface of the concrete cube or cylinder flat and its unit (cm ^ 2).The required value of crushing fracture of concrete cubes taken at the site during castingAfter 3 days are 60-75%After 7 days it is 75-85% of the required fracture stress and the required value after 28 days is the resistance for which the concrete is designed, which is 100%.

Thanks for the invite. Sorry, the question is out of my field.

Thank you for the invitation

Agreed with colleagues

With greetings and appreciation

It is not my subject but thanks anyway for invitation. 

Number of cubes 6 taken every 100 m 3 concrete or when the batter or a construction element and cracking 3 after 7 days and 3 after 28 days

A concrete cube is of the size 150mm and thus it's volume will be 0.15 x 0.15 x 0.15 = 0.003375 Cubic meter

It depends on :

- the used standrds 

- The project specifications ( Client requirements ) 

if there is a difference between the standards and the client requirements , follow the client requirements but not less than the standards 

anyways :

according to the Egyptian standards , it will be 6 cubes/100m3 ... 3 cubes subjected to the comprission test after 7 days and the others after 28 days  ... and not less than 3 cubes for quantities less than 100 m3 ... 

The question needs to be revised for grammatical mistakes and furthermore, attempting to use literal translasion is not advised as iy makes sentences vunerable to criticism.