Compressive Strength Tests -variations within a set

[concreteworld]

Hi,
Please advise what standards/codes we can refer to close a low compressive strength case where in a set of 6 cylinder samples taken from one composite sample, 1 result is fail and the other 5 are okay. The concrete grade is 45 Mpa.
Results are as below
56.1 Mpa
46.4 Mpa
40.3 Mpa
53.5 Mpa
55.9 Mpa
45.8 Mpa

Appreciate your responses...
Thanks in advance

 

[Ron]

Where are you located and what is the governing code for your construction?