concrete sampling for compressive strength

huangyhg

concrete sampling for compressive strength
according to aci and astm new/ revised standards on concrete sampling/ or testing, concrete sampling can be tested by using 4鈥?* 8鈥?cylinders instead of 6鈥?* 12鈥?to find the compressive strength of the concrete. according to my understanding, instead of 6鈥?* 12鈥?with 2 cylinders for 28 days break, we have to sample 3 cylinders with 4鈥?* 8鈥?
if this is correct as per the new standard version, i appreciate if someone can let me know the standard number/ or spec.
thank you