The appropriate products specification is ASTM C90. The testing proceedure is ASTM C140.
You can essentially get the main portions of the specification/procedures free by going to ncma.org (National Concrete Masonry Association) site. Go to the TEK notes portion and select a state (any state) and a producer (any producer). Then, you can search by topic or use the index.
ASTM C140 requires SIX samples, THREE for weight, density, dimensions, area, % solids, absorption, etc. and THREE for compressive strengths. Units for compression testing CANNOT have been used for the weight, density, dimesnsions, etc.
The compressive samples should have a sampling date and testing as soon as possible to eliminate false curing that may change the compressive strength because there is no required time for curing as there is forconcrete lab testing.
The specification applies to the properties "when delivered" to the site. Because of this you will have to determine a method to control the timing between "casting" and use.
In factory production, units usually meet the C90 requirements when they come out of the plant, but a construction site produced CMU will not have the same aggregate controls, batching, material handling and curing.
Despite the low standards set by ASTM C90, it will be a real challege for site produced units to meet the C90 specs unless the materials are very good and there is some relaxation on the dimension requirements.
Is this inspection in association with "Global"?