Those seem to be the routine controls to determine the mix design and verification that the mix as sampled after arrival is within the guidelines to match the design mix.
A testing laboratory can easily take the cylinder samples, set up site curing, transport them properly to the testing location, complete the curing to test for 2, 7, 14, 28 day and later testing specified. prepare the sample, break the cylinders and prepare reports.
Combining the sampling, site sample control, transportation and testing will put everything under one umbrella, as far as responsibility if the owner chooses this approach.
Adding extra materials (water, admix, etc. changes everything and places more responsibility on the site inspection and contractor. The cost of this responsibility must be recognized.
After that, it up the on-site materials inspector (whoever he works for), to verify that the concrete placement, finishing and site curing are done according to the specifications.
Dick
Engineer and international traveler interested in construction techniques, problems and proper design.