As indicated in the quoted clause, the testing will be done in accordance with CSA A23.2-9C (Compressive Strength of Cylindrical Concrete Specimens). That standard describes the details on how the compression tests will be performed.
To save you a bit of trouble, clause 7.4 of said document (specifically CSA A23.2-9C) states something along the lines of “The load should be increased until the specimen fails (i.e. shows visible cracks).”