Once a cylindrical sample is extracted from the surface, the cores are first inspected to look for the degree of compaction, distribution of aggregates, crack defects, and honeycombing among others. Then, it will be sent to a lab to undergo a concrete compression test in moist conditions.
Other than determining the concrete compressive strength and density, the samples can also be used to see the depth of concrete carbonation, chemical analysis, water or gas permeability, and many more depending on where the structure is built and what the cement is employed to resist.