Concrete cores are used for testing of actual properties of concrete in existing structures such as strength, permeability, chemical analysis, carbonation etc. Sampling of concrete cores and testing its strength is described.
Concrete cores are usually cut by means of a rotary cutting tool with diamond bits. In this manner, a cylindrical specimen is obtained usually with its ends being uneven, parallel and square and sometimes with embedded pieces of reinforcement.
The cores are visually described and photographed, giving specific attention to compaction, distribution of aggregates, presence of steel etc.
The core should then be soaked in water, capped with molten sulphur to make its ends plane, parallel, at right angle and then tested in compression in a moist condition as per BS 1881: Part 4: 1970 or ASTM C 42-77.
The core samples can also be used for the following: