What is the typical size of concrete test cylinders?

The typical size of concrete test cylinders used in standard testing is 6 inches in diameter and 12 inches in height. This size is chosen because it provides a good representation of the concrete's strength and consistency, allowing for reliable and standardized results when performing compressive strength tests. The dimensions are established by standards such as ASTM C31 and ASTM C39, which are commonly referenced in the testing of concrete samples.

The 6 by 12 inch cylinders are preferred for their ease of handling and the ability to produce sufficient material volume for multiple tests, should it be necessary. The size also ensures that there is adequate space for the concrete to develop its properties without interference from external factors. In contrast, the other sizes listed, such as 4 by 8 inches, while also in use in some contexts, are not the industry standard for most compressive strength evaluations.