Which testing method is commonly used to check the compressive strength of concrete?

The cube test is a widely recognized method for assessing the compressive strength of concrete. This test involves casting concrete into cube molds, typically measuring 150 mm on each side, and then curing them under controlled conditions. After a specific curing period, usually 7 or 28 days, the cubes are subjected to a compressive load until they fail. The maximum load sustained by the cube is recorded, and the compressive strength is calculated by dividing this load by the cross-sectional area.

This method is preferred because it provides a reliable and direct measure of the concrete's ability to withstand axial loads, which is crucial for structural integrity. In most engineering standards, including those used in the construction industry, the compressive strength obtained from the cube test is used to ensure that the concrete meets the required specifications for various applications.

Other methods, such as the flexural test, primarily evaluate tensile strength, which is not the same focus as compressive strength. The slump test assesses workability, and the water absorption test indicates porosity, but they do not provide direct measurements of compressive strength. Hence, the cube test is the standard method for this purpose.