What kind of sample is used for a flexural test?

In a flexural test, the appropriate sample used is a concrete beam sample. This testing method evaluates the material's ability to resist deformation under load, which is critical for understanding the material's performance in applications where bending stresses are present.

Concrete beams are designed to have a specific geometry that allows for effective measurement of flexural strength. They can be subjected to loads applied at specific points or distributed across their length to determine how they respond to bending forces. The data gathered from a flexural test on a concrete beam helps engineers predict how concrete will behave in real-world scenarios, such as in beams used in construction.

In contrast, concrete cylinders are typically used for compressive strength tests, cubes are also used for compressive tests, and blocks do not provide the specific geometry needed to accurately assess flexural properties. Thus, the concrete beam sample is the best choice for performing a flexural test and is fundamental for assessing the structural integrity of concrete in flexural applications.