In testing concrete, what does the split tensile test primarily help to determine?

The split tensile test is primarily designed to measure the tensile strength of concrete. In this test, a cylindrical specimen of concrete is subjected to a compressive load along its length. As the load is applied, the specimen eventually fails in tension, which occurs due to the tensile stresses that develop across the diameter of the cylinder. This test is particularly relevant for concrete, which is inherently strong in compression but relatively weak in tension.

By determining the point at which the concrete fails under this loading condition, engineers can establish a reliable estimate of the material's tensile strength, which is crucial for assessing how well the concrete will perform in various structural applications where tensile forces are present. This understanding helps in designing structures that are not only durable but also resistant to tensile stresses that can lead to cracking and structural failure.