Indirect Tensile Test
Brazilian test is a geotechnical laboratory test for indirect measurement of tensile strength of rocks. Due to its simplicity and efficiently, it is amongst the most commonly used laboratory testing methods in geotechnical investigation in rocks. The test sometimes is used also for concrete.
The compression induces tensile stresses normal to the vertical diameter, which are essentially constant over a region around the center. The indirect tensile strength is typically calculated based on the assumption that failure occurs at the point of maximum tensile stress, i.e., at the center of the disc. He suggested formula for calculating the splitting tensile strength σt (MPa) based on the Brazilian test is (ASTM 2008; ISRM 1978):