Tensile Testing

This test is a measure of the tensile strength of a biscuit shaped sample of rock core. In this the width of the specimen is approximately ¼ the core diameter. It involves gluing two pairs of plates to each side of the core section. The core is then loaded to break the rock in tension while monitoring the deformation across the gap between the plates prior to failure. This enables a tensile modulus to also be measured and any uneven loading to be detected. The test is particularly relevant to tensile failure perpendicular to bedding or foliation and has particular applicability in determining goaf formation characteristics.

This test is used to measure the tensile strength of core to axial loading. It follows ASTM D2936-20. It involves gluing tubes to each end of a piece of core and then axially loading it to failure. The results are reported in terms of tensile stress. In homogeneous rock the result of the test is a simple tensile strength. If conducted on core which is laminated perpendicularly to the core it provides the tensile strength across the laminations. This may be particularly relevant to roof falls or caving behaviour in laminated rock.