Apparatus for disc biaxial flexure and ring burst testing of large ceramic specimens

The construction of test equipment to measure the tensile strength of large, geometrically simple, ceramic specimens with coarse microstructures is described. The equipment utilises hydrostatic lending and the hydraulic medium is pressurised using a universal testing machine operating in compression. The equipment was constructed in a modular form with interchangeable specimen support assemblies which means that it can be used for testing either brick wall rings (pipe sections) of large discs. It has been used in both modes to evaluate the strength of coarse thick clay materials. Fracture strengths obtained using these tests show appreciable differences from those obtained using a 3-point bend test, reflecting the greater volumes of material tested in the apparatus described here. (C) 1995 The Institute of Materials.