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 microstruct ures is described. The equipment utilises hydrostatic lending and the hydraulic medium is pressurised using a universal testing machine oper ating in compression. The equipment was constructed in a modular form with interchangeable specimen support assemblies which means that it c an be used for testing either brick wall rings (pipe sections) of larg e discs. It has been used in both modes to evaluate the strength of co arse thick clay materials. Fracture strengths obtained using these tes ts show appreciable differences from those obtained using a 3-point be nd test, reflecting the greater volumes of material tested in the appa ratus described here. (C) 1995 The Institute of Materials.