Experimental determination of the maximum indirect tensile stress parameters for dionysos marble

In this study three series of indirect tensile tests, the Brazilian test, the flattened Brazilian (FB) test and the ring test, were performed in order to determine the indirect maximum tensile stress of Dionysos marble. A number of circular disc specimens (D = 54 mm) was prepared by coring Dionysos marble cubes normal to the plane of transverse isotropy. Different sets of circular discs were prepared by varying the loading angle la and the internal diameter for the FB test and ring test respectively. All specimens were prepared by following the ISRM suggested methods and the load was applied using a stiff 1600 kN MTS hydraulic testing machine and a 500 kN load cell. This paper focuses on the comparison of the indirect maximum tensile stress resulting from the three different tests and the calculation of the theoretical and experimental coefficient k for the FB test and ring test. The coefficient k is a function of the loading angle la and the ratio q (internal to external diameter) for the FB test and the ring test respectively.