Measurement of tensile strength of brittle rocks using a half ring shaped specimen

• Published in: Geosciences journal (Seoul, Korea) Vol. 23; no. 4; pp. 649 - 660
• Main Authors: Choi, Byung-Hee, Lee, Youn-Kyou, Park, Chulwhan, Ryu, Chang-Ha, Park, Chan
• Format: Journal Article
• Language: English
• Published: Seoul The Geological Society of Korea 01.08.2019; Springer Nature B.V; 한국지질과학협의회
• Subjects: Area; Curvature; Data; Digital Elevation Models; Earth and Environmental Science; Earth Sciences; Eruptions; Fallout; Geographic information systems; Geographical information systems; Hazard assessment; Hazards; Laboratory tests; Mitigation; Multidisciplinary research; Municipalities; Population; Rain; Rainfall; Rocks; Strength of materials; Studies; Temporal distribution; Volcanic activity; Volcanoes; 지질학; Italy; Brazilian test; half ring (HR) test; tensile strength; curved bar; semicircular bend (SCB) test
• ISSN: 1226-4806; 1598-7477
• DOI: 10.1007/s12303-018-0060-x

A tensile test using a half ring (HR) shaped specimen is attempted for the determination of the tensile strength of rock materials. The HR test is a 3-point bend test similar to the semicircular bend (SCB) test. However, the HR specimen is a curved prismatic bar. The theoretical tensile strength of this special bar can be obtained by an analytical formula derived from a basic theory of strength of materials. Owing to the eccentricity of the HR specimen, the possibility for a single tensile fracture to begin at the intended location can increase. This may give results that are more accurate than the conventional bending tests. In this paper, after the concept and formula of the HR test are introduced, its applicability to brittle rocks is investigated by FEM simulations and laboratory tests. In the processes, the theories of the Brazilian test and a special SCB test, which is an alternative to the Brazilian test, are used to examine the accuracy of the HR test.