Estimation of the tensile elastic modulus using Brazilian disc by applying diametrically opposed concentrated loads

• Published in: International journal of rock mechanics and mining sciences (Oxford, England : 1997) England : 1997), 2009-04, Vol.46 (3), p.568-576
• Main Authors: Jianhong, Ye, Wu, F.Q., Sun, J.Z.
• Format: Article
• Language: English
• Subjects: Applied sciences; Brazilian disc; Brazilian test; Buildings. Public works; Exact sciences and technology; Geotechnics; Soil mechanics. Rocks mechanics; Splitting test; Stress analytic solution; Tensile elastic modulus; Test method
• ISSN: 1365-1609; 1873-4545
• DOI: 10.1016/j.ijrmms.2008.08.004

The tensile elastic modulus E t of a rock is different from the compressive elastic modulus E c, due to inhomogeneity and microcracks. There is no convenient method to obtain E t except using direct tension tests. However, the direct tension test for rock materials is difficult to perform, because of stress concentrations, and the difficulty of preparing specimens. We have developed a new method to determine E t of rock materials easily and conveniently. Two strain gauges are pasted at the center part of a Brazilian disc's two side faces along the direction perpendicular to the line load to record tensile strain, and a force sensor is used to record the force applied; then the stress–strain curve can be obtained; finally the E t can be calculated according to those related formulas which are derived on the basis of elasticity theory. Our experimental results for marble, sandstone, limestone and granite indicate that E t is less than E c, and their ratio is generally between 0.6 and 0.9.