Abstract According to electron microscopy scanning experiments,it is found that slate has significant blasto-stratification structures and plate cleavages structure. As a result,mechanical characteristics of slate can be revealed by Brazilian disc splitting tests. Based on the disc splitting tests under seven different kinds of bedding angles θ,three kinds of failure forms of disc can be obtained as follows:pure tensile failure when the bedding angle ?<45°,shearing failure when the bedding angle ?>75°,and both tensile and shearing failure when the bedding angle ? is between 45° and 75°. Meanwhile,Because of the impact of internal bedding structure on the slate,tensile strength of the slate gradually decreases with the bedding angle θ varying from 0° to 90°. Moreover,the bedding angle has a slight influence on the elastic modulus and Poisson?s ratio perpendicular to the isotropic plane;and the elastic modulus perpendicular to the isotropic plane is slightly smaller than that of the isotropic plane.
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Received: 15 September 2011
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