MATERIALS TESTE granite

The specific gravity or density of a substance is constant for all pure specimens of that material. Synthetics or natural mixtures, like rocks (granite, sandstone, etc.), are not consistent because the component substances within them vary in type and amount. Specific gravity is a simple test, but since it requires the object to be immersed in water, it should be used only on homogeneous materials known to be insoluble. 

In this paper, we provided the rationale and definition of a benchmark test called BMTl to look at the implications of THM couplings on safety parameters in the near field of a hypothetical repository. This hypothetical repository possesses composite features since it is based on a Japanese design, with a Japanese bentonite used as buffer material and the heat output characteristics of Japanese spent fuel. However, the permeability and strength characteristics of the rock mass are based on typical properties of granites of the Canadian Shield. 

Equally important to the two- and three-sensor methods is that the common seismic signals be coherent among all instruments in the test. As discussed, this can be done by installing the instruments in a quiet vault on a granite slab or other stiff material to increase the coherence among sensors. Care should also be taken to reduce the influence on instruments under test from local non-seismic noise sources such as pressure or temperature variations and that adequate thermal settling time be provided before testing. 

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