Non-destructive investigation and analysis of inner structure of rock samples by an X-ray CT is an important instrument for better insight into properties of rock materials related to the geometrical shape and arrangement of individual construction elements, the spatial distribution of pore space included. Study of migration parameters of transfer of granitic rock from micro-scale to real scale in the rock massive required the most detailed visualisation as possible of the pore space of selected granitic samples which is mostly formed by micro-cracks and thus can have crucial effect on transport properties of material. The visualisation of such structures requires minimizing dimensions of testing pieces. However, the method of preparation (shaping) of the testing samples of small dimensions can considerably affect not only their surface properties, but also their inner structure. The paper deals with the visualisation of small cracks in the structure and it compares two completely different methods of preparation of small rock testing samples, i.e. sample preparation by diamond circular saw and high-speed abrasive water jet. The effect of each technology of sample preparation on creation of secondary degradation of the near-surface zone of samples which is not caused by natural processes is examined.
Detailed analysis of inner structure of rock specimens is crucial to better understand the properties of rock materials related to the geometrical shape, arrangement of individual construction elements of the studied rock and distribution of pore space inside the rock. Absence or existence of micro-cracks which mainly form the pore space of the rock have significant impact on transport properties of the rock material. The investigation of migration parameters of transfer of granitic rock from micro-scale to real scale in the rock massive is based on as detailed visualization of the pore space of selected granitic specimens as possible. The visualization of such structures thus requires minimizing dimensions of testing pieces. Preparation (shaping) of the testing specimens of small dimensions can considerably affect not only the surface properties of the specimens, but also their inner structure.