Investigation of the Breakage Behaviour of Completely Decomposed Granite Under Shear Using X-ray Tomography

Abstract Noise reduction and extraction of microscopic details have been persistent challenges in microstructure visualization. This study monitors the breakage behavior of a reconstituted completely decomposed granite (CDG) sample within a medium-sized triaxial loading device using X-ray microtomography techniques (CT). We use a new filter, non-local means (NL-means), to denoise CT images. NL-means shows a good performance in noise reduction and edge sharpening. Microfractures within the particles are extracted by the black top-hat (BTH) transformation and introduced into particle fragmentation analysis. Changes in CDG particle morphology are analyzed by observing the evolution of aspect ratio, convexity, sphericity and roundness at different strains. We further study the degree of particle breakage with the evolution of relative breakage and relative fractal dimension.