PSI - Issue 46

A.S. Voznesenskii et al. / Procedia Structural Integrity 46 (2023) 155–161 A.S. Voznesenskii et al. / Structural Integrity Procedia 00 (2019) 000–000

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 gypsum stone with externally visible layers of carbonaceous clays (UG); and  the interface of gypsum and flint with streaks of carbonaceous clays (GUK).

Photographs of the areas around the notch show the interfaces. The photo shows a cross-section of the sample as a result of complete fracture after testing. In the fig. 4 samples of the GG group, the areas of carbonaceous clays show themselves in black. They are absent in the fig. 5 of the KK group. Gypsum-gypsum interface (GG). Specimen GG-1

a

b

c d Fig. 4. The appearance of the notch position in gypsum stone, there is a layer of flint on the right (a), view of the cross-section after the fault (b), graphs of changes in specimen deflection and force in time (c), as well as the cyclic relationship between force and specimen deflection (d). Flint-flint interface (KK). Specimen KK-4

a

b

c d Fig. 5. The appearance of the notch position at the gypsum-flint interface (a), view of the cross-section after the fault (b), graphs of the specimen deflection and force versus time (c), as well as the cyclic dependence between the specimen force and deflection (d).