Petrograficzne uwarunkowania zmienności mechanicznych właściwości niejednorodnego strukturalnie marmuru kalcytowego

Abstract

Petrographic constraints on the mechanical properties of a structurally heterogenous calcite marble.A b s t r a c t. Due to its exceptional ornamental properties, the marble Fior di Pesco Carnico (FDP marble) is a common decorative stone applied to external and internal building elevations. The rock is characterized by a considerable structural and textural variability; however, this feature pertains only to a minor degree to its directional arrangement of anisotropy planes (i.e. lamination) being usually dependent on the non-uniform, spatial distribution of rock mineral components or some textural elements, mainly veins. As a result, the utilitarian properties of the FDP marble varies depending on the rock zone. Petrographic AGA (Adjacent Grain Analysis) investigations were carried out on samples representing various fragments of a marble slab and essential mechanical parameters of the rock were determined. It has been established that the FDP marble is deformable as a result of temperature changes (bowing) and that this feature can be explained to a significant degree by the type of contacts between calcite blasts (AGA = 6). Other highly variable marble properties include the flexural strength under the concentrated load and the breaking load at dowel hole in different places of a marble plate. It has also been shown that applying to computational project works lower values of the expected mechanical rock parameters instead of their mean values has a ensible justification, as to a large extent it secures a higher exploitation safety of the marble to be used within a building object.