Evaluation of Marble Alteration Processes

The aim of the paper consists in the study of three Romanian types of marble (Ruschita, Albesti, Carrara) with different compositions in different temperature conditions, for different periods of time. The three samples were exposed to two different types of treatments: 25 cycles of freeze-thaw (according to SR EN 12371) and 3 cycles of exposure to high temperatures (400 °C for 1 hour). Following the freeze-thaw cycles, small differences in chromatic parameters could be observed (∆E = 2.2 for Carrara Italia marble and ∆E = 7.2 for Rușchița pink marble). The freezing coefficient for all samples is low (0.016% - 0.029%). Following exposure to high temperature treatment, the samples show large differences in chromatic parameters (∆E = 43.47 for Albesti marble) and significant changes in gloss. The surface of the samples showed cracks and microcracks. Based on the results of this study, the following conclusions can be drawn: Thermal cycles can cause the mechanical disintegration of the outer part of the marble, starting from the discontinuities contained in the rock and between the faces between the different minerals that form the stone. Exposure to high temperatures will result in a loss of adhesion between the surface grains on the sample surface. The degradation processes have been investigated.