Читать книгу Monument Future - Siegfried Siegesmund - Страница 286

The deterioration mechanism of marble was studied by a combination of measurements of acoustic emission, ultrasonic velocity, thermal dilatation and residual strains. Four different types of marble were exposed to thermal fluctuations under dry and wet conditions. The results of the acoustic emission analysis show that the main damage arises during the first thermal treatment. This is confirmed by the development of residual strains and ultrasonic velocities in subsequent temperature cycles. Even under wet conditions acoustic methods detected no significant progression of deterioration. In contrast, under wet conditions a significant residual strain was observed. Apparently, the water prevents a complete closure of the cracks after cooling. This needs to be verified by further studies.