TY - CONF A1 - Pirskawetz, Stephan A1 - Menningen, J. A1 - Siegesmund, S. ED - Siegesmund, S. ED - Middendorf, B. T1 - Acoustic emissions - Insights into the decay mechanisms of thermally treated marbles N2 - Since ancient times, marble has been the preferred material for monuments, sculptures, Ornaments and architecture. Though the stone is often a Chosen material, long-term exposure of marble results in cumulative deterioration of the rock fabric. The rate and extent of deterioration depends on the rock fabric and the climatic conditions. Besides the thermal vulnerability of marble, a combination of thermal and hygric fluctuation accelerates the deterioration process. The weathering sensitivity of marbles can be characterised by the irreversible length change of samples after heating under thermohygric conditions as residual strain. This residual strain is a non-reversible deterioration and caused by microcracking induced by a pronounced anisotropy of the thermal dilatation coefficient of calcite. In brittle materials like marble, cracking and crack growth or friction on crack surfaces are accompanied by release of acoustic waves. The analysis of these acoustic emissions can give a deeper insight into the deterioration mechanism of marble. In this study, acoustic emissions of thermohygric treated marble were analysed and correlated with ultrasonic velocities, thermal dilatation and residual strains. Therefore, different types of calcitic marble were cyclically heated from 20 °C to 90 °C and after equilibration of the samples cooled down again to 20 °C. While the first cycles were performed under dry conditions, the following were executed in a humid environment. The analysis of acoustic emissions enables one to determine when cracking occurs during the thermal treatment. It is also possible to differentiate microcracking from internal friction. Furthermore, the evolution of Deterioration can be estimated based on ultrasonic velocities. The combination of acoustic Methods and strain measurement gives an insight into the disintegration mechanism and Supports the development of prevention strategies. T2 - 14th International Congress on the Deterioration and Conservation of Stone CY - Göttingen, Germany DA - 07.09.2020 KW - Marble KW - Weathering sensitivity KW - Cracking KW - Acoustic emission KW - Residual strain PY - 2020 SN - 978-3-96311-172-3 SP - 185 EP - 190 PB - mdv Mitteldeutscher Verlag GmbH CY - Halle (Saale) AN - OPUS4-51964 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -