TY - CONF A1 - Kruschwitz, Sabine T1 - SIP responses of building materials, investigation of correlations with specific surface and dominant pore throat size T2 - 3rd International workshop on induced polarization (Proceedings) N2 - Many damage processes in building stones are driven by moisture ingress and subsequent decay due to solving, blistering or different types of corrosion. Hence, measuring moisture and/or any material property that is connected to the absorption/desorption behaviour of a porous medium is helpful for building engineers concemed with Conservation or restoration. Since the SEP method is sensitive to both the amount and chemistry of a pore fluid and pore space properties ist applicability and practical use as a non-destructive testing tool for moisture damages is studied at BAM. T2 - 3rd International workshop on induced polarization CY - Ile d'Oléron, France DA - 06.04.2014 KW - Spectral induced polarization KW - Sandstone KW - Building material KW - Pore throat sizes PY - 2014 SP - 136 EP - 137 AN - OPUS4-31175 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kruschwitz, Sabine A1 - Halisch, M. A1 - Prinz, Carsten A1 - Weller, Andreas A1 - Müller-Petke, M. A1 - Dlugosch, R. T1 - Towards a better understanding of electrical relaxation T2 - Proceedings of the Annual Symposium of the Society of Core Analysts (SCA) N2 - Other than commonly assumed the relaxation times observed in the electrical low-frequency range (1 mHz – 40 kHz) of natural porous media like sandstones and tuff stones cannot be directly related to the dominant (modal) pore throat sizes, measured (e.g.) with mercury intrusion porosimetry (MIP). Working with a great variety of sandstones from very different origins and featuring great variations in textural and chemical compositions as well as in geometrical pore space properties, it was observed that particularly samples with narrow pore throats were characterized by long (low-frequency) relaxations. These, however, can (following the current theories) be rather explained by long “characteristic length scales” in these media or low diffusion coefficients along the electrical double layer. However, there is no straightforward way (or single approved method) of getting reliable numbers for properties such as the lengths of pore throats, the diameter and length of the wide pores and their respective distributions. Consequently we follow a multi-methodical approach and combine the benefits of MIP, micro-computed tomography (μ-CT) and nuclear magnetic resonance (NMR) to achieve much deeper insight due to the different resolutions and sensitivities to either pore constrictions (throats) or wide pores. This helps us to understand, whether the observed electrical relaxation phenomena actually depend on geometric length scales or rather on other properties such as chemical composition, clay content, clay type or cation exchange capacity. In this paper, we showcase selected results of a systematic study of a total of 16 sandstones and three tuffs. Findings and the particular advantage of the used method combination are discussed and shown in detail for a representative sample selection. T2 - Annual Symposium of the Society of Core Analysts (SCA) CY - Vienna, Austria DA - 28.08.2017 KW - Electrical relaxation KW - Complex resistivity KW - Spectral induced polarization KW - Nuclear magnetic resonance KW - Mercury intrusion porosimetry KW - Pore size distribution KW - Sandstone PY - 2017 VL - SCA2017-080 SP - 1 EP - 9 AN - OPUS4-42599 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -