TY - GEN A1 - Stephan, H. A1 - Gloe, K. A1 - Kraus, Werner A1 - Spies, H. A1 - Johannsen, B. A1 - Wichmann, K. A1 - Reck, Günter A1 - Chand, D. K. A1 - Bharadwaj, P. K. A1 - Müller, U. A1 - Müller, W. M. A1 - Vögtle, F. ED - Moyer, B. A. T1 - Binding and extraction of pertechnetate and perrhenate by azacages T2 - Symposium Fundamentals and Applications of Anion Separations ; American Chemical Society national meeting CY - Chicago, IL, USA DA - 2001-08-25 PY - 2004 SN - 0-306-47911-7 SP - 151 EP - 168 PB - Kluwer Acad./Plenum Publ. CY - New York, NY AN - OPUS4-3667 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Steinbeck, Christoph A1 - Jung, Nicole A1 - Bach, Felix A1 - Neumann, Steffen A1 - Herres-Pawlis, Sonja A1 - Liermann, Johannes A1 - Koepler, Oliver A1 - Bannwarth, Christoph A1 - Bender, Theo A1 - Bocklitz, Thomas A1 - Boehm, Franziska A1 - Bonatto Minella, Christian A1 - Biedermann, Frank A1 - Brack, Werner A1 - Cunha, Ricardo A1 - Czodrowski, Paul A1 - Eberl, Franziska A1 - Engel, Thomas A1 - Engstfeld, Albert A1 - Fischer, Tillmann G. A1 - Friedrich, Pascal A1 - Glorious, Frank A1 - Golub, Benjamin A1 - Grathwol, Christoph A1 - Haag, Rainer A1 - Hunold, Johannes A1 - Jacob, Christoph A1 - Johannsen, Jochen A1 - Jollife, John A1 - Kast, Stefan A1 - Kettner, Carsten A1 - Kuhn, Stefan A1 - Lanza, Giacomo A1 - Lisec, Jan A1 - Manolikakes, Georg A1 - Mata, Ricardo A1 - Meiler, Jens A1 - Müller, Matthias A1 - Müller-Pfefferkorn, Ralph A1 - Ortmeyer, Jochen A1 - Patterson, Wendy A1 - Pleiss, Jürgen A1 - Riedel, Annalisa A1 - Riedel, Jens A1 - Schatzschneider, Ulrich A1 - Schuster, Leonie A1 - Seeberger, Peter A1 - Seibert, Johann-Nikolaus A1 - Stadler, Peter A1 - Zeitler, Kirsten T1 - Proposal NFDI4Chem 2025-2030 In the National Research Data Infrastructure (NFDI) — Our Vision: All Chemists Publish FAIR Data N2 - The first funding period of NFDI4Chem established a robust foundation for research data management (RDM) in chemistry by promoting FAIR data principles and creating a cohesive infrastructure to capture well-annotated data early in the lab through electronic lab notebooks (ELNs) and making this data available in public repositories. Key achievements include standardised data formats and metadata, a federated repository environment, and improved data visibility and accessibility. Training programs and outreach have significantly increased awareness and adoption of best RDM practices. In the second funding period, the consortium aims to advance these achievements by consolidating this infrastructure, developing a model for its sustainable maintenance and operation, and fostering cultural change for its widespread adoption. Goals include ensuring seamless data workflows from laboratories to open repositories, enhancing interoperability, and supporting innovative research through AI-ready data. The work plan is organised into six task areas (TAs). TA1 (Management) provides leadership and supports all other TAs in achieving their objectives. TA2 (Smart Lab) aims to develop a fully digital research environment, including an ELN as a modular platform. This environment will support data collection, management, storage, analysis, and sharing. Integrating devices and external resources will enable seamless data transfer to repositories. TA3 (Repositories) will consolidate the repository ecosystem. The goal is to integrate repositories into a federated system for better accessibility and interoperability, ensuring long-term data availability and sustainability. TA4 (Metadata, Data Standards, and Publication Standards) focuses on developing and promoting new data and metadata standards in an international community process. This includes applying ontologies to create a semantic foundation for linking research data, making it machine-readable and enabling knowledge graphs. TA5 (Community and Training) is dedicated to fostering a cultural shift towards digital chemistry through continuous engagement, collecting requirements, and providing extensive training and support through workshops and open education resources. It will promote FAIR-compliant machine learning applications, embedding RDM into academic curricula to ensure future scientists are well-versed in these practices. TA6 (Synergies and Cross-Cutting Topics) aims to enhance collaboration across NFDI consortia and beyond. This includes developing ontologies, terminology services, the search service, and other cross-cutting solutions, integrating these developments into existing infrastructure, enabling interdisciplinary data harmonisation and fostering machine learning applications. KW - Research Data Management KW - FAIR KW - Chemistry PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-648540 DO - https://doi.org/10.3897/rio.11.e177037 SN - 2367-7163 VL - 11 SP - 1 EP - 100 PB - Pensoft Publishers AN - OPUS4-64854 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Werner T1 - Long-term pull-out resistance and materials properties of geogrids T2 - 10th International Conference on Geosynthetics CY - Berlin, Germany DA - 2014-09-22 PY - 2014 AN - OPUS4-31590 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Stephan, H. A1 - Walther, M. A1 - Fähnemann, S. A1 - Ceroni, P. A1 - Molloy, J.K. A1 - Bergamini, G. A1 - Heisig, F. A1 - Müller, C.E. A1 - Kraus, Werner A1 - Comba, P. T1 - Bispidines for dual imaging N2 - The efficient transformation of the hexadentate bispidinol 1 into carbamate derivatives yields functional bispidines enabling convenient functionalization for targeted imaging. The BODIPY-substituted bispidine 3 combines a coordination site for metal ions, such as radioactive 64CuII, with a fluorescent unit. Product 3 was thoroughly characterized by standard analytical methods, single crystal X-ray diffraction, radiolabeling, and photophysical analysis. The luminescence of ligand 3 was found to be strongly dependent on metal ion coordination: CuII quenches the BODIPY fluorescence, whereas NiII and ZnII ions do not affect it. It follows that, in imaging applications with the positron emitter 64CuII, residues of its origin from enriched 64Ni and the decay products 64NiII and 64ZnII, efficiently restore the fluorescence of the ligand. This allows for monitoring of the emitted radiation as well as the fluorescence signal. The stability of the 64CuII–3 complex is investigated by transmetalation experiments with ZnII and NiII, using fluorescence and radioactivity detection, and the results confirm the high stability of 64CuII–3. In addition, metal complexes of ligand 3 with the lanthanide ions TbIII, EuIII, and NdIII are shown to exhibit emission of the BODIPY ligand and the lanthanide ion, thus enabling dual emission detection. KW - Bispidines KW - Chelates KW - Imaging agents KW - Lanthanides KW - Radiolabeling KW - Nuclear medical application KW - Radioactive labelling KW - SPECT PY - 2014 DO - https://doi.org/10.1002/chem.201404086 SN - 0947-6539 SN - 1521-3765 VL - 20 IS - 51 SP - 17011 EP - 17018 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-32320 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Werner T1 - On the determination of the chemical reduction factor for PET geogrids N2 - Data from four samples of commercially available PET geogrids (made either of yarns or bars), which were measured by BAM or other institute, are analyzed to discuss the procedure and problems of determining the chemical reduction factor RFCH associated with a certain service life. Estimates from Arrhenius extrapolation usually have very large statistical errors. The level of confidence must therefore be specified. A reliable estimate requires data from immersion tests below the glass transition temperature of PET. To extrapolate the time of reductions for each reduction factor at such low temperatures, one has to know the functional form of the mechanical degradation curve. It is shown how the degradation curve of the tensile strength may be obtained by determining the relation between increase in concentration of carboxyl end group (CEG) and decrease in tensile strength. Therefore, experimental studies to determine the chemical reduction factor should be accompanied by the measurements of the CEG concentration and the intrinsic viscosity. Furthermore, such measurements allow a non-ambiguous determination of the molecular mass. Hydrolytic molecular degradation will proceed continuously even at 20 °C with half-life of the inverse of the CEG concentration of 40–100 y. Nevertheless, small chemical reduction factors at a lifetime of 100 y are obtained with high level of confidence for materials with low initial CEG concentration and high molecular mass. This is shown by pooling data from samples with comparable CEG concentration, molecular mass and above all comparable intrinsic relation between increase in CEG concentration and decrease in strength. Therefore, the recommendation of ISO TR 20432, Table 2, for chemical reduction factors seems to be applicable to PET geogrids with index properties well below the one specified by the technical report. Whether these index properties are actually a sufficient condition to have small chemical reduction factors even at a very long service life is still an open question. The determination of chemical reduction factor should be based on aging experiments, at least for products with index properties close to the limiting values for the following reasons. (1) Even so standards are available, results of different laboratories on absolute values of CEG concentration and number averaged molecular mass differ to a certain extent. (2) Other factors, like crystallization, affect the mechanical degradation significantly. (3) There is no universally applicable form of the mechanical degradation curve. KW - Hydrolytic degradation KW - Polyester KW - Geogrid KW - Chemical reduction factor KW - Aging PY - 2014 DO - https://doi.org/10.1016/j.geotexmem.2013.12.009 SN - 0266-1144 VL - 42 IS - 2 SP - 98 EP - 110 PB - Elsevier CY - Amsterdam AN - OPUS4-30231 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Pretsch, Thorsten A1 - Jakob, Ines A1 - Müller, Werner T1 - Hydrolytic degradation and functional stability of a segmented shape memory poly(ester urethane) N2 - In order to understand the effects of water and hydrolytic ageing on semi-crystalline poly(ester urethane) and its shape memory functionality, water immersion experiments at elevated temperature have been performed on a model substance and various parameters were monitored: change of the melting/crystallisation temperatures, substantial increase in crystallinity, temperature dependence of the water diffusion coefficient and solubility, hydrogen-bonding index and phase mixing by peak deconvolution of the FT-IR carbonyl region and day-to-day tensile and thermo-mechanical cyclic tensile tests. A rising fraction of freezable water agglomerates in the polymer was found for specimens cooled from the immersion temperature. The degradation process could be divided into three phases: an induction phase, a phase of continuous degradation and a phase of accelerated degradation. Shape recovery remains fairly constant during phase one and decreases slowly during phase two. The increase in crystallinity in phase two is accompanied by an increase in shape fixing ability. KW - Shape memory polymer KW - Poly(ester urethane) KW - Thermo-mechanical properties KW - Hydrolysis PY - 2009 DO - https://doi.org/10.1016/j.polymdegradstab.2008.10.012 SN - 0141-3910 SN - 1873-2321 VL - 94 IS - 1 SP - 61 EP - 73 PB - Applied Science Publ. CY - London AN - OPUS4-18661 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Österle, Werner A1 - Müller, Urs A1 - Desplanques, Y. A1 - Bulthé, A.-L. A1 - Degallaix, G. A1 - Dmitriev, A.I. T1 - 3rd Body formation of two different brake pad materials designed for railway application T2 - 5th European Conference on Braking (JEF 2006) CY - Lille, France DA - 2006-11-08 PY - 2006 SP - 107 EP - 115 AN - OPUS4-18699 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Werner T1 - Dichtungsbahnen zur Abdichtung von Deponien und Altlasten T2 - 25. Fachtagung "Die sichere Deponie", Süddeutsches Kunststoffzentrum (SKZ) CY - Würzburg, Germany DA - 2009-02-26 PY - 2009 AN - OPUS4-19015 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Werner A1 - Jakob, Ines A1 - Li, Chunshan A1 - Tatzky-Gerth, Renate T1 - Antioxidant depletion and OIT values of high impact PP strands KW - Polypropylene KW - Stabilizers KW - Oxidative resistance KW - Antioxidant depletion KW - Oxidative induction time PY - 2009 DO - https://doi.org/10.1142/S0256767909004102 SN - 0256-7679 VL - 27 IS - 3 SP - 435 EP - 445 PB - World Scientific CY - Singapore AN - OPUS4-19458 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Müller, Werner ED - Egloffstein, T. T1 - Anforderungen an Kunststoff-Dränelemente für die langfristig sichere Entwässerung von Oberflächenabdichtungen T2 - 13. Karlsruher Deponie- und Altlastenseminar CY - Karlsruhe, Deutschland DA - 2003-09-17 KW - Geokunststoffe KW - Deponieabdichtungen KW - Beständigkeit PY - 2003 SN - 3-503-07485-6 SN - 0171-175X N1 - Serientitel: Abfallwirtschaft in Forschung und Praxis – Series title: Abfallwirtschaft in Forschung und Praxis IS - 128 SP - 107 EP - 118 PB - E. Schmidt CY - Berlin AN - OPUS4-2740 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Werner ED - Knipschild, F. T1 - Eignungsnachweis für Kunststoff-Dränelemente in Oberflächenabdichtungen T2 - 20. Fachtagung "Die sichere Deponie" CY - Würzburg, Deutschland DA - 2004-02-26 KW - Kunststoff-Dränelemente KW - Eignungsnachweis KW - Langzeitverhalten KW - Oberflächenabdichtungen PY - 2004 SP - G1 EP - G12 PB - SKZ CY - Würzburg AN - OPUS4-3221 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Müller, Werner A1 - Seeger, Stefan A1 - Thies, Martina A1 - Gerloff, Constantin ED - Floss, R. T1 - Long-Term Shear Strength of Multilayer Geosynthetics T2 - 3rd European Geosynthetics Conference "EuroGeo 3" - Geotechnical Engineering with Geosynthetics CY - Munich, Germany DA - 2004-03-01 PY - 2004 SN - 3-00-013305-4 VL - II SP - 429 EP - 434 PB - Deutsche Gesellschaft für Geotechnik CY - München AN - OPUS4-3326 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Seah, M.P. A1 - Spencer, S.J. A1 - Bensebaa, F. A1 - Vickridge, I. A1 - Danzebrink, H. A1 - Krumrey, M. A1 - Gross, Thomas A1 - Österle, Werner A1 - Wendler, E. A1 - Rheinländer, B. A1 - Azuma, Y. A1 - Kojima, I. A1 - Suzuki, N. A1 - Suzuki, M. A1 - Tanuma, S. A1 - Moon, D.W. A1 - Lee, H.J. A1 - Cho, H.M. A1 - Chen, H.Y. A1 - Wee, A. T. S. A1 - Osipowicz, T. A1 - Pan, J.S. A1 - Jordaan, W.A. A1 - Hauert, R. A1 - Klotz, U. A1 - van der Marel, C. A1 - Verheijen, M. A1 - Tamminga, Y. A1 - Jeynes, C. A1 - Bailey, P. A1 - Biswas, S. A1 - Falke, U. A1 - Nguyen, N.V. A1 - Chandler-Horowitz, D. A1 - Ehrstein, J.R. A1 - Muller, D. A1 - Dura, J.A. T1 - Critical review of the current status of thickness measurements for ultrathin SiO2 on Si - Part V: Results of a CCQM pilot study N2 - Results are reported from a pilot study under the Consultative Committee for Amount of Substance (CCQM) to compare measurements of and resolve any relevant measurement issues in, the amount of thermal SiO2 oxide on (100) and (111) orientation Si wafer substrates in the thickness range 1.5 - 8 nm. As a result of the invitation to participate in this activity, 45 sets of measurements have been made in different laboratories using 10 analytical methods: medium-energy ion scattering spectrometry (MEIS), nuclear reaction analysis (NRA), RBS, elastic backscattering spectrometry (EBS), XPS, SIMS, ellipsometry, grazing-incidence x-ray reflectrometry (GIXRR), neutron reflectometry and transmission electron microscopy (TEM). The measurements are made on separate sets of 10 carefully prepared samples, all of which have been characterised by a combination of ellipsometry and XPS using carefully established reference conditions and reference parameters. The results have been assessed against the National Physical Laboratory (NPL) data and all show excellent linearity. The remaining data sets correlate with the NPL data with average root-mean-square scatters of 0.15 nm, half being better than 0.1 nm and a few at or better than 0.05 nm. Each set of data allows a relative scaling constant and a zero thickness offset to be determined. Each method has an inherent zero thickness offset between 0 nm and 1 nm and it is these offsets, measured here for the first time, that have caused many problems in the past. There are three basic classes of offset: water and carbonadeous contamination equivalent to ~1 nm as seen by ellipsometry; adsorbed oxygen mainly from water at an equivalent thickness of 0.5 nm as seen by MEIS, NRA, RBS and possibly GIXRR; and no offset as seen by XPS using the Si 2p peaks. Each technique has a different uncertainty for the scaling constant and consistent results have been achieved. X-Ray photoelectron spectroscopy has large uncertainties for the scaling constant but a high precision and, critically, if used correctly, has zero offset. Thus, a combination of XPS and the other methods allows the XPS scaling constant to be determined with low uncertainty, traceable via the other methods. XPS laboratories returning results early were invited to test a new reference procedure. All showed very significant improvements. The reference attenuation lengths thus need scaling by 0.986 ± 0.009 (at an expansion factor of 2) deduced from the data for the other methods. Several other methods have small offsets and, to the extent that these can be shown to be constant or measurable, then these methods will also show low uncertainty. Recommendations are provided for parameters for XPS, MEIS, RBS and NRA to improve their accuracy. KW - Calibration KW - Ellipsometry KW - GIXRR KW - Interlaboratory study KW - MEIS KW - Neutron reflectometry KW - NRA KW - RBS KW - Silicon dioxide KW - SIMS KW - XPS PY - 2004 DO - https://doi.org/10.1002/sia.1909 SN - 0142-2421 SN - 1096-9918 VL - 36 IS - 9 SP - 1269 EP - 1303 PB - Wiley CY - Chichester AN - OPUS4-5549 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Werner ED - Jost, D. T1 - Eignungsgutachten für Kunststoff-Dränelemente durch die BAM T2 - 21. Fachtagung "Die sichere Deponie" CY - Würzburg, Deutschland DA - 2005-02-09 KW - Scherfestigkeit KW - Beständigkeit KW - Geokunststoffe KW - Prüftechnik PY - 2005 SP - C1 EP - C18 PB - SKZ CY - Würzburg AN - OPUS4-7027 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Seeger, Stefan A1 - Müller, Werner A1 - Jakob, Ines A1 - Tatzky-Gerth, Renate A1 - August, Hans T1 - Anforderungen an die Schutzschicht für die Dichtungsbahnen in der Kombinationsdichtung - Teil 1: Wirksamkeit (lastverteilende Wirkung und Beständigkeit), Materialien und Prüfverfahren bei Schutzschichten PY - 1995 SN - 0027-2957 SN - 1863-9763 VL - 27 IS - 8 SP - 544 EP - 560 PB - Erich Schmidt CY - Berlin AN - OPUS4-7589 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Seeger, Stefan A1 - Müller, Werner ED - de Groot, M. T1 - Limits of stress and strain: Design criteria for protective layers for geomembranes in landfill liner systems T2 - 1st European Geosynthetics Conference (EUROGEO 1) CY - Maastricht, The Netherlands DA - 1996-09-30 PY - 1996 SN - 90-5410-836-3 SP - 153 EP - 157 PB - Balkema CY - Rotterdam AN - OPUS4-7575 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Seah, M.P. A1 - Spencer, S.J. A1 - Bensebaa, F. A1 - Vickridge, I. A1 - Danzebrink, H. A1 - Krumrey, M. A1 - Gross, Thomas A1 - Österle, Werner A1 - Wendler, E. A1 - Rheinländer, B. A1 - Azuma, Y. A1 - Kojima, I. A1 - Suzuki, N. A1 - Suzuki, M. A1 - Tanuma, S. A1 - Moon, D.W. A1 - Lee, H.J. A1 - Cho, H.M. A1 - Chen, H.Y. A1 - Wee, A. T. S. A1 - Osipowicz, T. A1 - Pan, J.S. A1 - Jordaan, W.A. A1 - Hauert, R. A1 - Klotz, U. A1 - van der Marel, C. A1 - Verheijen, M. A1 - Tamminga, Y. A1 - Jeynes, C. A1 - Bailey, P. A1 - Biswas, S. A1 - Falke, U. A1 - Nguyen, N.V. A1 - Chandler-Horowitz, D. A1 - Ehrstein, J.R. A1 - Muller, D. A1 - Dura, J.A. T1 - Ultra-thin SiO2 on Si, Part V: Results of a CCQM Pilot Study of Thickness Measurements KW - SiO2 KW - Thin films KW - Thickness KW - XPS KW - Ellipsometry KW - TEM PY - 2003 SN - 1473-2734 SP - 57 pages AN - OPUS4-4118 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Mielke, Werner A1 - Hampe, Andreas A1 - Lützow, Wolfgang A1 - Müller, Hansjörg A1 - Pastuska, Gerhard A1 - Rook, A. A1 - Schnabel, E. A1 - Sickfeld, Jürgen A1 - Tobisch, Karl A1 - Trubiroha, Peter T1 - Einsatz von Kunststoffen in Pkw - Literaturstudie PY - 1990 SN - 0937-1214 IS - 2 SP - 9 EP - 257 PB - Bundesanstalt für Straßenwesen CY - Bergisch Gladbach AN - OPUS4-11796 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Müller, Werner ED - Kuwano. J., ED - Jinicji, K. T1 - Geosynthetic drain elements for landfill cappings: Long-term water flow capacity and long-term shear strength T2 - 8th International Conference on Geosynthetics CY - Yokohama, Japan DA - 2006-09-18 KW - GCD KW - Water flow capacity KW - Shear strength KW - Long-term behaviour KW - Aging KW - Landfill cappings PY - 2006 SN - 90-5966-044-7 SP - 321 EP - 324 PB - Millpress CY - Rotterdam AN - OPUS4-14430 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Werner A1 - Tatzky-Gerth, Renate A1 - Jakob, Ines A1 - Li, Chunshan ED - Jost, D. T1 - Funktionsdauer von Kunststoff-Dränelementen für Oberflächenabdichtungen von Deponien und Altlasten T2 - 23. Fachtagung "Die sichere Deponie - Sicherung von Deponien und Altlasten mit Kunststoffen" CY - Würzburg, Deutschland DA - 2007-02-01 KW - Kunststoff-Dränelemente KW - Lebensdauer KW - Oberflächenabdichtungen PY - 2007 SP - 1 EP - 20 PB - SKZ CY - Würzburg AN - OPUS4-14539 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Müller, Werner A1 - Jakob, Ines A1 - Seeger, Stefan A1 - Tatzky-Gerth, Renate T1 - Long-term shear strength of geosynthetic clay liners N2 - Geosynthetic clay liners (GCLs) often have a sandwich-like multilayer structure, e.g. bentonite encased between two geotextile layers connected by fibers or yarns, either by needle-punching or stitch-bonding. Therefore, the internal shear strength of the GCL depends on the strength of reinforcing fiber bundles or yarns and their anchoring strength in the cover and carrier geotextiles. When used on long and steep slopes and covered with thick soil layers, the GCL is permanently exposed to a combined action of compressive and shear stress. Such load conditions are characteristic for landfill covers and the slope stability of the overall cover system in the long run strongly depends on the long-term internal shear strength of the GCL. A new test method was developed to study this long-term shear behavior. The focus was not only on creep, as it is normally done, but on aging effects. The shear test devices allow the measurement of creep curves and times-to-failure at elevated temperatures in different media (tap water and de-ionized water). In this publication, the main findings of the experiments on needle-punched GCLs with and without thermal treatment are summarized. Tap water as a test medium was essential to ensure sodium to calcium ion exchange in the bentonite layer. Under this condition extremely long test durations without failure were achieved. Sliding failure occurred when de-ionized water was used. Two failure modes were observed: brittle failure of the GCLs with thermal treatment and slow disentanglement of fiber bundles for untreated GCLs. Short-term shear strength (e.g. peel strength) is unrelated to the actual long-term shear strength, i.e. to the times-to-failure achieved in long-term shear strength test. Hence, short-term shear strength alone will not provide reliable dimensioning data for product design and choice of resins. Therefore, the often suggested approach, namely, restriction to short-term tests only and application of factors of safety, is challenged by these results. KW - Geosynthetic clay liner KW - Shear strength KW - Oxidative resistance KW - Test methods KW - Long-term testing PY - 2008 DO - https://doi.org/10.1016/j.geotexmem.2007.08.001 SN - 0266-1144 VL - 26 IS - 2 SP - 130 EP - 144 PB - Elsevier CY - Amsterdam AN - OPUS4-16710 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -