TY - JOUR A1 - Hong, Shuxian A1 - Lai Wai-Lok, Wallace A1 - Wilsch, Gerd A1 - Helmerich, Rosemarie A1 - Helmerich, R. A1 - Günther, Tobias A1 - Wiggenhauser, Herbert T1 - Periodic mapping of reinforcement corrosion in intrusive chloride contaminated concrete with GPR N2 - This paper presents an experimental effort for developing a novel reinforcement corrosion monitoring technique based on Ground Penetrating Radar (GPR). Experiments were carried out to periodically monitor the accelerated reinforcement corrosion process with GPR. The data were processed in both time and time–frequency domains to investigate the tendencies of GPR signal attribute changes related with corrosion, moisture and chloride contamination. Data processing methods were proposed to visualize the reinforcement corrosion and chloride distribution with target specified signal attribute mapping. Half-Cell Potential (HCP) and Laser-Induced Breakdown Spectroscopy (LIBS) methods were employed to verify the GPR observations. KW - Reinforcement corrosion KW - Chloride contamination KW - Periodic monitoring KW - Ground penetrating radar PY - 2014 DO - https://doi.org/10.1016/j.conbuildmat.2014.06.019 SN - 0950-0618 VL - 66 SP - 671 EP - 684 PB - Elsevier Science CY - Amsterdam AN - OPUS4-31397 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Wilsch, Gerd A1 - Millar, Steven A1 - Schaurich, Dieter ED - Van Breugel, K. ED - Koenders, E.A.B. T1 - Laser induced breakdown spectroscopy (LIBS) as a tool for the investigation of aging of infrastructure N2 - The laser induced breakdown spectroscopy (LIBS) is a combination of laser ablation and optical emission spectroscopy. Due to the possibility of direct measurements on the sample surface and a minimum of required sample preparation investigations of building materials can be conducted quite fast. In combination with a scanning technique (translation stage or scanning mirrors head) the element distributions are evaluated taking in to account the heterogeneity of the material. This is a significant advantage compared to standard procedures. LIBS measurements are also time and cost saving in comparison to standard methods. The automated measurement procedures minimise the liability for errors. All elements are detectable and after calibration results can be quantified. At BAM LIBS has been successfully applied for the investigation of distribution and transport of different ions in building materials. Quantitative measurements are performed for chlorine, sodium, potassium, sulphur, lithium and hydrogen. Beside this the identification of substances and the evaluation of quantitative ratios by means of an integrated marker are possible. An overview about the principle and the possibilities of LIBS investigations of building materials is presented and typical applications are shown. The LIBS technique is on the step from laboratory application to on-site analyses. T2 - 1st Ageing of materials & structures 2014 conference CY - Delft, The Netherlands DA - 26.05.2014 KW - Concrete deterioration KW - LIBS KW - Element mapping KW - Chemical analysis KW - Heterogeneity KW - Chlorine KW - Sulphur KW - Alkali silica reaction (ASR) PY - 2014 SN - 978-94-6186-313-3 SP - 461 EP - 468 AN - OPUS4-31178 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gottlieb, Cassian A1 - Millar, Steven A1 - Günther, Tobias A1 - Wilsch, Gerd T1 - Revealing hidden spectral information of chlorine and sulfur in data of a mobile Laser-induced Breakdown Spectroscopy system using chemometrics N2 - For the damage assessment of reinforced concrete structures the quantified ingress profiles of harmful species like chlorides, sulfates and alkali need to be determined. In order to provide on-site analysis of concrete a fast and reliable method is necessary. Low transition probabilities as well as the high ionization energies for chlorine and sulfur in the near-infrared range makes the detection of Cl I and S I in low concentrations a difficult task. For the on-site analysis a mobile LIBS-system (k = 1064 nm, Epulse ≤ 3 mJ, t = 1.5 ns) with an automated scanner has been developed at BAM. Weak chlorine and sulfur signal intensities do not allow classical univariate analysis for process data derived from the mobile system. In order to improve the analytical performance multivariate analysis like PLS-R will be presented in this work. A comparison to standard univariate analysis will be carried out and results covering important parameters like detection and quantification limits (LOD, LOQ) as well as processing variances will be discussed (Allegrini and Olivieri, 2014 [1]; Ostra et al., 2008 [2]). It will be shown that for the first time a low cost mobile system is capable of providing reproducible chlorine and sulfur analysis on concrete by using a low sensitive system in combination with multivariate evaluation. KW - LIBS KW - Chemometrics KW - Building materials PY - 2017 DO - https://doi.org/10.1016/j.sab.2017.04.001 SN - 0584-8547 VL - 132 SP - 43 EP - 49 PB - Elsevier B.V. AN - OPUS4-40066 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Laser Induced Breakdown Spectroscopy - Alternative to Wet Chemistry and Micro-XRF T2 - International Symposium NDT in Civil Engineering, NDT-CE 2015 CY - Berlin, Germany DA - 2015-09-15 PY - 2015 AN - OPUS4-34432 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Quantitative Determination of Chloride-to-Cement-Concent of Concrete by Laser Induced Breakdown Spectroscopy (LIBS) T2 - CONCREEP-10, Mechanics and Physics of Creep, Shrinkage, and Durability of Concrete and Concrete Structures CY - Vienna, Austria DA - 2015-09-21 PY - 2015 AN - OPUS4-34433 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd A1 - Eichler, Thorsten A1 - Millar, Steven A1 - Gottlieb, Cassian T1 - Laser induced breakdown spectroscopy (LIBS) - alternative to wet chemistry and micro-XRF N2 - The laser induced breakdown spectroscopy (LIBS) gives an alternative to the standard techniques for the direct investigation of a building material. It utilize a high energy pulsed laser beam for ablation and vaporization of a small amount of material, a plasma is formed and the plasma radiation is investigated using optical emission spectroscopy. Due to the principal all elements are detectable during one measurement. In combination with a translation stage or scanner system the heterogeneity of concrete is considered in the results. Thus an element concentration may be correlated to the cement content. After calibration with a set of reference samples quantitative results are obtained. The system is automated and allows rapid measurements and minimizes the possibility of errors. At BAM a laboratory LIBS system has been successful applied for the investigation of transport processes of different ions in building materials. The spatial resolution of the measurement may rich 100 μm and the frequency of the measurements is 100 Hz. The concentration of chlorine, sulfur, carbon, sodium, potassium, lithium and hydrogen where quantitatively determined. A mobile system for on-site analysis on bridges or parking decks is available. It is a tool for the estimation of the condition of concrete structures and for quality assurance during concrete repair work on-site. In these work an overview of the possibilities of LIBS for automated investigation of building materials are given. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - LIBS KW - Elemental analysis KW - Heterogeneity KW - Chlorides KW - Sulfates KW - Alkalis KW - Corrosion KW - ASR KW - Carbonation PY - 2015 SN - 1435-4934 SP - 1 EP - 5 AN - OPUS4-34676 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd A1 - Eichler, T. A1 - Millar, Steven A1 - Gottlieb, Cassian T1 - Quantitative determination of chloride-to-cement content of concrete by laser-induced breakdown spectroscopy (LIBS) N2 - Laser-induced breakdown spectroscopy (LIBS) is a combination of plasma generation on the sample surface by a high power laser pulse and optical emission spectroscopy (OES). It is a direct measurement method without an extensive sample preparation. Concrete is a multi phase system. With LIBS it is possible to distinguish the different phases and based on that to correlate the chloride content to the cement mass. This is done by scanning the surface with a resolution of up to 0.1 mm. The high measurement frequency of 100 Hz or even higher allows the in-situ visualization of the chloride content over the measured area. With a calibration a quantification of chloride concentration is possible. As an example the LIBS measurement on a 50 mm by 70 mm area with a resolution of 0.5 mm and the visualization of the chloride distribution takes only 10 minutes. Additionally it is possible to evaluate the carbonation depth from the same measurement. Examples of practical application to determine the chloride-to-cement-content on concrete samples are presented. The possibilities and the limitations of LIBS are discussed. T2 - CONCREEP 10 - Mechanics and physics of creep, shrinkage, and durability of concrete and concrete structures CY - Vienna, Austria DA - 21.09.2015 KW - LIBS KW - Chlorides KW - Carbonation KW - Heterogeneity KW - Quantitative concentration KW - 2D-map PY - 2015 SP - 815 EP - 822 AN - OPUS4-34677 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gottlieb, Cassian A1 - Millar, Steven A1 - Grothe, S. A1 - Wilsch, Gerd T1 - 2D evaluation of spectral LIBS data derived from heterogeneous materials using cluster algorithm N2 - Laser-induced Breakdown Spectroscopy (LIBS) is capable of providing spatially resolved element maps in regard to the chemical composition of the sample. The evaluation of heterogeneous materials is often a challenging task, especially in the case of phase boundaries. In order to determine information about a certain phase of a material, the need for a method that offers an objective evaluation is necessary. This paper will introduce a cluster algorithm in the case of heterogeneous building materials (concrete) to separate the spectral information of non-relevant aggregates and cement matrix. In civil engineering, the information about the quantitative ingress of harmful species like Cl−, Na+ and SO2−4 is of great interest in the evaluation of the remaining lifetime of structures (Millar et al., 2015; Wilsch et al., 2005). These species trigger different damage processes such as the alkali-silica reaction (ASR) or the chloride-induced corrosion of the reinforcement. Therefore, a discrimination between the different phases, mainly cement matrix and aggregates, is highly important (Weritz et al., 2006). For the 2D evaluation, the expectation-maximizationalgorithm (EM algorithm; Ester and Sander, 2000) has been tested for the application presented in this work. The method has been introduced and different figures of merit have been presented according to recommendations given in Haddad et al. (2014). Advantages of this method will be highlighted. After phase separation, non-relevant information can be excluded and only the wanted phase displayed. Using a set of samples with known and unknown composition, the EM-clustering method has been validated regarding to Gustavo González and Ángeles Herrador (2007). KW - LIBS KW - Concrete KW - EM-clustering KW - Heterogeneity PY - 2017 DO - https://doi.org/10.1016/j.sab.2017.06.005 SN - 0584-8547 VL - 2017 IS - 134 SP - 58 EP - 68 PB - Elsevier B.V. AN - OPUS4-40644 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Taffe, Alexander A1 - Schaurich, Dieter A1 - Wilsch, Gerd A1 - Weritz, Friederike ED - M.G. Alexander, ED - H.-D. Beushausen, ED - F. Dehn, ED - P. Moyo, T1 - Development of a portable LIBS-device for quality assurance in concrete repair T2 - 2nd International Conference on Concrete Repair, Rehabilitation and Retrofitting CY - Cape Town, South Africa DA - 2008-11-24 KW - NDT KW - Laser-induced Breakdown Spectroscopy KW - Quality assurance KW - Damage analysis KW - Concrete repair KW - Chloride KW - Sulphate PY - 2009 SN - 978-0-415-46850-3 SP - 547 EP - 549 PB - CRC Press CY - Boca Raton AN - OPUS4-18601 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd A1 - Molkenthin, André A1 - Schaurich, Dieter A1 - Taffe, Alexander A1 - Weritz, Friederike T1 - Chlorid- und Sulfatanalyse mit LIBS - vom Laborverfahren zum Baustellengerät T2 - Fachtagung Bauwerksdiagnose 2008 - Praktische Anwendungen Zerstörungsfreier Prüfungen und Zukunftsaufgaben CY - Berlin, Deutschland DA - 2008-02-21 KW - LIBS KW - Beton KW - Bewehrungskorrosion KW - Chlorid KW - Sulfat PY - 2008 SN - 978-3-940283-08-5 N1 - Serientitel: Berichtsband der Deutschen Gesellschaft für Zerstörungsfreie Prüfung – Series title: Berichtsband der Deutschen Gesellschaft für Zerstörungsfreie Prüfung IS - 112 SP - 1 EP - 8 PB - Deutsche Gesellschaft für Zerstörungsfreie Prüfung CY - Berlin AN - OPUS4-18653 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Bruns, M. A1 - Raupach, M. A1 - Balzer, H. A1 - Gehlen, D. A1 - Noll, R. A1 - Wilsch, Gerd A1 - Taffe, Alexander ED - Susanne Gieler-Breßmer, T1 - Bildgebende Laseranalyse der Chlorid- und Sulfatverteilung in Beton T2 - 3. Kolloquium Verkehrsbauten - Schwerpunkt Parkhäuser/Brücken CY - Ostfildern, Deutschland DA - 2008-01-29 KW - LIBS KW - Beton KW - Alkali-Kieselsäure Reaktion KW - Tausalz KW - Ionen Transport PY - 2008 SN - 3-924813-72-8 IS - Tagungshandbuch 2008 SP - 1 EP - 6 AN - OPUS4-18654 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Chlorid- und Sulfatanalyse mit LIBS - vom Laborverfahren zum Baustellengerät T2 - Bauwerksdiagnose 2008, Praktische Anwendungen Zerstörungsfreier Prüfungen und Zukunftsaufgaben CY - Berlin, Germany DA - 2008-02-21 PY - 2008 AN - OPUS4-18643 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Molkenthin, André A1 - Wilsch, Gerd A1 - Weritz, Friederike A1 - Taffe, Alexander A1 - Schaurich, Dieter T1 - Visualisierung des Anionen- und Kationentransportes sowie die Quantifizierung des Cl- und S-Gehaltes mittels Laserinduzierter Breakdown-Spektroskopie (LIBS) KW - LIBS KW - Beton KW - Alkali-Kieselsäure Reaktion KW - Tausalz KW - Ionen Transport KW - Chlorid KW - Sulfat PY - 2007 SN - 0514-2946 VL - 1 SP - 30 EP - 33 CY - Wien, Österreich AN - OPUS4-18632 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Molkenthin, André A1 - Wilsch, Gerd ED - Susanne Gieler-Breßmer, T1 - Alkalimetalle - der gefährliche Partner der Chloride, neueste Erkenntnisse über Kationen aus Taumitteln T2 - 3. Kolloquium Verkehrsbauten - Schwerpunkt Parkhäuser/Brücken CY - Ostfildern, Deutschland DA - 2008-01-29 KW - LIBS KW - Beton KW - Alkali-Kieselsäure Reaktion KW - Tausalz KW - Ionen Transport PY - 2008 SN - 3-924813-72-8 IS - Tagungshandbuch 2008 SP - 1 EP - 6 AN - OPUS4-18633 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Molkenthin, André A1 - Weritz, Friederike A1 - Schaurich, Dieter A1 - Wilsch, Gerd T1 - Imaging of cation and anion transport in building materials by laser-induced breakdown spectroscopy T2 - 5th International Essen Workshop "Transport in Concrete - Nanostructure and Macrostructure" (TRANSCON 07) CY - Essen, Deutschland DA - 2007-06-11 KW - LIBS KW - Beton KW - Alkali-Kieselsäure Reaktion KW - Tausalz KW - Ionen Transport PY - 2007 SN - 978-3-931681-88-3 SP - 117 EP - 126 PB - Aedificatio Verl. CY - Essen AN - OPUS4-18634 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Weritz, Friederike A1 - Taffe, Alexander A1 - Schaurich, Dieter A1 - Wilsch, Gerd T1 - Visualization of chloride and sulfate ingress into concrete by element distributions and depth profiles determined with laser-induced breakdown spectroscopy (LIBS) T2 - 5th International Essen Workshop "Transport in Concrete - Nanostructure and Macrostructure" (TRANSCON 07) CY - Essen, Deutschland DA - 2007-06-11 KW - Laser induced breakdown spectroscopy KW - Concrete KW - Chloride KW - Sulphate KW - Depth profile PY - 2007 SN - 978-3-931681-88-3 SP - 149 EP - 158 PB - Aedificatio Verl. CY - Essen AN - OPUS4-18635 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Imaging of Cation and Anion Transport in Building Materials by Laser-Induced Breakdown Spectroscopy T2 - TRANSCON 07, 5th International Essen Workshop, Transport in Concrete, Uni Duisburg-Essen CY - Essen, Germany DA - 2007-06-11 PY - 2007 AN - OPUS4-18621 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Visualization of Chloride and Sulfate Ingress into Concrete by Element Distribution and Depth Profiles Determined with Laser-Induced Breakdown Spectroscopy (LIBS) T2 - TRANSCON 07, 5th International Essen Workshop, Transport in Concrete, Uni Duisburg-Essen CY - Essen, Germany DA - 2007-06-11 PY - 2007 AN - OPUS4-18622 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Eichler, Thorsten A1 - Isecke, Bernd A1 - Wilsch, Gerd A1 - Goldschmidt, Sebastian A1 - Bruns, M. T1 - Investigations on the chloride migration in consequence of cathodic polarisation N2 - At the Institute for Building Materials Research (ibac) in Aachen and the Federal Institute for Materials Research and Testing (BAM) in Berlin a joint research project is currently running with the aim to develop a numerical model which describes cathodic protection (CP) of reinforced concrete. Special project focus is the CP of the rear reinforcement layer. The resulting model shall include the impact of chemical alterations at the steel surface and within the adjacent concrete on the polarisation behaviour of reinforcement, which are induced by long-term application of CP. The investigations presented in this paper aim to clarify open aspects on the migration of chloride ions due to small electric fields as applied in CP of steel in reinforced concrete structures. A comparatively new method, laser induced breakdown spectroscopy (LIBS), was applied in order to determine chloride concentration profiles on laboratory specimens as one of several model parameters for a mathematical description of CP of the rear reinforcement of reinforced concrete structures. The paper concerns migration tests using non-saturated specimens under laboratory conditions at constant voltage and the application of the experimental parameters on FEM-calculations. The presented results suggest the conclusion that even comparably small electric fields, as applied in CP of steel in concrete, may lead to significant and sustainable reduction in chloride concentration at the surface of the reinforcement. KW - Steel in concrete KW - Cathodic protection KW - Pitting corrosion KW - Mild steel KW - Electrochemical impedance spectroscopy PY - 2010 DO - https://doi.org/10.1002/maco.200905560 SN - 0947-5117 SN - 1521-4176 VL - 61 IS - 6 SP - 512 EP - 517 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-21511 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Eichler, Thorsten A1 - Isecke, Bernd A1 - Wilsch, Gerd A1 - Faulhaber, Armin A1 - Weidauer, Kathleen ED - Castro-Borges, P. ED - Moreno, E.I. ED - Sakai, K. ED - Gjorv, O.E. ED - Banthia, N. T1 - The effect of chloride depletion on the corrosion state of steel in alkaline environment T2 - CONSEC`10 - 6th International conference on concrete under severe conditions CY - Mérida, Yucatán, Mexico DA - 2010-06-07 KW - Thermal sprayed zinc KW - Cathodic protection KW - Steel in concrete KW - Multi-storey-car-park PY - 2010 SN - 978-0-415-59316-8 VL - 2 SP - 1115 EP - 1121 PB - Taylor & Francis CY - London, UK AN - OPUS4-21627 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Imaging laser analysis of building materials - practical examples T2 - Quantitative Nondestructive Evaluation QNDE 2010 CY - San Diego, CA, USA DA - 2010-07-18 PY - 2010 AN - OPUS4-22846 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Wilsch, Gerd A1 - Molkentin, A. ED - Maierhofer, C. ED - Reinhardt, H.-W. ED - Dobmann, G. T1 - Laser-induced breakdown spectroscopy (LIBS) for evaluation of reinforced concrete structures KW - Laser-induced breakdown spectroscopy KW - LIBS KW - Reinforced concrete KW - Chlorine KW - On-site application PY - 2010 SN - 978-1-84569-950-5 VL - 2 IS - Chapter 9 SP - 163 EP - 184 PB - Woodhead Publ. AN - OPUS4-22901 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Taffe, Alexander A1 - Wilsch, Gerd A1 - Schaurich, Dieter ED - Gieler-Breßmer, S. T1 - Zuverlässige Bestimmung von Chloridgehalten bei der Instandsetzung tausalzgeschädigter Bauwerke T2 - 4. Kolloquium Verkehrsbauten - Schwerpunkt Parkhäuser CY - Ostfildern, Deutschland DA - 2010-02-02 KW - Zerstörungsfreie Prüfung im Bauwesen KW - Chloridanalyse KW - Betoninstandsetzung KW - Parkhäuser KW - LIBS KW - Portables LIBS KW - Tausalz PY - 2010 SN - 3-924813-82-5 IS - Kap. 11.1 SP - 405 EP - 412 CY - Ostfildern AN - OPUS4-20874 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Eichler, Thorsten A1 - Isecke, Bernd A1 - Wilsch, Gerd A1 - Goldschmidt, Sebastian A1 - Bruns, M. ED - Gieler-Breßmer, Susanne T1 - Untersuchungen zur Chloridmigration beim kathodischen Korrosionsschutz von Stahl in Beton T2 - 7. Symposium Kathodischer Korrosionsschutz von Stahlbetonbauwerken CY - Ostfildern, Deutschland DA - 2009-11-26 KW - Thermal sprayed zinc KW - Cathodic protection KW - Steel in concrete KW - Multi-storey-car-park PY - 2009 SN - 3-924813-79-5 IS - Kap. 13 SP - 23 EP - 30 AN - OPUS4-20917 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weritz, Friederike A1 - Taffe, Alexander A1 - Schaurich, Dieter A1 - Wilsch, Gerd T1 - Detailed depth profiles of sulfate ingress into concrete measured with laser induced breakdown spectroscopy N2 - Sulfate attack constitutes a major risk of chemical aggression for concrete and other building materials. Mainly structures exposed to sewage waters and sulfate rich soils are affected. The measurement of sulfate ingress is important for damage assessment previous to repair works and for quality assurance of the effectiveness of protecting coatings or during concrete removal. Laser induced breakdown spectroscopy is introduced for the quantitative measurement of sulfur contents in building materials, providing detailed depth profiles and imaging element distributions with 1 mm spatial resolution. Detailed statistical evaluation is possible due to the spatial resolution and the fast measurement of the method. Practical applications of the method for damage assessment are demonstrated for three different sewage plants. KW - Laser induced breakdown spectroscopy KW - Sulfate attack KW - Sulfur content KW - Concrete KW - Sewage plant KW - Depth profiles KW - Element distribution PY - 2009 DO - https://doi.org/10.1016/j.conbuildmat.2007.12.016 SN - 0950-0618 VL - 23 IS - 1 SP - 275 EP - 283 PB - Elsevier Science CY - Amsterdam AN - OPUS4-18426 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Isecke, Bernd A1 - Wilsch, Gerd A1 - Goldschmidt, Sebastian A1 - Bruns, M. T1 - Investigations on alterations of electrochemical parameters of steel in chloride containing concrete in consequence of cathodic polarization T2 - EUROCORR 2008 CY - Edinburgh, Scotland, UK DA - 2008-09-07 KW - LIBS KW - Cathodic Protection KW - Steel in concrete KW - Chloride Migration PY - 2008 N1 - Serientitel: EFC-Event – Series title: EFC-Event IS - 299 SP - 1 EP - 15 PB - DECHEMA CY - Frankfurt am Main AN - OPUS4-18370 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gehlen, C.D. A1 - Wiens, E. A1 - Noll, R. A1 - Wilsch, Gerd A1 - Reichling, K. T1 - Chlorine detection in cement with laser-induced breakdown spectroscopy in the infrared and ultraviolet spectral range N2 - A significant parameter to monitor the status of concrete buildings like bridges or parking garages is the determination of the depth profile of the chlorine concentration below the exposed concrete surface. This information is required to define the needed volume of restoration for a construction. Conventional methods like wet chemical analysis are time- and cost-intensive so an alternative method is developed using laser-induced breakdown spectroscopy (LIBS). The idea is to deploy LIBS to analyze drill cores by scanning the sample surface with laser pulses. Chlorine spectral lines in the infrared (IR) and ultraviolet (UV)-range were studied for chlorine detection in hydrated cement samples. The excitation energies of these spectral lines are above 9.2 eV. Hence high plasma temperatures and pulse energies in the range of some hundred millijoules are needed to induce sufficient line intensity levels at the required working distance. To further increase the line intensity and to lower the detection limit (LOD) of chlorine a measuring chamber is used where different ambient pressures and gases can be chosen for the measurements. The influences on the line intensity for pressures between 5 mbar and 400 mbar using helium as process gas and the influence of different laser burst modi like single and collinear double pulses are investigated. For the first time a LOD according to DIN 32 645 of 0.1 mass% was achieved for chlorine in hydrated cement using the UV line 134.72 nm. KW - Laser-induced breakdown spectroscopy KW - LIBS KW - Hydrated cement KW - Chlorine KW - Limit of detection PY - 2009 DO - https://doi.org/10.1016/j.sab.2009.07.021 SN - 0584-8547 SN - 0038-6987 VL - 64 IS - 10 SP - 1135 EP - 1140 PB - Elsevier CY - Amsterdam AN - OPUS4-20500 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gaft, M. A1 - Nagli, L. A1 - Fasaki, I. A1 - Kompitsas, M. A1 - Wilsch, Gerd T1 - Laser-induced breakdown spectroscopy for on-line sulfur analyses of minerals in ambient conditions KW - LIBS KW - Sulfur KW - Ambient condition KW - Mineral KW - On-line analysis PY - 2009 DO - https://doi.org/10.1016/j.sab.2009.07.010 SN - 0584-8547 SN - 0038-6987 VL - 64 IS - 10 SP - 1098 EP - 1104 PB - Elsevier CY - Amsterdam AN - OPUS4-20501 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Bollmann, K. A1 - Lyhs, P. A1 - Molkenthin, A. A1 - Wilsch, Gerd A1 - Goldschmidt, Sebastian ED - Stark, J. T1 - Untersuchung von Betonflächen mittels Laser Induced Breakdown Spectroscopy (LIBS) zur Klärung möglicher Prüfartefakte bei der Prüfung des Frost-Tausalz-Widerstandes T2 - 17. Ibausil - Internationale Baustofftagung CY - Weimar, Germany DA - 2009-09-23 KW - Beton KW - Dauerhaftigkeit KW - Abwitterung KW - CDF-Test KW - LIBS KW - Alkalien PY - 2009 SN - 978-3-00-027265-3 IS - Paper 2.101 SP - 1 EP - 6 CY - Weimar AN - OPUS4-20649 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Molkenthin, A. A1 - Wilsch, Gerd ED - Stark, J. T1 - Untersuchung der Verteilung von Anionen und Kationen in mineralischen Baustoffen mittels Laser Induced Breakdown Spectroscopy (LIBS) T2 - 17. Ibausil - Internationale Baustofftagung CY - Weimar, Germany DA - 2009-09-23 KW - Chloride KW - Alkalien KW - Verteilung KW - LIBS PY - 2009 SN - 978-3-00-027265-3 IS - Paper 2.74 SP - 1 EP - 6 CY - Weimar AN - OPUS4-20650 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd A1 - Weritz, Friederike A1 - Schaurich, Dieter A1 - Wiggenhauser, Herbert ED - Forde, M. C. T1 - Determination of chloride content in concrete structures with laser-induced breakdown spectroscopy T2 - 10th Structural Faults + Repair Conference CY - London, England, UK DA - 2003-07-01 KW - Chloride content KW - Laser induced breakdown spectroscopy (LIBS) KW - On-line results KW - Reinforced concrete PY - 2003 SN - 0-947644-53-9 PB - Engineering Technics Press CY - Edinburgh AN - OPUS4-3367 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wilsch, Gerd A1 - Schaurich, Dieter A1 - Weritz, Friederike A1 - Wiggenhauser, Herbert T1 - Laser-induced breakdown spectroscopy for on-site determination of chloride in concrete N2 - The Chloride content is an important factor which influences the durability of concrete structures. The standard methods are mostly intricate, time consuming and require a chemical laboratory. This article describes the application of a spectroscopic method, the laser-induced breakdown spectroscopy (LIBS), for the determination of Chloride contents in concrete and mortar specimens. LIBS can be used on-site, needs no sample preparation and is able to investigate rapidly a large number of different measuring points. The LIBS set-up and the experimental conditions to detect Chlorides are reported. Calibration curves are presented and the limit of detection (LOD) is determined. Results measured on different concrete cores are presented and compared with the results of standard chemical methods. T2 - 6th International Symposium Non-Destructive Testing in Civil Engineering (NDT-CE) CY - Berlin, Germany DA - 2003-09-16 PY - 2003 UR - http://www.ndt.net/article/ndtce03/papers/v011/v011.htm SN - 3-931381-49-8 SP - 1(?) EP - 11(?) PB - DGZfP CY - Berlin AN - OPUS4-3368 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Weritz, Friederike A1 - Wilsch, Gerd A1 - Schaurich, Dieter A1 - Wiggenhauser, Herbert T1 - Laser Induced Breakdown Spectroscopy as a tool for the characterization and sorting of concrete waste material in view of high-order re-use N2 - The high amount of building waste material requires innovative strategies for high-order re-use of the material. With Laser Induced Breakdown Spectroscopy (LIBS) both the elemental composition of building materials and trace elements can be determined with a real-time measurement, even on-site and in a harsh industrial environment. We present the experimental data on heavy metal detection in the ppm concentration range, as well as calibration curves. Further on we demonstrate the characterization of cement and concrete concerning the main components by means of Rankin diagrams. We suggest an implementation of LIBS in the processing of building waste materials to allow a high-order re-use. T2 - 6th International Symposium Non-Destructive Testing in Civil Engineering (NDT-CE) CY - Berlin, Germany DA - 2003-09-16 PY - 2003 UR - http://www.ndt.net/article/ndtce03/papers/p032/p032.htm SN - 3-931381-49-8 SP - 1(?) EP - 7(?) PB - DGZfP CY - Berlin AN - OPUS4-3369 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Laser-induced Breakdown Spectroscopy for determination of CI-, S-content in building materials T2 - 2nd Euro-Mediterranean Symposium on Laser Induced Breakdown Spectroscopy CY - Hersonissos, Greece DA - 2003-09-30 PY - 2003 AN - OPUS4-3373 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Laser-induced breakdown spectroscopy for on-site determination of chloride in concrete T2 - Non-Destructive Testing in Civil Engineering (NDT-CE 2003) CY - Berlin, Germany DA - 2003-09-16 PY - 2003 AN - OPUS4-3374 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Anwendungen der Laser Induced Breakdown Spectroscopy im Bauwesen T2 - DGZfP-Jahrestagung 2002: ZfP in Anwendung, Entwicklung und Forschung CY - Weimar, Germany DA - 2002-05-06 PY - 2002 AN - OPUS4-3301 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Application of laser induced breakdown spectroscopy for the detection of hydrophobic coatings T2 - 9th International Conference and Exhibition "Structural Faults and Repair" CY - London, England DA - 2001-07-04 PY - 2001 AN - OPUS4-3335 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Taffe, Alexander A1 - Schaurich, Dieter A1 - Weritz, Friederike A1 - Wiggenhauser, Herbert A1 - Wilsch, Gerd T1 - Ermittlung des Chloridgehaltes von Betonproben mit Laser-Induzierter Breakdown Spektroskopie (LIBS) T2 - 1. Kolloquium "Verkehrsbauten - Schwerpunkt Parkhäuser" CY - Esslingen, Deutschland DA - 2004-01-27 PY - 2004 SP - 651 EP - 657 PB - Techn. Akad. Esslingen CY - Esslingen AN - OPUS4-4402 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Taffe, Alexander A1 - Wilsch, Gerd A1 - Schaurich, Dieter A1 - Weritz, Friederike T1 - Einsatz der Laser-Induzierten Breakdown Spektroskopie (LIBS) im Bauwesen - Teil 1: Verfahrensbeschreibung und Durchführung von Zementanalysen PY - 2004 UR - http://www.ernst-und-sohn.de/zeitschriften/artikelrecherche/index.php?zs=bst&t=Beton-+und+Stahlbetonbau+1970-heute+%28erscheint+monatlich%29&sort=hjd&page=1&bp=&bt=&bst=bst&mw=&dibt=&st=&bst_jahr=2004&bst_heft=8&absenden=%5BAuswahl+anzeigen%5D SN - 0005-9900 SN - 1437-1006 VL - 99 IS - 8 SP - 693 EP - 694 PB - Ernst CY - Berlin AN - OPUS4-4403 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Taffe, Alexander A1 - Wilsch, Gerd A1 - Schaurich, Dieter A1 - Weritz, Friederike T1 - Einsatz der Laser-Induzierten Breakdown Spektroskopie (LIBS) im Bauwesen - Teil 2: Ermittlung von bauschädlichen Salzen PY - 2004 UR - http://www.ernst-und-sohn.de/zeitschriften/artikelrecherche/index.php?zs=bst&t=Beton-+und+Stahlbetonbau+1970-heute+%28erscheint+monatlich%29&sort=hjd&page=1&bp=&bt=&bst=bst&mw=&dibt=&st=&bst_jahr=2004&bst_heft=8&absenden=%5BAuswahl+anzeigen%5D SN - 0005-9900 SN - 1437-1006 VL - 99 IS - 9 SP - 761 EP - 762 PB - Ernst CY - Berlin AN - OPUS4-4404 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Weritz, Friederike A1 - Wilsch, Gerd ED - Cziesielski, E. T1 - Einsatz der Laser-Induzierten Breakdown Spektroskopie (LIBS) zur Bestimmung des Chloridgehaltes in Beton KW - LIBS KW - Spektroskopie KW - Chlorid-Bestimmung KW - Beton KW - Tiefenprofil PY - 2004 SN - 3-433-01705-0 SP - 393 EP - 397 PB - Ernst CY - Berlin AN - OPUS4-6065 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wilsch, Gerd A1 - Weritz, Friederike ED - Cziesielski, E. T1 - Anwendung der Laser-Induzierten Breakdown Spektroskopie (LIBS) im Bauwesen KW - LIBS KW - Spektroskopie KW - Beton KW - Zementanalyse PY - 2004 SN - 3-433-01705-0 SP - 386 EP - 393 PB - Ernst CY - Berlin AN - OPUS4-6066 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wilsch, Gerd A1 - Weritz, Friederike A1 - Schaurich, Dieter A1 - Wiggenhauser, Herbert T1 - Determination of chloride content in concrete structures with laser-induced breakdown spectroscopy N2 - An important criterion for the evaluation of reinforced concrete structures is the measurement of the chloride content. This will normally be done by time consuming standard chemical methods. We propose the application of a spectroscopic technique, the laser-induced breakdown spectroscopy (LIBS), which provides the advantages of a fast measurement, the potential for on-site application and the possibility to investigate a wide range of different measuring points. The surface can be scanned, or depth profiles are available from cores. Measurements can be performed directly on the sample surface and the results are available in near real time. We present LIBS results measured on concrete cores as well as on grinded and pressed material in comparison with the results of standard chemical methods. The optimum LIBS set-up and the experimental conditions to detect and measure chlorine in building materials are reported. The limits of detection were determined and calibration curves were measured. KW - Chloride content KW - Reinforced concrete KW - Laser-induced breakdown spectroscopy KW - Near real time results KW - Non-destructive testing PY - 2005 DO - https://doi.org/10.1016/j.conbuildmat.2005.06.001 SN - 0950-0618 VL - 19 IS - 10 SP - 724 EP - 730 PB - Elsevier CY - Oxford AN - OPUS4-10830 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wilsch, Gerd A1 - Schaurich, Dieter A1 - Wöstmann, Jens A1 - Wiggenhauser, Herbert T1 - Anwendungen der Laser Induced Breakdown Spectroscopy im Bauwesen N2 - Zusammenfassung Die Laser Induced Breakdown Spectroscopy (LIBS) ist eine analytische Methode mit der die Elementverteilung auf der Oberfläche von Proben orts- und tiefenaufgelöst ermittelt werden kann. Ein intensiver, infraroter Laserstrahl wird auf die Oberfläche fokussiert. Durch die hohe Energiedichte werden einige Mikrogramm Material verdampft und ein Plasma gebildet. Bei der Ausdehnung und Abkühlung des Plasmas wird die charakteristische Fluoreszenz der verdampften Elemente abgestrahlt und mit spektroskopischen Mitteln analysiert. Die Empfindlichkeit der Methode liegt im ppm-Bereich, die typische Messgenauigkeit beträgt einige Prozent. Die Ergebnisse liegen quasi on-line vor, es ist keine Probenpräparation notwendig und die Apparatur ist vor Ort einsetzbar. Im Artikel werden Anwendungen der LIBS zur Untersuchung von Baustoffen beschrieben. Die Ergebnisse der Ermittlung der Salzverteilung in Baustoffen, der Untersuchung der Betonzusammensetzung und dem Nachweis von hydrophobierten Schichten auf unterschiedlichen Baustoffen werden vorgestellt. T2 - Jahrestagung Zerstörungsfreie Materialprüfung 2002 CY - Weimar, Deutschland DA - 2002-05-06 KW - On-line Elementanalyse KW - Salzverteilung KW - Betonzusammensetzung KW - Hydrophobierung PY - 2002 UR - http://www.ndt.net/article/dgzfp02/papers/p29/p29.htm SN - 3-931381-39-0 N1 - Serientitel: Berichtsband / Deutsche Gesellschaft für zerstörungsfreie Prüfung e. V. – Series title: Berichtsband / Deutsche Gesellschaft für zerstörungsfreie Prüfung e. V. IS - 80-CD PB - DGZfP CY - Berlin AN - OPUS4-2216 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Determination of Chloride Content in Concrete Structures with Laser-Induced Breakdown Spectroscopy T2 - 10th International Conference and Exhebition, Structural Faults + Repair 2003 CY - London, England DA - 2003-07-01 PY - 2003 AN - OPUS4-3835 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weritz, Friederike A1 - Schaurich, Dieter A1 - Taffe, Alexander A1 - Wilsch, Gerd T1 - Effect of heterogeneity on the quantitative determination of trace elements in concrete N2 - Laser-induced breakdown spectroscopy has been used for quantitative measurement of trace elements, e.g. sulfur and chlorine, in concrete. Chloride and sulfate ions have a large effect on the durability of concrete structures, and quantitative measurement is important for condition assessment and quality assurance. Concrete is a highly heterogeneous material in composition and grain-size distribution, i.e. the spatial distribution of elements. Calibration plots were determined by use of laboratory-made reference samples consisting of pressings of cement powder, hydrated cement, cement mortar, and concrete, in which the heterogeneity of the material is increasing because of the aggregates. Coarse aggregate and cement paste are distinguishable by the intensity of the Ca spectral lines. More advanced evaluation is necessary to account for the effect of the fine aggregate. The three series of reference samples enable systematic study of the effects of heterogeneity on spectral intensity, signal fluctuation, uncertainty, and limits of detection. Spatially resolved measurements and many spectra enable statistical evaluation of the data. The heterogeneity has an effect on measurement of the sulfur and chlorine content, because both occur mainly in the cement matrix. Critical chloride concentrations are approximately 0.04% (m/m). The chlorine spectral line at 837.6 nm is evaluated. The natural sulfur content of concrete is approximately 0.1% (m/m). The spectral line at 921.3 nm is evaluated. One future application may be simultaneous determination of the amount of damaging trace elements and the cement content of the concrete. KW - LIBS KW - Heterogeneity KW - Concrete KW - Chlorine KW - Sulfur PY - 2006 DO - https://doi.org/10.1007/s00216-006-0362-0 SN - 1618-2642 SN - 1618-2650 VL - 385 IS - 2 SP - 248 EP - 255 PB - Springer CY - Berlin AN - OPUS4-12206 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Weritz, Friederike A1 - Taffe, Alexander A1 - Schaurich, Dieter A1 - Wilsch, Gerd T1 - Praktische Anwendungen der Laser-Induzierten Plasma Spektroskopie im Bauwesen - Fallstudien an einem Klärbehälter und einem Parkdeck T2 - DGZfP-Fachtagung Bauwerksdiagnose "Praktische Anwendungen Zerstörungsfreier Prüfungen" CY - Berlin, Deutschland DA - 2006-02-22 KW - LIBS KW - Beton PY - 2006 SN - 3-931381-71-4 SP - 1(?) EP - 9(?) PB - DGZfP CY - Berlin AN - OPUS4-12208 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weritz, Friederike A1 - Ryahi, Solh A1 - Schaurich, Dieter A1 - Taffe, Alexander A1 - Wilsch, Gerd T1 - Quantitative determination of sulfur content in concrete with laser-induced breakdown spectroscopy N2 - Laser-induced breakdown spectroscopy has been employed for the investigation of the sulfur content of concrete. Sulfur compounds are a natural but minor component in building materials. The ingress of sulfates or sulfuric acid constitutes a major risk of chemical aggression for concrete. There is a need for a fast method, which can be used on-site and is able to investigate a wide range of different measuring points, so that damages can be characterized. For quantitative determination the sulfur spectral line at 921.3 nm is used. The optimum ambient atmosphere has been determined by comparison of measurements accomplished under air, argon and helium atmosphere. Reference samples have been produced and calibration curves have been determined, the results of LIBS measurements are compared with results from chemical analysis. Defining a limit for the intensity ratio of a calcium and a oxygen spectral line can reduce the influence of the heterogeneity of the material, so that only spectra with a high amount of cementitious material are evaluated. Depth profiles and spatial resolved sulfur distributions are presented measured on concrete cores originating from a highly sulfate contaminated clarifier. KW - Laser-induced breakdown spectroscopy KW - Sulfur content KW - Building materials KW - Heterogeneity KW - Depth profiles PY - 2005 DO - https://doi.org/10.1016/j.sab.2005.05.036 SN - 0584-8547 SN - 0038-6987 VL - 60 IS - 7-8 SP - 1121 EP - 1131 PB - Elsevier CY - Amsterdam AN - OPUS4-10997 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Taffe, Alexander A1 - Schaurich, Dieter A1 - Weritz, Friederike A1 - Wilsch, Gerd ED - Alexander, M. T1 - Chloride and sulphate content in concrete with Laser-Induced Breakdown Spectroscopy (LIBS) T2 - International Conference on Concrete Repair, Rehabilitation and Retrofitting (ICCRRR) CY - Cape Town, South Africa DA - 2006-11-21 KW - LIBS KW - Chloridgehalt KW - Schwefelgehalt KW - Bauwerksuntersuchung KW - Zustandsermittlung KW - Betoninstandsetzung KW - Betonschäden PY - 2006 SN - 0-415-39654-9 N1 - Serientitel: Balkema proceedings and monographs in engineering, water and earth sciences – Series title: Balkema proceedings and monographs in engineering, water and earth sciences SP - 519 EP - 524 PB - Taylor & Francis CY - London AN - OPUS4-11682 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Weritz, Friederike A1 - Taffe, Alexander A1 - Schaurich, Dieter A1 - Wilsch, Gerd ED - Cruz, P. ED - Frangopol, D. T1 - Chloride determination for condition assessment and quality assurance by LIBS T2 - 3rd International Conference on Bridge Maintenance, Safety and Management - "Bridge Maintenance, Safety, Management, Life-Cycle Performance and Cost" CY - Porto, Portugal DA - 2006-07-16 KW - LIBS KW - Chloride KW - Concrete PY - 2006 SN - 0-415-40315-4 N1 - Serientitel: Balkema proceedings and monographs in engineering, water and earth sciences – Series title: Balkema proceedings and monographs in engineering, water and earth sciences SP - 333 EP - 334 PB - Taylor & Francis CY - London AN - OPUS4-13716 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Taffe, Alexander A1 - Schaurich, Dieter A1 - Weritz, Friederike A1 - Wilsch, Gerd T1 - Laser-Induced Breakdown Spectroscopy (Libs) in Civil Engineering T2 - 9th European Conference on NDT : ECNDT Berlin 2006 CY - Berlin, Germany DA - 2006-09-25 KW - NDT-EC KW - LIBS KW - Spectroscopy KW - Concrete damages KW - Chloride KW - Sulphate KW - Corrosion KW - Condition assessment KW - Quality assurance PY - 2006 SN - 3-931381-86-2 SP - 1(?) EP - 6(?) PB - European Federation for Non-Destructive Testing CY - Berlin AN - OPUS4-13690 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weritz, Friederike A1 - Schaurich, Dieter A1 - Wilsch, Gerd T1 - Detector comparison for sulfur and chlorine detection with laser induced breakdown spectroscopy in the near-infrared-region N2 - Laser-induced breakdown spectroscopy has been employed for the investigation of the sulfur and chlorine content of building materials. Both, chloride and sulfate ions are major damaging species affecting the stability and lifetime of a structure. Chlorine and sulfur are mostly detected in the VUV and the NIR. In case of building materials the main elements like calcium or iron have many strong spectral lines over the whole spectral range, so that trace elements can only be detected in spectral windows unaffected from these lines. With regard to a preferably simply, robust against dust and vibrations and portable setup only the NIR spectral features are used for civil engineering applications. Most detectors, mainly CCD cameras have rapidly decreasing quantum efficiency in the NIR. Also the quantum efficiency of the photocathode of CCD-Detectors with image intensifier is decreasing in the NIR. Different CCD-detectors were tested with respect to high quantum efficiency and high dynamic range, which is necessary for simultaneous detection of weak spectral lines from trace elements and intense spectral lines from main elements. The measurements are made on reference samples consisting of cement, hydrated cement, cement mortar and concrete with well-defined amounts of the trace elements. Experimental conditions are chosen for an optimum intensity of the trace element spectral lines. The detector systems are compared by limit of detections and the signal to noise ratio. KW - LIBS KW - Sulfur KW - Chlorine KW - NIR KW - Building materials KW - Concrete KW - Detector comparison PY - 2007 DO - https://doi.org/10.1016/j.sab.2007.10.017 SN - 0584-8547 SN - 0038-6987 VL - 62 IS - 12 SP - 1504 EP - 1511 PB - Elsevier CY - Amsterdam AN - OPUS4-16507 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Isecke, Bernd A1 - Wilsch, Gerd ED - Forde, M.C. T1 - Investigations on the secondary protection mechanisms in cathodic protection applications N2 - A joint research project was accomplished by ibac and BAM with the aim to develop a numerical model of cathodic protection (CP) of reinforced concrete with a special focus on CP of the rear reinforcement layer. The model was intended to include the effects of chemical alterations within the concrete and the steel concrete interface, which are induced by long-term application of CP. The investigations presented in this paper focus on the migration of chloride ions due to small electric fields as applied during cathodic protection of steel in reinforced concrete structures and its impact on polarisation characteristics. A comparatively new method, laser induced breakdown spectroscopy (LIBS), was used to determine chloride profiles on laboratory specimens in order to investigate one of several model parameters to describe cathodic protection of the rear reinforcement of reinforced concrete structures. These investigations are described elsewhere, [1]. The paper focuses on long term polarisation tests and their impact on the charge depending cathodic polarisation behaviour of laboratory specimens. T2 - Structural faults & repair 2012 - 14th International conference and exhibition CY - Edinburgh, Scotland DA - 2012-07-03 KW - Concrete KW - Cathodic protection KW - Chloride migration KW - Corrosion KW - Steel in concrete PY - 2012 SN - 0-947664-71-7 SP - 1 EP - 6 PB - Engineering Technics Press AN - OPUS4-26413 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Laser induced breakdown spectroscopy for fast analysis of ingress profiles of ions on concrete T2 - Structural Faults & Repair 2012 - 14th International Conference and Exhibition CY - Edinburgh, Scotland DA - 2012-07-03 PY - 2012 AN - OPUS4-27411 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Mobile LIBS device for the investigation of building materials T2 - 7th International Conference on Laser Induced Breakdown Spectroskopy (LIBS 2012) CY - Luxor, Egypt DA - 2012-09-29 PY - 2012 AN - OPUS4-27416 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Laser Induced Breakdown Spectroscopy (LIBS) - alternative to wet chemistry and micro-XRF T2 - 1st International Conference on the Chemistry of Construction Materials CY - Berlin, Germany DA - 2013-10-07 PY - 2013 AN - OPUS4-29524 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - LIBS for the quantitative determination of sodium and chlorine distribution in concrete T2 - 1st International Conference on the Chemistry of Construction Materials CY - Berlin, Germany DA - 2013-10-07 PY - 2013 AN - OPUS4-29525 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Laser Induced Breakdown Spectroscopy (LIBS) - alternative for the investigation of building materials T2 - 7th Euro-Mediterranean Symposium on Laser-Induced Breakdown Spectroscopy CY - Bari, Italy DA - 2013-09-16 PY - 2013 AN - OPUS4-29526 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Mobile scanning LIBS device for the investigation of building materials T2 - 7th Euro-Mediterranean Symposium on Laser-Induced Breakdown Spectroscopy CY - Bari, Italy DA - 2013-09-16 PY - 2013 AN - OPUS4-29527 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd A1 - Schaurich, Dieter A1 - Wöstmann, Jens A1 - Wiggenhauser, Herbert T1 - Nachweis von Hydrophobierungsmitteln mit Laser Induced Breakdown Spectroscopy T2 - Fachtagung Bauwerksdiagnose - Praktische Anwendungen Zerstörungsfreier Prüfungen CY - Leipzig, Germany DA - 2001-10-25 PY - 2001 N1 - Serientitel: Berichtsband / Deutsche Gesellschaft für zerstörungsfreie Prüfung e. V. – Series title: Berichtsband / Deutsche Gesellschaft für zerstörungsfreie Prüfung e. V. IS - 76-CD PB - DGZfP CY - Berlin AN - OPUS4-1189 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd A1 - Schaurich, Dieter A1 - Wöstmann, Jens A1 - Wiggenhauser, Herbert ED - Forde, M. C. T1 - Application of laser induced breakdown spectroscopy for the detection of hydrophobic coatings T2 - 9th International Conference and Exhibition "Structural Faults and Repair" CY - London, England, UK DA - 2001-07-04 KW - LIBS KW - NDT KW - Hydrophobic Coating KW - Cement KW - Mortar KW - Brick PY - 2001 VL - 9 CY - Edinburgh AN - OPUS4-1177 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Wiggenhauser, Herbert A1 - Kind, Thomas A1 - Mielentz, Frank A1 - Strangfeld, Christoph A1 - Völker, Christoph A1 - Wilsch, Gerd T1 - Non-destructive testing in civil engineering at BAM N2 - Research and Development in Non-Destructive Testing in Civil Engineering at BAM has de-veloped over more than two decades. Highlights of present research are ultrasound phase array probes, ground penetrating radar applications for the assessment of existing structures and Laser Induced Breakdown Spec-troscopy (LIBS) to determine which chemical elements on the surface of a specimen are. RFID sensor devel-opments for wireless moisture monitoring and data fusion for the combined analysis of sensor data are fast developing areas. In addition, a selection of application cases is briefly described. T2 - Vortrag über die Aktivitäten des Fachbereichs 8.2 in der zerstörungsfreien Prüfung im Bauwesen. KW - Ultrasonic testing KW - RFID-sensors KW - Data fusion KW - Ground penetrating radar KW - LIBS PY - 2017 SP - 1 EP - 10 CY - Berlin AN - OPUS4-44132 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schultheiß, Annika L. A1 - Kruschwitz, Sabine A1 - Wilsch, Gerd A1 - Bogner, Andreas A1 - Patel, Ravi T1 - Lessons learnt on quantitative spatial chloride analysis using LIBS and μXRF N2 - Understanding chloride ingress is crucial in the context of the durability of concrete structures against corrosion. Techniques such as Laser-Induced Breakdown Spectroscopy (LIBS) and Micro X‑ray Fluorescence (µXRF) can provide a 2D representation of chloride ingress. However, obtaining quantitative data from such techniques is not a trivial task. In this study, we focus on factors such as sample preparation, measurement settings, calibration strategy, and post-processing of results which directly affect the outcome of the experiments but are rarely discussed in the literature. T2 - Rilem Annual Week 2024 CY - Toulouse, France DA - 25.08.2024 KW - Chloride ingress KW - LIBS, µXRF KW - Imaging KW - Nondestructive testing KW - Durability PY - 2024 AN - OPUS4-61663 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weise, Frank A1 - Millar, Steven A1 - Wilsch, Gerd T1 - Analyse des Tausalzeintrags in Fahrbahndeckenbetone mit neuartiger Prüftechnik T1 - Analysis of De-icing Salt in Concrete Pavement with a new type of Test Technology N2 - In den letzten Jahren sind im deutschen Bundesautobahnnetz vermehrt AKR-Schäden an Betonfahrbahndecken aufgetreten. Ursächlich hierfür ist die Verwendung alkaliempfindlicher Gesteinskörnung. Dies führt bei gleichzeitiger Anwesenheit von Wasser infolge der Exposition der Fahrbahndecke und des alkalischen Milieus durch den Einsatz alkalireicher Portlandzemente bei der Betonherstellung zu einer Alkali-Kieselsäure-Reaktion (AKR). Zusätzlich wird der AKR-Schädigungsprozess in Betonfahrbahndecken durch den externen Tausalzeintrag (primär NaCl) im Winter begünstigt. Vor diesem Hintergrund kommt der Ermittlung des Tausalzeintrags in den Fahrbahndeckenbeton eine große Bedeutung zu. Die Analyse des Tausalzeintrags erfolgte bisher ausschließlich nasschemisch an gemahlenen Bohrkernsegmenten. Nachteilig sind hierbei der relativ hohe prüftechnische Aufwand und die eingeschränkte Ortsauflösung. Der alternative Einsatz von LIBS (Laser-induced breakdown spectroscopy) eröffnet in diesem Kontext neue Möglichkeiten. So wird in diesem Beitrag anhand von Bohrkernen aus einem repräsentativen AKR-geschädigten BAB-Abschnitt exemplarisch die Vorgehensweise bei der LIBS-Analyse zur Ermittlung der Na- und Cl-Verteilung an vertikalen Schnittflächen von Bohrkernen aufgezeigt. Da der Tausalzeintrag primär über den Zementstein erfolgt, wurde der verfälschende Na-Grundgehalt der Gesteinskörnung mittels eines Ausschlusskriteriums (Ca-Gehalt) eliminiert. Vergleichend durchgeführte Cl-Mappings mit Mikroröntgenfluoreszenzanalyse sowie nasschemische Analysen belegen die Güte der durchgeführten LIBS-Messungen. Allerdings bedarf es bei der quantitativen Ermittlung des Natriumgehaltes in der Betonfahrbahndecke noch weitergehender Untersuchungen. N2 - Analysis of the intrusion of de-icing salt into concrete pavements by a novel test method In recent years the German motorway network has seen an increase in the occurrence of damage in concrete pavements. This has been caused by the use of alkali-sensitive aggregates. Given the exposure of the concrete pavement to water and the alkaline environment caused by the use of Portland cement during concrete mixing, this environment can lead to an alkali-silica reaction (ASR) process. This ASR-damage process in concrete pavements is further exacerbated by the external application of de-icing salt in winter. Against this background, the evaluation of the intrusion of de-icing salt becomes of great importance. Until now, the analysis of the intrusion of de-icing salt was carried out in a wet-chemistry process on finely ground segments of drilling cores. The disadvantages of this method are the relatively arduous testing process and the limited depth resolution. The alternative application of LIBS (laser-induced breakdown spectroscopy) offers new possibilities in this context. In this paper, the procedure for the LIBS analysis of sodium and chloride distribution on vertical cut surfaces of drilling cores taken from representative ASR-damaged concrete pavements is presented. Because the intrusion of de-icing salt takes place primarily in the cement matrix, the distorting effect of the sodium content in the aggregates was eliminated by an exclusion criteria (namely, the calcium content). The comparable chloride mappings by micro X-ray fluorescence spectroscopy and wet-chemical analysis confirm the quality of the LIBS measurements. However, additional investigations are necessary for the quantitative analysis of sodium content in concrete pavements. KW - Betonfahrbahndecke KW - Alkali-Kieselsäure-Reaktion KW - Tausalz KW - LIBS KW - MRFA KW - Nasschemie KW - ZfP PY - 2018 DO - https://doi.org/10.1002/best.201800033 SN - 0005-9900 SN - 1437-1006 VL - 113 IS - 9 SP - 656 EP - 666 PB - Wilhelm Ernst & Sohn, Verlag für Architektur und technische Wissenschaften GmbH & Co. KG CY - Berlin AN - OPUS4-46171 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Völker, Tobias A1 - Millar, Steven A1 - Strangfeld, Christoph A1 - Wilsch, Gerd T1 - Identification of type of cement through laser-induced breakdown spectroscopy N2 - The composition of concrete determines its resistance to various degradation mechanisms such as ingress of ions, carbonation or reinforcement corrosion. Knowledge of the composition of the hardened concrete is therefore helpful to assess the remaining service life of an existing structure or evaluate the damage observed during inspections. For example, for most existing concrete structures the type of cement originally used is not known and must therefore be determined afterwards. This paper presents a preliminary study on the application of laser-induced breakdown spectroscopy (LIBS) to identify the type of cement. For this purpose, ten different types of cement were investigated. For every type, three cement paste prisms were produced: (i) prisms dried, ground and pressed into tablets, (ii) prisms dried and (iii) prisms untreated. LIBS measurements were performed with a diode-pumped low energy laser (1064 nm, 3 mJ, 1.5 ns, 100 Hz) in combination with two compact spectrometers which cover the UV and NIR spectral range. A reduced subset of spectral features was used to build a classification model based on linear discriminant analysis. The results show that the classification of homogenized pressed cement powder samples provides a high accuracy, however, factors such as a different sample matrix and moisture content can affect the accuracy of the classification. The study demonstrates that LIBS is a promising tool to identify the type of cement. KW - Spectroscopy KW - LIBS KW - Cement KW - Classification KW - Identification PY - 2020 DO - https://doi.org/10.1016/j.conbuildmat.2020.120345 VL - 258 SP - 120345 PB - Elsevier Ltd. AN - OPUS4-51157 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schwarz, W. A1 - Wilsch, Gerd A1 - Katsumi, N. A1 - Ebell, Gino A1 - Völker, Tobias T1 - Ion distribution in concrete overlay, mapped by laser induced breakdown spectroscopy (LIBS), modified by an embedded zinc anode N2 - Galvanic corrosion protection by embedded zinc anodes is an accepted technique for the corrosion protection of reinforcing steel in concrete. Galvanic currents flow between the zinc anode and the steel reinforcement due to the potential difference that is in the range of a few hundred mV. The ion distribution was studied on two steel reinforced concrete specimens admixed with 3 wt.% chloride/wt. cement and galvanically protected by a surface applied EZ-anode. On both specimens, a zinc anode was embedded and glued to the concrete surface by a geo-polymer-based chloride-free binder. At one specimen, the EZ-anode was operated for 2,5 years, the EZ-anode at the other specimen was not electrically connected to the reinforcement, this specimen serves as a reference. Both specimens have been stored under identical conditions. The ion distribution between the anode (EZ-anode) and cathode (steel reinforcement) was studied by laser-induced breakdown spectroscopy (LIBS) after 7 months, 12 months, and 2,5 years. Results of the LIBS studies on the specimen with activated EZ-anode after 7 months, 12 months, and 2,5 years and of the reference specimen after 2,5 years are reported. Results show that diffusion of ions contributes to the changes in the ion distribution but migration, especially of chlorides towards the EZ-anode is significant despite the weak electric field – several hundred millivolts - generated by the galvanic current. Results show that chloride ions accumulate near the zinc-anode as in water-insoluble zinc-hydroxy chlorides - Simonkolleit. T2 - ICCRRR 2022 CY - Capetown, South Africa DA - 03.10.2022 KW - Korrosion KW - Corrosion KW - LIBS KW - Zinc PY - 2022 AN - OPUS4-55948 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd A1 - Goldschmidt, Sebastian A1 - Niederleithinger, Ernst A1 - Bienert, K. A1 - Schalk, H. A1 - Molkenthin, A. ED - Jacobsen, S. ED - Justnes, H. ED - Cepuritis, R. ED - Hornbostel, K. ED - Peng, Y. T1 - Quality control of hydrophobic coatings with an integrated marker element by laser-induced breakdown spectroscopy (LIBS) N2 - Reinforced concrete structures are affected by damage caused e. g. by freeze-thaw effects or corrosion. Most damage processes are triggered by moisture transport including soluble substances. Hydrophobie coatings can be used for prevention of such damage, but quantitative on-site quality assurance methods are so far missing. A way to overcome this problem is to integrate marker substances into the coating, which can be detected by spectroscopic methods. Different types of marker elements have been tested. It can be shown that transition metals are best suited for the task. Currently a LIBS (laser-induced breakdown spectroscopy) System is developed for the measurement of penetration depth and content of the hydrophobic coating via the marker element in the peripheral zone of concrete. T2 - ICDC 2012 - International congress on durability of concrete CY - Trondheim, Norway DA - 18.06.2012 KW - Hydrophobic coating KW - Marker element KW - Quality control KW - Depth of penetration KW - Concrete repair KW - Pitting corrosion KW - Chloride KW - Exposure KW - Freeze-taw cycles KW - Laser-induced breakdown spectroscopy KW - Hydrophobierung KW - Laser Induced Breakdown Spektroskopie KW - Qualitätskontrolle PY - 2012 SN - 978-82-8208-031-6 SP - Session B 1, 1 EP - 14 AN - OPUS4-27527 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bienert, K. A1 - Schalk, H. A1 - Molkenthin, A. A1 - Wilsch, Gerd A1 - Goldschmidt, Sebastian A1 - Niederleithinger, Ernst ED - Grantham, M. ED - Mechtcherine, V. ED - Schneck, U. T1 - Quality control of hydrophobic coatings with an integrated marker element by laser-induced breakdown spectroscopy (LIBS) N2 - Reinforced concrete structures are affected by damage, caused e.g., by freeze-thaw effects or corrosion. Most damage processes are triggered by moisture transport including soluble substances. Hydrophobic coatings can be used for prevention of such damage, but quantitative on-site quality assurance methods are so far missing. A way to overcome this problem is to integrate marker substances into the coating, which can be detected by spectroscopic methods. Different types of marker elements have been tested. It can be shown that transition metals are best suited for the task. Currently a LIBS (Laser Induces Breakdown Spectroscopy) system is developed for the measurement of penetration depth and content of the hydrophobic coating via the marker element in the peripheral zone of concrete. T2 - Concrete solutions 2011 - 4th International conference on concrete repair CY - Dresden, Germany DA - 26.09.2011 KW - Laser induced breakdown spectroscopy (LIBS) KW - Hydrophobic coating KW - Quality control KW - Depth of penetration KW - Concrete repair KW - Chloride PY - 2012 SN - 978-0-415-61-622-5 SP - 805 EP - 811 PB - Taylor & Francis CY - London AN - OPUS4-25151 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Quality control of hydrophobic coatings with an integrated marker element by laser-induced breakdown spectroscopy (LIBS) T2 - Concrete Solutions 2011, 4th International Conference on Concrete Repair CY - Dresden, Germany DA - 2011-09-26 PY - 2011 AN - OPUS4-25105 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bienert, K. A1 - Schalk, H. A1 - Molkenthin, A. A1 - Wilsch, Gerd A1 - Goldschmidt, Sebastian A1 - Niederleithinger, Ernst T1 - Qualitätskontrolle von Hydrophobierungen mit einem integrierten Markerelement durch die laser-induced breakdown spectroscopy (LIBS) N2 - Stahlbetonbauwerke sind nutzungsbedingt Umwelteinwirkungen ausgesetzt, die zu Schäden an der Konstruktion führen können. Dabei ist in erster Linie die Einwirkung von tausalzhaltigen Wässern im Winter zu nennen, die durch den Beton kapillär und über Diffusionsvorgänge aufgenommen werden. Dies fuhrt durch den Chlorideinfluss langfristig zur Korrosion der Bewehrung. Zudem leidet die Frost-Taubeständigkeit durch das Herabsetzen der Gefrierpunkttemperatur im Porenwasser. Die Folge sind Abwitterungen an der Betonoberfläche. Die meisten zerstörenden Prozesse werden durch einen Feuchtigkeitstransport ausgelöst, der lösliche Substanzen beinhaltet. Hydrophobierungen können zur Vorbeugung von solchen Schäden verwendet werden aber es gibt bisher keine Methoden zur Qualitätssicherung vor-Ort. Eine Möglichkeit der Qualitätssicherung ist, eine markierende Substanz in, die Tiefenhydrophobierung zu integrieren, die durch spektroskopische Methoden detektiert werden kann. Unterschiedliche Arten von Markerelementen wurden hierfür getestet Es konnte gezeigt werden, dass Übergangsmetalle am besten als Marker geeignet sind. Derzeit wird ein mobiles LIBS - System für die Messung der Eindringtiefe und zu hoch aufgelösten Darstellung der Wirkstoffverteilung in der Betonrandzone entwickelt. T2 - 18. Ibausil - Internationale Baustofftagung CY - Weimar, Germany DA - 12.09.2012 KW - Hydrophobierung KW - Markerelement KW - Qualitätskontrolle KW - Eindringtiefe KW - Betonreparatur KW - Lochfraßkorrosion KW - Chloride KW - Frost-Tausalz-Wechsel KW - LIBS PY - 2012 SN - 978-3-00-034075-8 VL - 2 IS - 3.07 SP - 2-0398 EP - 2-0409 AN - OPUS4-27601 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Wiggenhauser, Herbert A1 - Helmerich, Rosemarie A1 - Krause, Martin A1 - Mielentz, Frank A1 - Niederleithinger, Ernst A1 - Taffe, Alexander A1 - Wilsch, Gerd ED - Naus, D. T1 - Non-destructive Testing of Nuclear Power Plant Concrete Structures State of the Art Report N2 - Nuclear Power Plants have been in operation for ca. 50 years. Based on this experience, non-destructive testing tasks specific to thick and highly reinforced nuclear containment structures have materialized. The performance based Service life extension of existing NPPs also needs a measurement based decision to support continuing the service of the concrete part of the installations. By nature, concrete is a very durable material and any natural Deterioration processes may take a long time to become critical to the structure. The experience of more than 50 years of service limits the testing tasks to a few ones which are not yet solved. Research in NDT of concrete structures is performed by many research institutions all over the world with different technical and systematic approaches. Results are mainly obtained on laboratory specimens, sometimes additional field studies are reported. This research takes place independently without coordination and as a result, the outcomes mostly lack full comparability. Software for data analysis has become indispensable and very powerful. This part of testing needs more attention when it comes to evaluate test results. Validation of NDE solutions is becoming a critical part in concrete structure testing. Validation is by definition the proof that a customer´s requirements in the test are being met by the testing solution. This includes equipment, personnel qualification and data analysis. In the following tables, the research recommendation Validation is used in the sense, that proof of the performance of existing solutions needs to be adressed. In general, a validation methodology for NDE solutions for concrete testing in itself needs to be researched and established. Comparability of research also needs an accepted and easily accessible reference. From experience, it is almost impossible to manufacture exact copies of test specimens at different locations. Round Robin tests are therefore needed to evaluate the performance of a test. Data evaluation is generally done using dedicated software, sometimes Hardware dependant and not interchangeable between systems. Software is ever more increasingly becoming more powerful and sophisticated. An in-depth evaluation needs to address the comparability and validation of Software used for data analysis and evaluation. The vision of a unified software pool for NDE investigations would undoubtedly support research tremendously. Quantitative NDE is mostly recommended to assess the condition of a structure. However, qualitative data can be very useful, especially for processes which change the material properties or deteriorate the structure (e.g. corrosion of reinforcement). The need for reliable baseline data is a key factor for such monitoring tasks. KW - Nuclear structures KW - Non-destructive testing KW - State of the art KW - Research needs PY - 2013 SP - 1 EP - 120 PB - BAM CY - Berlin AN - OPUS4-51049 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Quality Control of Hydrophobic Coatings with an Integrated Marker Element by laser Induced Breakdown Spectroscopy (LIBS) T2 - 2nd International Conference on Microstructural-related Durability of Cementitious Composites CY - Amsterdam, Netherlands DA - 2012-04-11 PY - 2012 AN - OPUS4-27412 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd A1 - Schalk, H. A1 - Bienert, K. A1 - Molkenthin, A. A1 - Goldschmidt, Sebastian A1 - Niederleithinger, Ernst T1 - Quality control of hydrophobic coatings with an integrated marker element by laser-induced breakdown spectroscopy (LIBS) N2 - Reinforced concrete structures are affected by damage, caused e.g., by freeze-thaw effects or corrosion. Most damage processes are triggered by moisture transport including soluble substances. Hydrophobic coatings can be used for prevention of such damage, but quantitative on-site quality assurance methods are so far missing. A way to overcome this problem is to integrate marker substances into the coating, which can be detected by spectroscopic methods. Different types of marker elements have been tested. It can be shown that transition metals are best suited for the task. Currently a LIBS (Laser Induces Breakdown Spectroscopy) system is developed for the measurement of penetration depth and content of the hydrophobic coating via the marker element in the peripheral zone of concrete. T2 - 2nd International conference Micro Durability - Microstructural-related durability of cementitious composites CY - Amsterdam, The Netherlands DA - 11.04.2012 KW - Hydrophobierung KW - Laser Induced Breakdown Spektroskopie (LIBS) KW - Qualitätskontrolle PY - 2012 SN - 978-2-35158-129-2 N1 - Serientitel: RILEM proceedings – Series title: RILEM proceedings VL - PRO83 SP - 1 EP - 10 AN - OPUS4-27534 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd A1 - Schaurich, Dieter ED - Forde, M.C. T1 - Laser induced breakdown spectroscopy for fast analysis of ingress profiles of ions on concrete N2 - An increasing number ofreinforced concrete structures, mainly in transportation infrastructure, sujfer from deterioration, e.g.freeze-thaw effects or corrosion. Deicing salts, which have been intensively used in the last decades, cause pitting corrosion on reinforcement due to penetration of Chloride ions. The penetration ofalkaline ions may also influence the alkali silica reaction (ASR) ofhighway structures. A comparatively new method for the application at building materials, laser-induced breakdown spectroscopy (L1BS), was used to determine element distributions and ingress profiles ofions on concrete specimens. With this method it is possible to measure directly on an optical accessible surface ofa specimen. The time neededfor sample preparation and measurement is low. With LIBS repeatable automated measurements on a large number of specimens can be carried out. The presented results show that the heterogeneity ofthe material is taken into Account and thus the errors due to the sampling is minimized. A mobile setup for on-site element analysis is presented. The paper describes the results measured on concrete samples obtainedfrom parking decks and cores taken from highways. A comparison with Standard Chemical analysis will be presented. T2 - Structural faults & repair 2012 - 14th International conference and exhibition CY - Edinburgh, Scotland DA - 03.07.2012 KW - Laser Induced Breakdown Spectroscopy (LIBS) KW - Chloride KW - Sulphate KW - Alkali metals KW - Damage KW - Non-destructive testing KW - Concrete KW - On-site PY - 2012 SN - 0-947664-71-7 SP - 1 EP - 8 PB - Engineering Technics Press AN - OPUS4-27535 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd A1 - Schaurich, Dieter A1 - Wiggenhauser, Herbert ED - Leeman, C.M. T1 - Laser-induced breakdown spectroscopy for fast analysis of ingress profiles of ions on concrete N2 - An increasing number of reinforced concrete structures, often components of transportation infrastructure, suffer from deterioration, e. g. freeze-thaw effects or corrosion. De-icing salts, which have beenintensively used in the last decades, may cause pitting corrosion at the reinforcement following the Penetration of chloride ions. The penetration of alkaline ions may also influence the alkali silica reaction (ASR) of highway structures. For the application at building materials a relatively new method, the laser induced breakdown spectroscopy (LIBS), was used to determine element distributions and ingress profiles of ions on concretespecimens. LIBS is a testing method which complements the Standard Chemical methods. It is able to measure directly on an optical accessible surface of a specimen. The time needed for sample preparation and measurement is low. The described setup allows repeatable automated measurements at a high number of specimens. The results presented here, show how the heterogeneity of the material can be qualified and how the errors caused by the sampling procedure can be minimised. A mobile setup is available for on site element analysis. Following the results taken at laboratory samples, concrete samples obtained from parking decks and cores taken at highways are presented. The distribution of the characteristic ions and/or the Ingress characteristic of damaging substances are determined. T2 - NDE/NDT for highways and bridges - Structural materials technology -SMT- CY - New York City, NY, USA DA - 21.08.2012 KW - Beton KW - Laser Induced Breakdown Spektroskopie PY - 2012 SN - 978-1-57117-235-8 SP - 384 EP - 391 AN - OPUS4-27528 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ebell, Gino A1 - Burkert, Andreas A1 - Günther, Tobias A1 - Wilsch, Gerd T1 - Untersuchungen zum korrosionsauslösenden Chloridgehalt an nicht rostendem ferritischem Betonstahl in Mörtel N2 - Der maßgebliche Korrosionsschutz von nicht rostendem Stahl in Beton basiert, anders als bei unlegiertem Betonstahl, auf der Ausbildung einer Chromoxidschicht. Die Chromoxidschicht ist in alkalischem und in carbonatisiertem Beton beständig, sodass nicht rostende Stähle in einem passiven Zustand vorliegen. Die Initiierung von Lochkorrosionserscheinungen ist dagegen auch an nicht rostenden Stählen in Beton möglich. Der korrosionsauslösende Chloridgehalt ist neben dem Gehalt an Legierungselementen (insbesondere dem Chromgehalt) und der Oberflächenbeschaffenheit auch vom Konzentrationsverhältnis von OH“ zu CI“ im Elektrolyten abhängig. Daher ist prinzipiell zu erwarten, dass in karbonatisierten Betonen geringere Chloridgehalte Korrosion initiieren können als in Betonen mit höheren pH-Werten. Dies gilt in besonderem Maße für nicht rostende Betonstähle mit geringen Chromgehalten, wie z. B. Produkte aus dem Werkstoff 1.4003 (X2CrNi12) mit seiner im Vergleich zu den Standardausteniten geringen Beständigkeit. Um den kritischen korrosionsauslösenden Chloridgehalt am Beispiel eines am Markt verfügbaren ferritischen Chromstahls zu bestimmen, wurden an der Bundesanstalt für Materialforschung und -prüfung (BAM) umfangreiche Untersuchungen zu beschleunigten Korrosionsversuchen in alkalischen und karbonatisierten Mörteln durchgeführt. Mittels Laser-induced Breakdown Spectroscopy (LIBS) konnten die korrosionsauslösenden Chloridgehalte im Phasengrenzbereich Betonstahl-Mörtel ermittelt werden. KW - Korrosion KW - Betonstahl KW - Nicht rostender KW - LIBS KW - Chloridgehalt KW - Kritischer PY - 2020 DO - https://doi.org/10.1002/bate.201900077 SN - 0932-8351 VL - 97 IS - 1 SP - 21 EP - 31 PB - Ernst & Sohn CY - Berlin AN - OPUS4-50247 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schwarz, W. A1 - Wilsch, Gerd A1 - Katsumi, N. A1 - Ebell, Gino A1 - Völker, Tobias T1 - Ion distribution in concrete overlay, mapped by laser induced breakdown spectroscopy (LIBS), modified by an embedded zinc anode N2 - Galvanic corrosion protection by embedded zinc anodes is an accepted technique for the corrosion protection of reinforcing steel in concrete. Galvanic currents flow between the zinc anode and the steel reinforcement due to the potential difference that is in the range of a few hundred mV. The ion distribution was studied on two steel reinforced concrete specimens admixed with 3 wt.% chloride/wt. cement and galvanically protected by a surface applied EZ-anode. On both specimens, a zinc anode was embedded and glued to the concrete surface by a geo-polymer-based chloride-free binder. At one specimen, the EZ-anode was operated for 2,5 years, the EZ-anode at the other specimen was not electrically connected to the reinforcement, this specimen serves as a reference. Both specimens have been stored under identical conditions. The ion distribution between the anode (EZ-ANODE) and cathode (steel reinforcement) was studied by laser-induced breakdown spectroscopy (LIBS) after 7 months, 12 months, and 2,5 years. Results of the LIBS studies on the specimen with activated EZ-anode after 7 months, 12 months, and 2,5 years and of the reference specimen after 2,5 years are reported. Results show that diffusion of ions contributes to the changes in the ion distribution but migration, especially of chlorides towards the EZ-anode is significant despite the weak electric field – several hundred millivolts - generated by the galvanic current. Results show that chloride ions accumulate near the zinc-anode as in water-insoluble zinc-hydroxy chlorides - Simonkollite. T2 - ICCRRR 2022 CY - Capetown, South Africa KW - Corrosion KW - LIBS KW - Zinc KW - Anode PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-560576 DO - https://doi.org/10.1051/matecconf/202236404023 SN - 2261-236X VL - 364 SP - 1 EP - 7 PB - EDP Sciences CY - Les Ulis AN - OPUS4-56057 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dalichow, Dirk A1 - Blaschke, Jil A1 - Wilsch, Gerd A1 - Völker, Tobias T1 - Revolutionizing Concrete Analysis and Maintenance with Laser-Induced Breakdown Spectroscopy N2 - Laser-induced breakdown spectroscopy (LIBS) is a valuable complement to established methods for the chemical analysis of concrete. Compared to conventional techniques, LIBS enables spatially resolved imaging of harmful ion distributions within the cementitious matrix. It allows the simultaneous detection of all relevant ions and degradation mechanisms, facilitating a better understanding of interacting processes. The benefits of multi-element analysis are illustrated through selected examples that highlight the method’s superior information content. Ion penetration profiles are recorded at a resolution of 0.25 mm, providing high-quality input data for service life modelling. Instead of drill dust, a 50 mm core sample is used. The measurement is automated, requires no chemical reagents or elaborate sample preparation, and is completed within minutes. KW - LIBS KW - Durability KW - Ion transport profiling KW - Concrete analysis KW - Service life assessment PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-642846 DO - https://doi.org/10.58286/31656 SN - 1435-4934 VL - 30 IS - 10 SP - 1 EP - 8 PB - NDT.net GmbH & Co. KG AN - OPUS4-64284 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Torge, Manfred A1 - Feldmann, Ines A1 - Günther, Tobias A1 - Wilsch, Gerd ED - Glaser, L. T1 - Analytische Untersuchungen an Glasmalfarben mittels EDX und LIBS N2 - Nach 1850 wurde zur weiteren Herabsetzung der Einbrenntemperatur von Glasmalfarben Borax (Na2B4O7 · 10 H2O) zugesetzt. Das Verhältnis war nun 1 Teil SiO2, 3 Teile PbO und 0,5 Teile Borax. Der analytische Nachweis von Bor in eingebrannten Malschichten war bisher jedoch nicht möglich.Daher wurden in Laborversuchen Glasmalfarben mit unterschiedlichem Gehalt an Borax auf Modellgläser aufgetragen, eingebrannt und anschließend unter simulierten Umweltbedingungen zeitraffend im Klimaschrank bewittert. Mit Hilfe von elektronenmikroskopischen Untersuchungen können Malschichten charakterisiert werden und somit Hinweise auf mögliche Schadensursachen liefern. Erste Versuche zum Nachweis von Bor erfolgten mit Hilfe von LIBS-Messungen (Laser Induced Breakdown Spectroscopy) an im Labor hergestellten Glasmalfarben mit unterschiedlichem Boraxgehalt. T2 - Archäometrie und Denkmalpflege 2018 CY - Hamburg, Germany DA - 20.03.2018 KW - Glasmalfarben KW - Umweltsimulation KW - Analytik PY - 2018 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-450664 SN - 978-3-945931-16-5 DO - https://doi.org/10.3204/DESY-PROC-2018-01 SN - 1435-8077 SP - 283 EP - 285 PB - Deutsches Elektronen -Synchrotron CY - Hamburg AN - OPUS4-45066 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gottlieb, Cassian A1 - Gojani, Ardian A1 - Völker, Tobias A1 - Günther, Tobias A1 - Gornushkin, Igor B. A1 - Wilsch, Gerd A1 - Günster, Jens T1 - Investigation of grain sizes in cement-based materials and their influence on laser-induced plasmas by shadowgraphy and plasma imaging N2 - The effect of particle grain sizes in different cement-based mixtures on the laser-induced plasma evolution is studied using two experimental methods: (i) temporal and spatial evolution of the laser-induced shock wave is investigated using shadowgraphy and two-dimensional plasma imaging, and (ii) temporal and spatial distribution of elements in the plasma is investigated using two-dimensional spectral imaging. This study is motivated by the interest in applying laser-induced breakdown spectroscopy (LIBS) for chemical analysis of concrete, and subsequently obtain information related to damage assessment of structures like bridges and parking decks. The distribution of grain sizes is of major interest in civil engineering as for making concrete different aggregate grain sizes defined by a sieving curve (64mm to 0.125 mm) are needed. Aggregates up to a size of 180 μm can be excluded from the data set, therefore only the amount of small aggregates with a grain size below 180 μm must be considered with LIBS. All components of the concrete with a grain size smaller than 0.125mm are related to the flour grain content. Tested samples consisted of dry and hardened cement paste (water-cement ratio w/z=0.5), which served as a reference. Aggregate mixtures were made by adding flour grains (size 40 μm) and silica fume (size 0.1 μm) in different ratios to cement: 10%, 30%, 50% and 60%, all combined to the remaining percentage of dry or hydrated cement. The visualization results show that a dependance in the evolution of the plasma as a function of sample grain size can be detected only in the initial stages of the plasma formation, that is, at the initial 3 μs of the plasma life. Spectral information reveals the elemental distribution of the silicon and calcium in plasma, in both neutral and ionized form. Here also, a significant effect is observed in the first 1 μs of the plasma lifetime. KW - LIBS KW - Cement-based materials KW - Particle size KW - Shadowgraphy KW - Plasma imaging PY - 2020 DO - https://doi.org/10.1016/j.sab.2020.105772 VL - 165 SP - 105772 PB - Elsevier B.V. AN - OPUS4-50319 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Völker, Tobias A1 - Blaschke, Jil A1 - Lierenfeld, Matthias A1 - Wilsch, Gerd A1 - Dalichow, Dirk A1 - Truffer, Philipp A1 - Kruschwitz, Sabine T1 - Aktuelle Anwendungsbeispiele der laserinduzierten Plasmaspektroskopie in der Bauwerksdiagnostik N2 - Die Zustandsbewertung und Instandhaltung von Betonbauwerken erfordert zuverlässige und effiziente Analysemethoden, um komplexe Schadensmechanismen frühzeitig erkennen und fundiert bewerten zu können. Klassische chemisch-analytische Verfahren in der Betonanalytik liefern zwar präzise Ergebnisse bezogen auf die Probenmasse, sind jedoch mit erheblichem Laboraufwand verbunden, in ihrer räumlichen Auflösung durch die Probenahme begrenzt und hinsichtlich der Ergebnisinterpretation mit Unsicherheiten behaftet. Die laserinduzierte Plasmaspektroskopie (LIBS) bietet hier ein hohes Potenzial als schnelle, bildgebende und weitgehend zerstörungsarme Alternative. In den vergangenen Jahren hat sich das Verfahren zunehmend in der Bauwerksdiagnostik etabliert und wird heute für ein breites Spektrum an Anwendungen eingesetzt. Der vorliegende Beitrag gibt einen Überblick über den aktuellen Stand der LIBS-Anwendungen und zeigt anhand ausgewählter Praxisbeispiele die Leistungsfähigkeit, den Mehrwert, die Grenzen und die zukünftigen Entwicklungsperspektiven des Verfahrens auf. KW - LIBS KW - Spektroskopie KW - Chemische Analyse KW - Infrastruktur KW - Bauwerksdiagnostik PY - 2026 DO - https://doi.org/10.1002/best.70078 SN - 1437-1006 SP - 1 EP - 13 AN - OPUS4-65445 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gottlieb, C. A1 - Lierenfeld, M. B. A1 - Wilsch, Gerd A1 - Bohling, C. T1 - Es geht auch einfacher N2 - Mit laserbasiertem Verfahren Zustand von Betonbauwerken erfassen: Die Laserinduzierte Breakdown Spektroskopie (LIBS) stellt eine Alternative zur nasschemischen Analyse dar, um den Zustand von Betonbauwerken zu erfassen. Bei diesem Verfahren laufen der Analysevorgang und die Auswertung automatisiert ab. Ein Prototyp für die mobile Anwendung auf der Baustelle steht zur Verfügung. So kann auf Knopfdruck ein schriftlicher Bericht erstellt werden, der einen genauen Wert für die Eindringtiefe eines relevanten Elements wie Chlorid ausgibt. KW - Beton KW - LIBS KW - Chlorid KW - Vor-Ort-Untersuchung PY - 2019 VL - 42 IS - 7 SP - 28 EP - 31 PB - Verlagsgesellschaft Rudolf Müller GmbH CY - Köln AN - OPUS4-50283 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Schwarz, W. A1 - Wilsch, Gerd A1 - Pichelhöfer, A. A1 - Ebell, Gino A1 - Völker, Tobias T1 - Galvanic chloride extraction by an embedded zinc anode: Ion distribution mapped by laser induced breakdown spectroscopy (LIBS) N2 - An important aspect with regard to the service life of zinc based galvanic anodes and the durability of the corrosion protection of steel in concrete is the “galvanic chloride extraction”. Chloride ions move in the electric field generated by the current, flowing between the galvanic anode and the cathodic steel. Migration leads to an accumulation of anions, e.g. chloride ions, at the anode and depletion of chlorides near the steel rebar surface. The ion migration was studied on steel reinforced concrete specimens admixed with 3 wt.% chloride/wt. cement and galvanically protected by a surface applied embedded zinc anode (EZA). The zinc anode was embedded and glued to the concrete surface by a geo-polymer based chloride free binder. The EZA was operated over a period of 1 year and the ion distribution between anode (EZA) and cathode (steel reinforcement) was studied by laser induced breakdown spectroscopy (LIBS) after 5 months, 7 months and 12 months. The results show that chloride ions efficiently migrate in the direction of the zinc-anode and accumulate there. Chloride distribution in the EZA correlates with the distribution of zinc ions generated by the anodic dissolution of the zinc anode in the binder matrix. The microstructure of the binder matrix and its interface to the zinc-anode are studied by REM/EDX – preliminary results will be reported. T2 - Concrete Solutions 2019 CY - Cluj Napoca, Romania DA - 30.09.2019 KW - Galvanic corrosion KW - Corrosion KW - Chloride extraction PY - 2019 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-488189 DO - https://doi.org/10.1051/matecconf/201928903010 VL - 289 SP - 03010, 1 EP - 5 PB - MATEC Web of Conferences AN - OPUS4-48818 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd A1 - Günther, Tobias A1 - Völker, Tobias T1 - LIBS – Betonanalytik mit dem Laser N2 - Es wird ein alternatives Verfahren zur schnellen zweidimensionalen Analyse der chemischen Zusammensetzung von Baustoffen vorgestellt. Dieses beruht auf der Kombination des Abtrags einer geringen Materialmenge durch einen gepulsten Laser, der Plasmaerzeugung und der Analyse der Lichtemission des Plasmas mittels optischer Spektroskopie. Es können prinzipiell alle Elemente gleichzeitig nachgewiesen werden. Damit ist es möglich einerseits Informationen über den Baustoff an sich als auch über den Eintrag potentiell schädigender Elemente (z. B. Cl, C, Na, K, S) zu gewinnen. Das Verfahren kann automatisiert im Labor oder als mobile Version direkt vor Ort eingesetzt werden. Es liefert zweidimensionale Bilder der Elementverteilung in Echtzeit. Es kann ohne große Probenvorbereitung z. B. direkt an der Querschnittsfläche eines Bohrkernes gemessen werden. Die Messung dauert nur wenige Minuten. Das Prinzip der Messung, die Vor- und die Nachteile, sowie die verfügbare Gerätetechnik für den Einsatz im Labor oder direkt am Bauwerk werden vorgestellt. Abschließend werden praktische Beispiele für die Anwendung des LIBS-Verfahrens zur Erfassung des Chlorid-Eintrages, der Karbonatisierung und der Verteilung von Schwefel präsentiert. T2 - 9. Betonfachtagung CY - Berlin, Germany DA - 12.11.2019 KW - Chloride KW - Beton KW - LIBS KW - Schädigung PY - 2019 SP - 1 PB - InformationsZentrum Beton GmbH CY - Berlin AN - OPUS4-51675 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Fast quantitave chemical analysis of concrete using LIBS N2 - Overview of application of LIBS for the fast and automated quantitative chemical analysis of concrete. T2 - NDT-E Workshop CY - Berlin, Germany DA - 12.06.2019 KW - Sulphate KW - LIBS KW - Concrete KW - Damage KW - Chloride KW - Mapping PY - 2019 AN - OPUS4-51704 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - LIBS – Betonanalytik mir dem Laser N2 - Es wird ein alternatives Verfahren zur schnellen zweidimensionalen Analyse der chemischen Zusammensetzung von Baustoffen vorgestellt. Dieses beruht auf der Kombination des Abtrags einer geringen Materialmenge durch einen gepulsten Laser, der Plasmaerzeugung und der Analyse der Lichtemission des Plasmas mittels optischer Spektroskopie. Es können prinzipiell alle Elemente gleichzeitig nachgewiesen werden. Damit ist es möglich einerseits Informationen über den Baustoff an sich als auch über den Eintrag potentiell schädigender Elemente (z. B. Cl, C, Na, K, S) zu gewinnen. Das Verfahren kann automatisiert im Labor oder als mobile Version direkt vor Ort eingesetzt werden. Es liefert zweidimensionale Bilder der Elementverteilung in Echtzeit. Es kann ohne große Probenvorbereitung z. B. direkt an der Querschnittsfläche eines Bohrkernes gemessen werden. Die Messung dauert nur wenige Minuten. Das Prinzip der Messung, die Vor- und die Nachteile, sowie die verfügbare Gerätetechnik für den Einsatz im Labor oder direkt am Bauwerk werden vorgestellt. Abschließend werden praktische Beispiele für die Anwendung des LIBS-Verfahrens zur Erfassung des Chlorid-Eintrages, der Karbonatisierung und der Verteilung von Schwefel präsentiert. T2 - 9. Betonfachtagung CY - Berlin, Germany DA - 12.11.2019 KW - Chloride KW - Beton KW - LIBS KW - Schädigung PY - 2019 AN - OPUS4-51673 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Laser-Induced Breakdown Spectroscopy (LIBS) Automated 2D chemical analysis of chloride content in concrete structures N2 - The application of a LIBS system is presented. A diode-pumped low energy laser (3 mJ, 1.5 ns, 100 Hz) and a compact NIR spectrometer are used. A scanner allows the two-dimensional element mapping. For the quantitative analysis calibration of the system is carried out with reference samples in a concentration range of chlorine of 0.05 wt.% to 2.5 wt.%. To determine the 2D distribution of harmful elements (Cl, C), concrete cores were drilled, split and analyzed directly. By comparing the chloride ingress and the carbonation, the interaction of both processes can be visualized in one measurement that takes less than 10 minutes with a drill core of 50 mm x 100 mm. Results obtained were compared and verified with standard measurements. T2 - Concrete Solutions 2019 CY - Cluj Napoca, Romania DA - 30.09.2019 KW - Chloride KW - Beton KW - LIBS KW - Schädigung PY - 2019 AN - OPUS4-51703 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Mobile LIBS-System for condition assesment of concrete structures on-site N2 - Application of a mobile LIBS system for on-site investigation of chemical composition of concrete. T2 - SMAR 2019 CY - Potsdam, Germany DA - 27.08.2019 KW - Mobile system KW - LIBS KW - Concrete KW - Damage KW - Chloride KW - Sulphate KW - Mapping PY - 2019 AN - OPUS4-51706 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Millar, Steven A1 - Kruschwitz, Sabine A1 - Wilsch, Gerd T1 - Determination of total chloride content in cement pastes with laser-induced breakdown spectroscopy (LIBS) N2 - The presented work discusses the accuracy of Laser Induced Breakdown Spectroscopy (LIBS) in determining the total chloride content in cement pastes. LIBS as an emission spectroscopy method is used to detect simultaneously several elements present in cement-based materials. By scanning surfaces the variability in the spatial distribution of elements can be visualised. However, for a quantification of the results, studies are necessary to characterise possible influences due to the wide variation of the chemical compositions in which cement can occur. It is shown how the calibration can be done, how the calibration samples were produced, and which statistical parameters are necessary to describe the precision of the regression. The performance of LIBS is estimated by detecting chloride in validation samples. Therefore, 55 samples and 7 ets with changing mix ompositions were produced. The presented study deals with possible influences of different mix compositions, ncluding different cations of chloride, varying w/c-ratios and the artial replacement of Portland cement with last furnace slag (50% BFS) and limestone (30% LS). Comparing the LIBS results with otentiometric titration, n accuracy of±0.05 wt%/total has been determined. KW - Spectroscopy KW - LIBS KW - Chloride KW - Quantification KW - Cement PY - 2019 DO - https://doi.org/10.1016/j.cemconres.2018.12.001 SN - 0008-8846 VL - 117 IS - March SP - 16 EP - 22 PB - Elsevier CY - Amsterdam AN - OPUS4-47059 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - LIBS for the analysis of concrete N2 - Special features and examples of using LIBS on concrete. T2 - Workshop on tandem LIBS/LA-ICP-MS CY - Berlin, Germany DA - 18.11.2019 KW - Mobile system KW - LIBS KW - Concrete KW - Damage KW - Chloride KW - Sulphate KW - Mapping PY - 2019 AN - OPUS4-51710 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd T1 - Mobile LIBS system for evaluation of concrete structures on site N2 - Features and application of a mobile LIBS system for evaluation of concrete structures on-site. T2 - EMSLIBS 2019 CY - Brno, Czech Republic DA - 08.09.2019 KW - On-site KW - LIBS KW - Concrete KW - Mapping KW - Evaluation PY - 2019 AN - OPUS4-51711 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Millar, Steven A1 - Gottlieb, Cassian A1 - Wilsch, Gerd A1 - Eichler, Thorsten A1 - Bohling, C. A1 - Molkenthin, A. T1 - Laser induced breakdown spectroscopy (LIBS) - On-site investigatioons on a bridge with a mobile LIBS-system N2 - LIBS is on the step from a laboratory application to on-site analysis. A validated mobile LIBS-system for on-site application on building materials is under development at BAM in cooperation with industrial partners (system developers and companies), who will use this technique for investigation on building structures like bridges and parking decks. The system is designed to measure the content of harmful species like chlorine, sulfur or alkalis, to give the engineer a tool for the estimation of the condition of concrete structures and for quality assurance during concrete repair work on-site. In these work results of on-site measurements on a chloride contaminated bridge are shown. Further work will focus on providing guidelines to establish LIBS as a standard procedure for chemical investigations of building materials. T2 - NDT-CE 2015 - International symposium non-destructive testing in civil engineering CY - Berlin, Germany DA - 15.09.2015 KW - LIBS KW - Chlorides KW - Sulfur KW - Alkalis KW - Corrosion KW - ASR KW - Chemical analysis KW - Chloride KW - Elementanalyse KW - Natrium KW - Baustoffuntersuchungen KW - Baustoffe KW - Dauerhaftigkeit KW - Messsysteme KW - Mobiles LIBS PY - 2015 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-345795 UR - http://www.ndt.net/?id=18296 SN - 1435-4934 VL - 20 IS - 11 SP - 1 EP - 5 PB - NDT.net CY - Kirchwald AN - OPUS4-34579 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -