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 -