TY - CONF A1 - Eichler, Thorsten A1 - Burkert, Andreas A1 - Beck, Matthias T1 - Elektrochemische Rauschmessungen an Stahl in zementös gebundenen Baustoffen T2 - GfKORR-Workshop "Korrosionsdiagnostik und Korrosionsüberwachung mit Hilfe des elektrochemischen Rauschens" CY - Magdeburg, Germany DA - 2005-09-21 PY - 2005 AN - OPUS4-11092 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Burkert, Andreas T1 - Elektrochemische Impedanzspektroskopie zur Analyse von Korrosionssystemen T2 - C3 Prozess- und Analysentechnik GmbH, Seminar "Moderne elektrochemische Prüfverfahren", BAM CY - Berlin, Germany DA - 2005-09-15 PY - 2005 AN - OPUS4-10529 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Helm, C. A1 - Eichler, Thorsten A1 - Raupach, M. A1 - Isecke, Bernd T1 - Time dependency of current and potential distribution during the cathodic protection of RC structures N2 - Cathodic protection (CP) is a common method for rehabilitation of reinforced concrete structures suffering from Chloride induced corrosion. A sufficient protection of the corroding rebar can be ensured by use of several protection criteria. The use of these assessment criteria, in particular the so called 100 mV-criterion, can lead to erroneous resuits for certain unconventional arrangements of rebar and cp anode. Therefore a joint research project of the Institute for Building Materials Research, RWTH-Aachen University, Germany, (ibac) and the Federal Institute for Materials Research and Testing, Berlin, Germany, (BAM) has been set up to determine the applicability of CP under arbitrary geometrical conditions. A special focus was set on the applicability of surface applied anode Systems for protection of the reinforcement of structures opposite to the accessible side (e.g. outer side of tunnel Shell, Bridge deck protected from inside a box girder) In this paper, the impact of the time dependent changes of the Polarisation behaviour of the rebar on the current and potential distribution is shown by means of parametric studies using the FEM method. T2 - EUROCORR 2011 - Developing solutions for the global challenge CY - Stockholm, Sweden DA - 04.09.2011 KW - Cathodic protection KW - Long time effects of cathodic polarisation KW - FEM-modelling KW - Steel in concrete PY - 2011 SP - 1 EP - 11 AN - OPUS4-25326 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Eichler, Thorsten T1 - Zu den sekundären Schutzmechanismen beim kathodischen Korrosionsschutz von Stahl in alkalischen Medien N2 - Die vorliegende Arbeit behandelt die Auswirkungen der sekundären Schutzmechanismen beim kathodischen Korrosionsschutz von Stahl in alkalischen Medien. Auf der Grundlage von Untersuchungen in künstlichen Betonporenlösungen wird ein Modell zur Wirkungsweise der sekundären Schutzmechanismen entwickelt. Die Ergebnisse belegen die wesentliche Bedeutung des Verhältnisses zwischen Chlorid- und Hydroxidionenkonzentration im Elektrolyten bezüglich der im System verbleibenden Korrosionsrate nach Abschalten des Schutzstroms sowie hinsichtlich der kathodischen Polarisierbarkeit des Schutzobjektes. Es konnte gezeigt werden, dass die Verringerung des Verhältnisses zwischen Chlorid- und Hydroxidionenkonzentration auf einen spezifischen Grenzwert zur nachhaltigen Verringerung der Korrosionsrate, um einen Faktor zwischen 10 und 1000, führend kann. Weiterhin belegen die Ergebnisse, dass durch den kathodischen Korrosionsschutz nur in Ausnahmefällen die Repassivierung des Schutzobjektes zu beobachten ist. Der zweite Teil der Untersuchungen befasst sich mit den messbaren Auswirkungen kathodischer Langzeitpolarisation auf das Korrosionsverhalten von Stahl in chloridhaltigen Mörtelprobekörpern. Hier konnte und praxisnahen Betriebsbedingungen gezeigt werden, dass signifikante Migrationseffekte auch bei verhältnismäßig geringer Feldstärke auftreten können. Weiterhin konnte die kathodische Polarisationskinetik als Funktion der während der Polarisation geflossenen Ladungsmenge dargestellt werden.---------------------------------------------------------------------------------------------------------------------------- The present work discusses the impact of the secondary protection mechanisms during cathodic protection of steel in alkaline media. On the basis of investigations in artificial concrete pore solutions a model was developed concerning the effectiveness of the secondary protection mechanisms. The results support the essential significance of the ratio between chloride and hydroxide ion in the electrolyte concerning the in the system remaining corrosion rate after switching off the protection current as well as regarding the polarisability of the object to be protected. It could be shown, that reducing the ratio between chloride and hydroxide ion concentration to a specific value results in a sustaining reduction of the remaining corrosion rate, of a factor between 10 and 1000. Further on the results prove that repassivation by cathodic protection was only observable in exceptional cases. The second part of the investigations deals with the measurable effects of cathodic long term polarisation on the corrosion behaviour of steel in chloride containing mortar specimens. It was possible to show under nearly practical conditions, that significant migration effects can occur even at comparably low field strengths. Further on the cathodic polarisation kinetics could be presented as function of the charge flown during polarisation. KW - Kathodischer Korrosionsschutz KW - Instandsetzung KW - Instandhaltung KW - Chlorinduzierte Korrosion KW - Stahlbeton KW - Elektrochemische Instandsetzungsverfahren KW - Lochkorrosion KW - Chlorid KW - Beton PY - 2012 SP - 1 EP - 169 CY - Aachen AN - OPUS4-27444 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Isecke, Bernd T1 - Kathodischer Korrosionsschutz von Stahl im Beton - Möglichkeiten und Grenzen mit praktischen Beispielen T2 - 23. Baupraktisches Informationsseminar für Auftraggeber, Planer und Ausführende von Instandsetzungsmaßnahmen CY - Bad Nauheim, Germany DA - 2012-11-07 KW - Kathodischer Korrosionsschutz KW - Instandsetzung KW - Instandhaltung KW - Chloridinduzierte Korrosion KW - Stahlbeton PY - 2012 SP - 15 EP - 19 AN - OPUS4-27453 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Isecke, Bernd ED - Gieler-Breßmer, S. T1 - Die DIN EN 15257 und ihre Bedeutung für Bauherren, Planer und Ausführende T2 - 10. Symposium Kathodischer Korrosionsschutz von Stahlbetonbauwerken CY - Esslingen, Germany DA - 2012-11-22 KW - Kathodischer Korrosionsschutz KW - Instandsetzung KW - Chloridinduzierte Korrosion KW - Stahlbeton KW - Normung KW - Regelwerke KW - Zertifizierung KW - Ausbildung PY - 2012 SN - 978-3-943563-02-3 SP - 5 EP - 9 AN - OPUS4-27456 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Isecke, Bernd A1 - Wilsch, Gerd T1 - Investigations on the secondary protection mechanisms in cathodic protection applications T2 - Structural Faults and Repair CY - Edinburgh, Scotland DA - 2012-07-02 PY - 2012 AN - OPUS4-26246 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Burkert, Andreas T1 - Investigations on mild steel in high alkaline environment by electrochemical noise T2 - CORROSION 2007 CY - Nashville, TN, USA DA - 2007-03-11 PY - 2007 AN - OPUS4-14988 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Isecke, Bernd A1 - Burkert, Andreas T1 - Electrochemical noise measurements for monitoring the repassivation of mild steel after cathodic polarization KW - Electrochemical Noise KW - Electrochemical Impedance Spectroscopy KW - Cathodic Protection KW - Steel in Concrete KW - Repassivation KW - Corrosion Monitoring PY - 2007 SN - 978-80-903933-0-1 SP - 1 EP - 7 PB - SVUOM CY - Prag AN - OPUS4-15895 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Isecke, Bernd T1 - Investigations on alterations of electrochemical parameters of steel in chloride containing concrete in consequence of cathodic polarization T2 - EUROCORR 2008 CY - Edinburgh, Scotland DA - 2008-09-07 PY - 2008 AN - OPUS4-17915 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Isecke, Bernd A1 - Burkert, Andreas T1 - Investigations on changes at the steel-concrete interface due to cathodic polarization T2 - EIS 2007 CY - Argelés-Sur-Mer, France DA - 2007-06-03 PY - 2007 AN - OPUS4-14869 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 - CONF A1 - Eichler, Thorsten A1 - Isecke, Bernd A1 - Burkert, Andreas T1 - Electrochemicals noise measurements for monitoring the repassivation of mild steel after cathodic polarization T2 - Corrosion and Material Protection 2007 CY - Prague, Czech Republic DA - 2007-10-01 PY - 2007 AN - OPUS4-16221 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Isecke, Bernd A1 - Burkert, Andreas T1 - Investigations on the repassivation of carbon steel in consequence of cathodic polarization T2 - Eurocorr 2007 CY - Freiburg, Germany DA - 2007-09-09 PY - 2007 AN - OPUS4-16222 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Isecke, Bernd T1 - Grundlagen des kathodischen Korrosionsschutzes von Stahl in Beton T2 - KKS-Symposium CY - Esslingen am Neckar, Germany DA - 2007-11-09 PY - 2007 AN - OPUS4-16223 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Isecke, Bernd T1 - Untersuchungen zum Einfluss der kathodischen Polarisation auf das Korrosionsverhalten von Stahl in chloridhaltigem Beton T2 - Bunsenkolloquium "65 Jahre Potentiostat", Fraunhofer IKTS CY - Dresden, Germany DA - 2007-11-08 PY - 2007 AN - OPUS4-16224 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Isecke, Bernd T1 - Untersuchungen zum Einfluss kathodischer Polarisation auf das Repassivierungsverhalten von Stahl in Beton T2 - Dechema-Seminar: Elektrochemische Messmethoden und ihre Anwendungen in zukunftsweisenden Forschungsbereichen CY - Frankfurt am Main, Germany DA - 2007-09-19 PY - 2007 AN - OPUS4-16225 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Burkert, Andreas T1 - Investigations on black steel in high alkaline environment by means of electrochemical noise T2 - CORROSION 2007 CY - Nashville, TN, USA DA - 2007-03-11 KW - Electrochemical noise KW - Unalloyed steel KW - Concrete KW - High alkaline environment KW - Pitting corrosion KW - Steel in Concrete KW - Chlorides KW - Cement KW - Mortar KW - Black steel PY - 2007 SP - 1(?) EP - 15(?) PB - NACE International CY - Houston AN - OPUS4-14544 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Eichler, Thorsten A1 - Isecke, Bernd A1 - Klein, H.-H. A1 - Schade, A. A1 - Pruckner, F. A1 - Michel, S. T1 - Kathodischer Korrosionsschutz von Stahl in Beton - Instandsetzung des Parkhauses "Am Gericht" in Frankfurt am Main N2 - Die Instandsetzung von Stahlbetonbauteilen bzw.-werken, welche durch chloridinduzierte Korrosion der Bewehrung gefährdet oder bereits geschädigt sind, hat in den letzten Jahrzehnten weltweit an Bedeutung gewonnen. Der kathodische Korrosionsschutz, als elektrochemisches Instandsetzungsverfahren, bildet in diesem Fall eine zuverlässige und oftmals kostengünstige Methode zur Instandsetzung. Am Beispiel des Parkhauses Am Gericht in Frankfurt am Main werden die Durchführung solch einer Maßnahme sowie die Besonderheiten des Verfahrens beschrieben. Es werden die theoretischen Hintergründe erläutert und die praktische Umsetzung sowie zu klärende Detailfragen beschrieben. Die Daten der ersten Depolarisationsmessungen zeigen den aktuellen Zustand der Anlage sowie des Schutzobjektes. KW - Stahlbeton KW - Kathodischer Korrosionsschutz KW - Korrosion KW - Lochkorrosion KW - Instandsetzung KW - Elektrochemische Verfahren PY - 2007 SN - 0005-9900 SN - 1437-1006 VL - 102 IS - 5 SP - 310 EP - 320 PB - Ernst CY - Berlin AN - OPUS4-14769 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Isecke, Bernd A1 - Eichler, Thorsten A1 - Burkert, Andreas T1 - Investigations on the repassivation of carbon steel in consequence of cathodic polarization N2 - Pitting corrosion of carbon steel and iron in chloride containing alkaline environment is already well investigated, although a couple of questions are not clarified satisfactorily. The critical chloride content for steel in concrete and the critical chloride to hydroxide ion ratio for steel in alkaline solutions is still a major concern, considering chloride induced corrosion problems of steel in concrete. Another not satisfactorily clarified point is the repassivation of carbon steel in consequence of cathodic polarization. In the recent literature some indications are shown that repassivation occurs after a certain time of polarization. GLASS [4-9] and PEDEFERRI [1-3] draw the conclusion that the ennoblement of open circuit potentials (OCP) indicates re-passivation effects due to cathodic polarization. SAGÜÉS [10] carried out potentiodynamic repassivation tests and draws the conclusion that the repassivation potential Er is nearly independent of the solution composition, but influenced by severity of corrosion attack and is in the potential range from - 0.8 V to - 0.4 V vs. Saturated Calomel Electrode (SCE). The transferability of SAGÜÉS’ results to questions concerning cathodic protection (cp) is questionable, as potentiodynamic polarization tests (PPT) give no information on changes induced by long time polarization. Therefore, the investigations discussed in this paper aim to clarify, to what extend the re-passivation of carbon steel due to cathodic polarization occurs, and if the ennoblement of OCP is a sufficient indication for repassivation. In a first step the corrosion state of five nominal equal test specimens was determined by electrochemical techniques, i.e. electrochemical noise measurements (ENM) and electrochemical impedance spectroscopy (EIS). After determining the initial corrosion state by evaluating the charge transfer resistance and the polarization resistance respectively as well as evaluating potential and current noise signals, the specimens were polarized cathodically. Impedance data were recorded previous to, during and after polarization. The impedance data were evaluated by equivalent circuit fitting with special attention to charge transfer resistances and diffusion properties. The results show that reduction of oxides and oxygen diffusion during cathodic polarization has strong impact on the system’s behavior. T2 - EUROCORR 2007 CY - Freiburg im Breisgau, Germany DA - 2007-09-09 KW - Concrete KW - Carbon steel KW - Cathodic protection KW - Re-passivation KW - Pitting corrosion PY - 2007 N1 - Serientitel: EFC-Event – Series title: EFC-Event IS - 289 SP - 1 EP - 15 PB - DECHEMA CY - Frankfurt am Main AN - OPUS4-15822 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Eichler, Thorsten A1 - Burkert, Andreas A1 - Beck, Matthias T1 - Electrochemical noise measurements on unalloyed steel in chloride-containing alkaline environment N2 - The investigations discussed in this paper aim to clarify whether electrochemical noise measurements (ENM) are capable for application in concrete and mortar, particularly with regard to pitting initiation in such environment. For these purposes, the results of several different test series are compared and discussed. Based on investigations on passivity and pitting corrosion in alkaline solutions with different chloride contents further results in cement paste, mortar and concrete are evaluated. KW - Electrochemical noise KW - Corrosion KW - Steel in Concrete KW - Chlorides KW - Pitting Corrosion KW - Cement KW - Mortar KW - Black Steel PY - 2007 DO - https://doi.org/10.1002/maco.200704089 SN - 0947-5117 SN - 1521-4176 VL - 58 IS - 12 SP - 961 EP - 969 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-16374 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Klein, H.-H. A1 - Schade, A. A1 - Eichler, Thorsten A1 - Pruckner, F. T1 - Parkhaus "Am Gericht" in Frankfurt am Main - Eine Sanierung mit kathodischem Korrosionsschutz N2 - Parkhäuser haben nach mehreren Jahrzehnten der Nutzung häufig Sanierungsbedarf in Bezug auf die tragende Stahlbetonkonstruktion, die durch eingedrungene Chloride aus eingeschlepptem Tausalz und die hierdurch hervorgerufene Korrosion der Bewehrung in der Tragfähigkeit erheblich beeinträchtigt sein kann. Das Verfahren des kathodischen Korrosionsschutzes kann hier als elektrochemisches Instandsetzungsverfahren eine wirtschaftliche und zuverlässige Alternative zu herkömmlichen Sanierungsverfahren bieten. Voraussetzungen sind intensive Voruntersuchungen, die Kenntnis der sinnvollen Anwendungsgrenzen des Systems, eine qualitativ hochwertige bauliche Umsetzung des Systems und die Nutzung der Möglichkeiten der Überwachung des Instandsetzungserfolges durch Monitoring, was am Beispiel des Parkhauses Am Gericht in Frankfurt am Main erläutert wird. Parking garage Am Gericht in Frankfurt am Main - a refurbishment with cathodic corrosion protection. After several decades in use a refurbishment is often necessary for the bearing structure of reinforced concrete parking garages due to chlorides, which have been brought into concrete by road salt, and the resulting corrosion of the reinforcement, which may lead to a serious decrease of the bearing capacity. With the system of the cathodic protection of the reinforcement exists a cost-effective and reliable technique as an alternative to common solutions. An intensive investigation of the structure, the knowledge of the reasonable limits of the system, excellent design and execution of the construction work and the monitoring of the working system are nevertheless required, which is illustrated by the example of the parking garage Am Gericht in Frankfurt am Main. KW - Stahlbeton KW - Kathodischer Korrosionsschutz KW - Korrosion KW - Lochkorrosion KW - Instandsetzung KW - Elektrochemische Verfahren PY - 2007 DO - https://doi.org/10.1002/bate.200710040 SN - 0932-8351 SN - 1437-0999 SN - 0005-6820 SN - 0341-1052 SN - 0932-6359 SN - 0932-8351 VL - 84 IS - 7 SP - 465 EP - 476 PB - Ernst & Sohn CY - Berlin AN - OPUS4-17871 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Burkert, Andreas T1 - EIS-Messungen zur Analyse von Korrosionssystemen T2 - GfKORR-Arbeitskreis "Prüf- und Untersuchungsverfahren", IFAM CY - Bremen, Germany DA - 2005-04-11 PY - 2005 AN - OPUS4-7314 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Isecke, Bernd A1 - Klein, H.-H. T1 - Application of thermal sprayed zinc anode for CP of a multi-storey-car-park T2 - EUROCORR 2009 CY - Nice, France DA - 2009-09-06 KW - Cathodic protection KW - Thermal sprayed zinc KW - Multi-storey-car-park KW - Service life PY - 2009 IS - Paper 7862 SP - 1 EP - 14 AN - OPUS4-20237 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Isecke, Bernd A1 - Faulhaber, Armin A1 - Weidauer, Kathleen T1 - The Impact of Decreasing Chloride Concentration on the Corrosion State of Steel in Alkaline Solution T2 - IS 2009 CY - Chemnitz, Germany DA - 2009-10-22 PY - 2009 AN - OPUS4-20216 LA - deu 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 - Eichler, Thorsten A1 - Isecke, Bernd A1 - Wilsch, Gerd A1 - Faulhaber, Armin A1 - Weidauer, Kathleen T1 - The effect of chloride depletion on the corrosion state of steel in alkaline environment T2 - CONSEC 2010 CY - Mérida, Mexico DA - 2010-06-07 PY - 2010 AN - OPUS4-21612 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 - CHAP A1 - Isecke, Bernd A1 - Eichler, Thorsten A1 - Fischer, Joachim ED - Gieler-Breßmer, Susanne T1 - Möglichkeiten des kathodischen Korrosionsschutzes in karbonatisiertem 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 - 15 EP - 22 AN - OPUS4-20918 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Isecke, Bernd T1 - Untersuchungen zu den sekundären Schutzmechanismen beim kathodischen Korrosionsschutz von Stahl in Beton T2 - Doktorandensymposium 2010 des DAfStb CY - Kaiserslautern, Germany DA - 2010-11-11 PY - 2010 AN - OPUS4-21236 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Eichler, Thorsten A1 - Isecke, Bernd A1 - Faulhaber, A. A1 - Pruckner, F. T1 - Die sekundären Schutzmechanismen des kathodischen Korrosionsschutzes von Stahl in Beton und ihre Bedeutung für die Praxis PY - 2012 SN - 2191-9798 VL - 9 SP - 672 EP - 675 PB - Vulkan CY - Essen AN - OPUS4-26580 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Isecke, Bernd T1 - Kathodischer Korrosionsschutz von Stahl in Beton - Möglichkeiten und Grenzen mit praktischen Beispielen T2 - 23. Informationsseminar Bauwerke instandsetzen - heute und morgen CY - Bad Nauheim, Germany DA - 2012-11-07 PY - 2012 AN - OPUS4-26770 LA - deu 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 - 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 - Savija, B. A1 - Schlangen, E. A1 - Pacheco, J. A1 - Millar, Steven A1 - Eichler, Thorsten A1 - Wilsch, Gerd T1 - Chloride ingress in cracked concrete: a laser induced breakdown spectroscopy (LIBS) study N2 - Cracks are always present in reinforced concrete structures. In the presented research, influence of mechanical cracks on chloride ingress is studied. A compact reinforced concrete specimen was designed, mimicking the cracking behaviour of beam elements. Cracks of different widths were induced by means of mechanical loading. These cracked specimens were then subjected to weekly cycles of wetting and drying with NaCl solution. After the exposure, the specimens were cut, and chloride distributions were determined using Laser Induced Breakdown Spectroscopy (LIBS), an innovative technique which enables simultaneous determination of different elements with high spatial resolution and minimal specimen preparation. By combining element distributions of different elements, it is possible to discriminate between coarse aggregate particles, and the mortar matrix. It was found that the wider the crack is, the higher the ingress of chloride ions. This was, however, different for two tested concrete mixes. Due to highly inhomogeneous chloride distribution around the cracks, use of fine-scale experimental techniques for chloride mapping is advised, based on the presented study. KW - LIBS KW - Concrete KW - Chloride KW - Ingress KW - Cracks PY - 2014 DO - https://doi.org/10.3151/jact.12.425 SN - 1346-8014 VL - 12 IS - 10 SP - 425 EP - 442 CY - Tokyo AN - OPUS4-31932 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd A1 - Eichler, Thorsten A1 - Millar, Steven A1 - Schaurich, Dieter ED - Grantham, M. ED - Basheer, P. A. M. ED - Magee, B. ED - Soutsos, M. T1 - Laser induced breakdown spectroscopy (LIBS) - alternative to wet chemistry and micro-XRF N2 - Laser Induced Breakdown Spectroscopy (LIBS) is a combination of laser ablation, plasma formation and optical emission spectroscopy. The possibility of direct measurements on the sample surface, the minimum of necessary sample preparation and the automated setup allows for fast investigations of building materials. In combination with a scanning technique (translation stage or scanning mirrors head) the element distribution can be evaluated in consideration of the material's heterogeneity. LIBS measurements are also time-and cost-saving. The ingress profile of chlorine on a 50mm diameter concrete core up to a depth of 50mm can be measured and evaluated in less than 10 minutes. The results are normally referred to the evaporated mass, which is approximately the cement mass of the specific concrete. As a completion to micro XRF measurements also light elements like sodium or hydrogen can be detected. The spatial resolution of the measurement may reach 50 ìm at a maximum measurement frequency of up to 100 Hz. On the basis of calibration curves, results can be quantified. T2 - Concrete Solutions 2014 CY - Belfast, UK DA - 01.09.2014 KW - LIBS KW - Concrete KW - Alkali-silica reaction (ASR) KW - Chlorine KW - Sodium PY - 2014 SN - 978-1-138-02708-4 SP - 611 EP - 615 PB - CRC Press AN - OPUS4-31722 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd A1 - Eichler, Thorsten A1 - Millar, Steven A1 - Wiggenhauser, Herbert T1 - Laser induced breakdown spectroscopy (LIBS) - visualization of ion transport processes in concrete N2 - 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 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 with mm resolution. Thus the heterogeneity of the material may be considered. 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 minimize the liability for errors. All elements are detectable. Results can be quantified after calibration. 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, sulfur, lithium and hydrogen. In addition 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 close to practical application on-site. T2 - SMT 2014 - NDE/NDT for highways and bridges - Structural materials technology CY - Washington, DC, USA DA - 25.08.2014 KW - LIBS KW - Concrete KW - Alkali-silica reaction (ASR) KW - Chlorine KW - Sodium KW - Sulfur PY - 2014 SN - 978-1-57117-342-3 SP - 364 EP - 371 AN - OPUS4-31724 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Isecke, Bernd A1 - Klein, H.-H. T1 - Application of Thermal Sprayed Zinc Anode for CP of a Multi-Storey-Car-Park T2 - EUROCORR 2009 CY - Nice, France DA - 2009-09-06 PY - 2009 AN - OPUS4-19549 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Eichler, Thorsten A1 - Isecke, Bernd A1 - Faulhaber, Armin ED - Gieler-Breßmer, S. T1 - Die sekundären Schutzmechanismen des kathodischen Korrosionsschutz von Stahl in Beton und ihre Bedeutung für die Praxis T2 - 8. Symposium "Kathodischer Korrosionsschutz von Stahlbetonbauwerken" CY - Ostfildern, Deutschland DA - 2010-11-18 KW - Chloridmigration KW - pH-Wertänderung KW - Repassivierung KW - Kathodischer Korrsoionsschutz KW - Stahlbeton PY - 2010 SN - 3-924813-88-4 SP - 3 EP - 7 AN - OPUS4-22878 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Isecke, Bernd T1 - Untersuchungen zur Chloridmigration beim kathodischen Korrosionsschutz von Stahl in Beton T2 - IS 2009 CY - Chemnitz, Germany DA - 2009-10-22 PY - 2009 AN - OPUS4-20362 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Isecke, Bernd T1 - Kathodischer Korrosionsschutz von Stahl in Beton - Grundlagen, Planung, Ausführung T2 - Betoninstandsetzungstagung der MPA-Bremen CY - Bremen, Germany DA - 2010-06-17 PY - 2010 AN - OPUS4-21507 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 - CONF A1 - Eichler, Thorsten A1 - Isecke, Bernd A1 - Mietz, Jürgen T1 - Einsatz von elektrochemischen Instandsetzungsverfahren (EISV): Systeme und Anwendungsgebiete T2 - Bau und Wissen - Fachveranstaltung Nr. 104681 "Alternative Instandsetzungsverfahren von Stahlbetonbauwerken im Hoch- und Tiefbau" CY - Möriken-Wildegg, Switzerland DA - 2010-11-09 PY - 2010 AN - OPUS4-22449 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Faulhaber, Armin A1 - Isecke, Bernd T1 - Die sekundären Schutzmechanismen beim KKSB und ihre Bedeutung für die Praxis T2 - 8. Symposium Kathodischer Korrosionsschutz von Stahlbetonbauwerken CY - Ostfildern, Germany DA - 2010-11-18 PY - 2010 AN - OPUS4-22450 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Isecke, Bernd T1 - Investigations on the impact of decreasing chloride concentration on the corrosion state of reinforcing steel in alkaline environment T2 - EUROCORR 2010 CY - Moscow, Russia DA - 2010-09-13 PY - 2010 AN - OPUS4-22629 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eichler, Thorsten A1 - Isecke, Bernd A1 - Raupach, M. T1 - Time Dependency of Current and Potential Distribution during the Cathodic Protection of RC Structures T2 - EUROCORR 2011 CY - Stockholm, Sweden DA - 2011-09-04 PY - 2011 AN - OPUS4-24115 LA - deu 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 - TY - JOUR A1 - Millar, Steven A1 - Wilsch, Gerd A1 - Eichler, Thorsten A1 - Gottlieb, Cassian A1 - Wiggenhauser, Herbert T1 - Laser induced breakdown spectroscopy (LIBS) im Bauwesen - automatisierte Baustoffanalyse N2 - Die Laser induzierte Breakdown Spektroskopie (LIBS) bietet für die Analyse heterogener, mineralischer Baustoffe, wie z. B. Beton, deutliche Vorteile gegenüber konventionellen Methoden. Sie ermöglicht neben der Quantifizierung von Elementgehalten und -verteilungen im Baustoff auch die Differenzierung von Elementkonzentrationen innerhalb einzelner Phasen im Baustoff. So können beispielsweise die für die Alkali-Kieselsäure-Reaktion (AKR) interessanten Natriumkonzentrationen bestimmt und hinsichtlich ihrer Verteilung aufgelöst werden. Es lassen sich Natriumgehalte, welche sich in der Gesteinskörung befinden, separat von denen der Betonmatrix bestimmen. Der vorliegende Artikel befasst sich mit den Vor- und Nachteilen von LIBS als alternative Methode für die chemische Analyse von Baustoffen. Anhand von Beispielen aus der Praxis wird der derzeitige Stand der Technik dargestellt und ein Vergleich mit etablierten Messmethoden vorgenommen. Compared to conventional methods the Laser Induced Breakdown Spectroscopy (LIBS) provides significant advantages for analysis of heterogeneous, mineral building materials as e.g. concrete. Besides providing the possibility to quantify element concentrations and distributions in building materials, this technique enables also to differentiate concentrations within different phases of the material. It is possible to determine sodium concentrations and distribution directly, which e.g. is important when regarding Alkali-Silica-Reaction (ASR). Sodium contents provided by the aggregates can be distinguished from those provided by the concrete matrix. The present article is concerned with the advantages and disadvantages of LIBS as alternative method for chemical analysis of building materials. On the basis of samples from practice the current state of the art is shown and different measurement techniques will be compared. KW - Chloride KW - Alkali-Kieselsäure-Reaktion KW - AKR KW - RFA KW - Elementanalyse KW - Natrium KW - Baustoffuntersuchungen KW - Titration KW - Carbonatisierung KW - Baustoffe KW - Dauerhaftigkeit KW - Lebensdauer KW - Messsysteme KW - Qualitätssicherung KW - Alkali-silica-reaction KW - XRF KW - Element analysis KW - Sodium KW - Building materials analysis KW - Potentiometric titration KW - Carbonation KW - Bauwerkserhaltung/Instandsetzung KW - Korrosion PY - 2015 DO - https://doi.org/10.1002/best.201500030 SN - 0005-9900 SN - 1437-1006 VL - 110 IS - 8 SP - 501 EP - 510 PB - Ernst CY - Berlin AN - OPUS4-34580 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 - Savija, B. A1 - Pacheco, J. A1 - Schlangen, E. A1 - Millar, Steven A1 - Eichler, Thorsten A1 - Wilsch, Gerd ED - Van Breugel, K. ED - Koenders, E.A.B. T1 - Chloride ingress in cracked concrete studied using laser induced breakdown spectroscopy N2 - Cracks are always present in reinforced concrete structures. In the presented research, influence of mechanical cracks on chloride ingress is studied. A compact reinforced concrete specimen was designed, mimicking the cracking behaviour of beam elements. Cracks of different widths were induced by means of mechanical loading. These cracked specimens were then subjected to weekly cycles of wetting and drying with NaCl solution. After the exposure, the specimens were cut, and chloride distributions were determined using Laser Induced Breakdown Spectroscopy (LIBS), an innovative technique which enables simultaneous determination of different elements with high spatial resolution and minimal specimen preparation. By combining element distributions of different elements, it is possible to discriminate between coarse aggregate particles, and the mortar matrix. It was found that the wider the crack is, the higher the ingress of chloride ions. This was, however, different for two tested concrete mixes. Due to highly inhomogeneous chloride distribution around the cracks, use of fine-scale experimental techniques for chloride mapping is advised, based on the presented study. T2 - 1st Ageing of materials & structures 2014 conference CY - Delft, The Netherlands DA - 26.05.2014 KW - Chloride ingress KW - Concrete cracking KW - LIBS PY - 2014 SN - 978-94-6186-313-3 SP - 140 EP - 146 AN - OPUS4-31150 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Eichler, Thorsten A1 - Isecke, Bernd A1 - Bäßler, Ralph T1 - Investigations on the re-passivation of carbon steel in chloride containing concrete in consequence of cathodic polarisation N2 - Although the complex changes at the steel-concrete interface due to cathodic polarisation are widely acknowledged to have a beneficial influence concerning the cathodic protection (CP) of steel in concrete, some questions concerning the repassivation of carbon steel in consequence of cathodic polarisation are still not satisfactorily clarified. In the recent literature, some indications are presented that repassivation occurs after a certain time of polarisation. Therefore, the investigations discussed in this paper aim to clarify, to what extent the re-passivation of carbon steel due to cathodic polarisation occurs, and if the ennoblement of OCP is a sufficient indication for repassivation. In a first step, the corrosion state of five nominal equal test specimens was determined by electrochemical impedance spectroscopy (EIS). After determining the initial corrosion state by evaluating the charge transfer resistance and the polarisation resistance, respectively, the specimens were polarised cathodically. Impedance data were recorded before, during and after polarisation. The impedance data were evaluated by equivalent circuit fitting with special attention to charge transfer resistances and the impact of diffusion on the corrosion and polarisation behaviour. The results indicate that the reduction of oxides and oxygen diffusion during cathodic polarisation has strong impact on the systems behaviour and that repassivation effects occur after switching off the polarisation current and during depolarisation, respectively. KW - Steel in concrete KW - Cathodic protection KW - Pitting corrosion KW - Mild steel KW - Electrochemical impedance spectroscopy KW - Chlorides KW - Corrosion KW - High alkaline environment KW - Reinforced concrete KW - Unalloyed steel KW - Passivity PY - 2009 DO - https://doi.org/10.1002/maco.200805142 SN - 0947-5117 SN - 1521-4176 VL - 60 IS - 2 SP - 119 EP - 129 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-18808 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -