TY - CONF A1 - Harnisch, J. T1 - The new DGZfP Specification B12 N2 - The corrosion of steel in reinforced concrete structures is one of the main threats to their durability. Based on the scientific achievements of the past decades the knowledge about the deterioration mechanisms and possible repair strategies for corrosion induced damages have found their way into practice. It is common sense, that a detailed assessment of the structure is the foundation for a successful repair measure. In addition to the “traditional” singular on-site-procedures such as measurement of concrete cover, carbonation depth, half-cell potentials and chloride contents the monitoring of corrosion related parameters has gained in importance over the past few years. The advantages of a corrosion monitoring are obvious. In new buildings, structural elements which cannot be assessed after completion (e.g. tunnel segments), or members with electrically isolating coatings can be monitored by means of integrated sensors providing an insight into the development of crucial parameters such as electrochemical potentials, corrosion currents and the electrical resistivity of the concrete. A less known but very beneficial field of application is the use of corrosion monitoring as an integral part of a repair measure based on principles such as the cathodic protection of steel in concrete (CP) or increasing the electrical resistivity of the concrete (IR). By implementing a corrosion monitoring system, it is possible to survey the time dependent effect of the repair measure on the corrosion process which may lead to a confirmation of successful repair measure or to a modification of the repair strategy. As the principle of cathodic protection for steel in concrete is a recognized repair measure today, the number of applications increases steadily and thus increasing the relevance for corrosion monitoring. Nevertheless, no standards or guidelines concerning the corrosion monitoring are available in Germany today, making it difficult to implement corrosion monitoring in common practice. With this in mind an international task group formed to develop the specification B12 “Corrosion Monitoring of Reinforced and Prestressed Concrete Structures” published by the German Society for Non-Destructive Testing, DGZfP, spring 2018. This paper will present the new specification B12 by highlighting the basic measurement principles and illustrating the potentials of corrosion monitoring for new and existing concrete structures by means of case studies. T2 - SMAR 2019 CY - Potsdam, Germany DA - 27.08.2019 KW - Corrosion KW - Monitoring PY - 2019 AN - OPUS4-48805 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ebell, Gino T1 - Potential mapping at concrete structures N2 - Potentialmapping is an electrochemical measurement for the detection of active corroding reinforcement at concrete structures T2 - NDT-E Workshop CY - Berlin, Germany DA - 12.06.20196 KW - Korrosion KW - Potentialfeldmessung KW - Corrosion PY - 2019 AN - OPUS4-48278 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ebell, Gino T1 - Potentialmessung im Stahlbetonbau N2 - Durch das alkalische Porenwassermilieu ist Stahl im Beton vor Korrosion geschützt. Unter ungünstigen Umgebungsbedingungen (Karbonatisierung, Chlorideintrag) kann die passive Deckschicht auf der Stahloberfläche zerstört werden. Im weiteren Verlauf können sich korrosionsbedingte Folgeschäden, wie Risse und Abplatzungen am Bauwerk ergeben. Um notwendige Sanierungsmaßnahmen sind frühzeitige und weitgehend zerstörungsfrei ermittelte Informationen über das aktuelle Korrosionsverhalten der Stahlbewehrung von großer Bedeutung. Die Potentialfeldmessung ist ein etabliertes und weit verbreitetes Verfahren zur Beurteilung des Korrosionszustandes der Bewehrung in Stahlbetonbauwerken. Mit Hilfe dieses Verfahrens können Bereiche aktiv korrodierender Bewehrung zerstörungsfrei lokalisiert werden. In der Regel kommt diese Messmethode bei der Detektion chloridinduzierter Korrosion zum Einsatz. T2 - KKS-Lehrgang CY - TAE Esslingen, Germany DA - 06.05.2019 KW - Korrosion KW - Potentialfeldmessung KW - Corrosion KW - Concrete PY - 2019 AN - OPUS4-47937 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Angst, U.M. A1 - Geiker, M.R. A1 - Alonso, M.C. A1 - Polder, R. A1 - Isgor, O.B. A1 - Elsener, B. A1 - Wong, H. A1 - Michel, A. A1 - Hornbostel, K. A1 - Gehlen, C. A1 - François, R. A1 - Sanchez, M. A1 - Criado, M. A1 - Sørensen, H. A1 - Hansson, C. A1 - Pillai, R. A1 - Mundra, Shishir A1 - Gulikers, J. A1 - Raupach, M. A1 - Pacheco, J. A1 - Sagüés, A. T1 - The effect of the steel-concrete interface on chloride-induced corrosion initiation in concrete: a critical review by RILEM TC 262-SCI N2 - The steel–concrete interface (SCI) is known to influence corrosion of steel in concrete. However, due to the numerous factors affecting the SCI—including steel properties, concrete properties, execution, and exposure conditions—it remains unclear which factors have the most dominant impact on the susceptibility of reinforced concrete to corrosion. In this literature review, prepared by members of RILEM technical committee 262-SCI, an attempt is made to elucidate the effect of numerous SCI characteristics on chloride-induced corrosion initiation of steel in concrete. We use a method to quantify and normalize the effect of individual SCI characteristics based on different literature results, which allows comparing them in a comprehensive context. It is found that the different SCI characteristics have received highly unbalanced research attention. Parameters such as w/b ratio and cement type have been studied most extensively. Interestingly, however, literature consistently indicates that those parameters have merely a moderate effect on the corrosion susceptibility of steel in concrete. Considerably more pronounced effects were identified for (1) steel properties, including metallurgy, presence of mill scale or rust layers, and surface roughness, and (2) the moisture state. Unfortunately, however, these aspects have received comparatively little research attention. Due to their apparently strong influence, future corrosion studies as well as developments towards predicting corrosion initiation in concrete would benefit from considering those aspects. Particularly the working mechanisms related to the moisture conditions in microscopic and macroscopic voids at the SCI is complex and presents major opportunities for further research in corrosion of steel in concrete. KW - Steel-concrete interface KW - Interfacial transition zone KW - Durability KW - Corrosion KW - Inhomogeneity KW - Variability PY - 2019 DO - https://doi.org/10.1617/s11527-019-1387-0 VL - 52 IS - 4 SP - 88-1 EP - 88-25 PB - Springer Nature AN - OPUS4-48689 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ebell, Gino T1 - Innovative Korrosionsforschung N2 - Darstellung innovativer, kombinierter Messverfahren zur Bestimmung spezifischer elektrochemischer Kennwerte. T2 - AK Korrosionsschutz im konstruktiven Ingenieurbau CY - Frankfurt am Main, Germany DA - 18.10.2019 KW - Korrosion KW - Corrosion PY - 2019 AN - OPUS4-49329 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ebell, Gino T1 - Inhibition of hydrogen evolution on galvanized reinforcement in fresh concrete by addition of potassium permangante N2 - Due to the EUdirective53/2003/EEC,which has been in force since 17th January, 2005, restricts the soluble chromate content in cements to amaximum value of 2ppm. This ammount is to low to inhibit the hydrogen evolutuion by the cathodic partial reaction in fresh concrete. T2 - Eurocorr 2019 CY - Sevilla, Spain DA - 09.09.2019 KW - Corrosion KW - Galvanized reinforcement KW - Hydrogen PY - 2019 AN - OPUS4-48934 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Ebell, Gino T1 - Chloride induced corrosion of steel reinforcement in alkali activated fly ash mortars N2 - Electrochemical investigations to determine the chloride treshhold to induce pitting corrosion at steel reninforcement. T2 - Eurocorr 2019 CY - Sevilla, Spain DA - 09.09.2019 KW - Corrosion KW - Concrete PY - 2019 AN - OPUS4-48935 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Burkert, Andreas A1 - Ebell, Gino A1 - Eichler, T. A1 - Hariri, K. A1 - Harnisch, J. A1 - Keßler, S. A1 - Mayer, T. A1 - Meier, J. A1 - Mietz, Jürgen A1 - Reichling, K. A1 - Sodeikat, C. T1 - Electrochemical half-cell potential measurements for the detection of reinforcement corrosion N2 - This specification describes the application of electrochemical half‐cell potential measurements (frequently also called potential mapping) for the detection of reinforcement corrosion in reinforced concrete structures. Areas of corroding reinforcement steel can be located in a nondestructive manner by means of this procedure. Half‐cell potential measurements are used in order to detect chloride‐induced corrosion. However, it is not recommended in order to assess the risk of carbonation‐induced corrosion. For this purpose the determination of the carbonation depth and the concrete cover appear to be more appropriate. The content of this specification exclusively refers to the application of mobile, local variable reference electrodes, which are only placed on the concrete surface while measuring. The technique distinguishes itself thereby from the range of corrosion monitoring systems with stationary installed reference electrodes and sensor systems, respectively, whereby it is possible to continuously track measurements within the area of the installed electrodes. However, these methods are not dealt with in this specification. KW - Monitoring KW - Corrosion KW - Reinforcement PY - 2014 SN - 978-3-940283-72-6 SP - B 03, 1 EP - 19 PB - DGZfP CY - Berlin AN - OPUS4-40419 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Henning, Ricky A1 - Sturm, Patrick A1 - Keßler, S. A1 - Gluth, Gregor T1 - Corrosion of hybrid alkaline cements in saline solution simulating evaporite rock – effect of the Portland clinker content N2 - Two hybrid alkaline cements (HAC) based on Portland clinker, ground granulated blast furnace slag (GGBFS), fly ash and sodium sulfate, as well as an alkali-activated GGBFS/fly ash blend and a Portland cement paste were exposed to a saturated saline solution for 70 days. The combined chemical attack of chloride, magnesium and sulfate ions and the associated changes of the phase assemblage of the materials were studied by X-ray diffraction, thermal analysis and spatially resolved X-ray fluorescence spectroscopy. The experimental results revealed dissolution of ettringite, C-N-A-S-H and calcite, and the formation of gypsum, Kuzel's salt and Friedel's salt; thermodynamic modeling indicated the formation of M-S-H. The resistance of the HAC against attack by the saline solution increased with Portland clinker fraction. The capacity of portlandite to maintain pH at values above 10 is found to be a major factor controlling the resistance of HAC against corrosion in the saline solution. KW - Hybrid cements KW - Alkali-activated materials KW - Magnesium chloride KW - Corrosion KW - Salt attack PY - 2023 DO - https://doi.org/10.1016/j.cemconres.2023.107215 SN - 0008-8846 SN - 1873-3948 VL - 172 SP - 1 EP - 14 PB - Elsevier Ltd. AN - OPUS4-57638 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hlavacek, Petr A1 - Gluth, Gregor A1 - Reinemann, Steffi A1 - Ebell, Gino A1 - Kühne, Hans-Carsten A1 - Mietz, Jürgen T1 - Corrosion of steel reinforcement in geopolymer mortars - carbonation resistance, chloride migration, and preliminary corrosion potential data N2 - Alkali-activated materials such as geopolymers are currently receiving a lot of attention because of their potential to be used as binders for concrete with advantageous engineering properties and reduced manufacturing CO2 emissions. Knowledge of the durability of steel in these concretes and related properties of alkali-activated materials is a prerequisite for their application as building materials, if they are to be used for steel reinforced elements. However, to date only limited data exists on this topic. The present contribution focuses on durability-related transport properties of geopolymer-based mortars (as model systems for concrete). We report results of accelerated carbonation, rapid chloride migration (RCM) and air permeability measurements as well as porosity data for fly ash-based geopolymer mortars, including mixes containing ground granulated blast furnace slag (GGBFS). In addition, we report polarization resistance data and corrosion potential vs. time curves for carbon steel bars embedded in two of the fly ash-based geopolymer mortars and a CEM I-based mortar (as reference). Despite comparable total porosities, the carbonation depths, the chloride migration coefficients and the air permeabilities of the mortars differed significantly. In general, the addition of GGBFS to the binders improved the performance (decreased transport coefficients); however, this was not found to be true for the air permeability in all cases. This latter effect can be explained by drying damage of the C-(A-)S-H gel in GGBFS-containing binders. On the other hand, low transport coefficients can also be achieved by optimization of the binder formulation without the addition of GGBFS, which is also reflected in the material’s air permeability. Thus, there exists no simple correlation between air permeability (of harshly dried mortars) and durability-related transport coefficients for the studied alkali-activated materials. The corrosion potential vs. time curves in combination with polarization resistance values reveal that the steel reinforcement in geopolymer mortars assumed a passive state. However, this happened considerably later than for steel in CEM I-based mortars. The free corrosion potential of carbon steel reinforcement in the geopolymer mortars had different values than the free corrosion potential values for the CEM I-based mortar for both the active and the passive state; possible reasons for this behavior are discussed. T2 - EUROCORR 2017 CY - Prague, Czech Republic DA - 03.09.2017 KW - Geopolymers KW - Alkali-activated materials KW - Corrosion KW - Steel reinforcement KW - Concrete PY - 2017 SP - Paper 87351, 1 EP - 7 AN - OPUS4-41870 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 -