TY - CONF A1 - Gottlieb, Cassian T1 - Cluster algorithm for the evaluation of heterogeneous materials by LIBS N2 - The laser-induced breakdown spectroscopy (LIBS) is a fast method to provide multi-elemental analysis of any sample. At the Federal Institute for Materials Research and Testing (BAM) the LIBS technique is applied on building materials to measure ingress profiles of harmful species like chloride and alkalis. The ingress depth and the quantitative amount is important for the evaluation of the potential for damage processes like the alkali-silica reaction or chloride-induced corrosion. Concrete as an example is a highly heterogeneous material with 1/7 cement (major component CaO) and 6/7 aggregates (SiO2) with different grain sizes. Due to a scanning procedure a two dimensional element distribution of a concrete surface can be measured. In order to have an automated Separation method to evaluate heterogeneous materials, different cluster algorithm have been tested. Best results have been achieved with the Expectation-Maximization-Algorithm (EM-Algorithm). T2 - Chemometrics in analytical chemistry CY - Barcelona, Spain DA - 06.06.2016 KW - LIBS KW - Concrete KW - Multivariate analysis PY - 2016 AN - OPUS4-36471 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Advances in ultrasonic testing and monitoring of concrete structures N2 - Recent years have seen extended use of ultrasonic techniques for concrete infrastructure assessement. They are applied for quality assurance and condition assessement at bridges, power plants, dams and other important objects. However, there are still a couple of significant limitations. They include, but are not limited to depth of penetration, imaging complex structures or early stage detections of distributed damage. The talk will give information on recent research in this area. Specifically, the application of the unique deep penetration system LAUS is shown. Ultrasonic monitoring using embedded transducers to check for subtle and sudden changes in the material is introduced as well. Comments on initiatives for validation, standardization and certification will be given. T2 - 341e Conférence CERES CY - Online meeting DA - 26.10.2020 KW - Concrete KW - Ultrasound KW - Imaging KW - Monitoring PY - 2020 AN - OPUS4-51463 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Gottlieb, Cassian A1 - Bohling, Christian A1 - Wilsch, Gerd T1 - New possibilities for concrete analysis 4.0 with the Laser-Induced Breakdown Spectroscopy (LIBS) N2 - In civil engineering the damage assessment of concrete infrastructures is an important task to monitor and ensure the estimated life-time. The aging of concrete is caused by different damage processes like the chloride induced pitting corrosion of the reinforcement. The penetration depth and the concentration of harmful species are crucial factors in the damage assessment. As a highly cost and time-consuming standard procedure, the analysis of concrete drill cores or drilling by wet-chemistry is widely used. This method provides element concentration to the total mass as aggregates and binder are homogenized. In order to provide a method that is capable to detect the element concentration regarding the cement content only, the laser-induced breakdown spectroscopy (LIBS) will be presented. The LIBS method uses a focused pulsed laser on the sample surface to ablate material. The high-power density and the laser-material interaction causes a laser-induced plasma that emits elemental and molecular line emission due to energy transition of the excited species in the plasma during the cooling phase. As each element provides element-specific line emission, it is in principle possible to detect any element on the periodic table (spectroscopic fingerprint) with one laser shot. In combination with a translation stage the sample under investigation can be spatially resolved using a scan raster with a resolution up to 100 µm (element mapping). Due to the high spatial resolution, the element distribution and the heterogeneity of the concrete can be evaluated. By using chemometrics the non-relevant aggregates can be excluded from the data set and the element concentration can be quantified and referred to a specific solid phase like the binding matrix (cement) only. In order to analyze transport processes like diffusion and migration the twodimensional element distributions can provide deep insight into the transport through the pore space and local enrichments of elements. As LIBS is a multi-elemental method it is also possible to compare the ingress and transport process of different elements like Cl, Na, K, S, C, and Li simultaneously and evaluate cross-correlations between the different ions. Furthermore, the element mapping allows to visualize the transport along cracks. This work will show the state of the art in terms of hardware and software for an automated LIBS system as well as different application for a concrete analysis 4.0. Focus will be the application of LIBS for a fast concrete analysis. T2 - SMAR 2019 CY - Potsdam, Germany DA - 27.08.2019 KW - Damage KW - LIBS KW - Concrete KW - Mapping KW - Chlorine PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-517282 UR - https://www.ndt.net/?id=24963 SN - 1435-4934 VL - 25 IS - 1 SP - 1 EP - 8 PB - NDT.net CY - Kirchwald AN - OPUS4-51728 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Krankenhagen, Rainer A1 - Zirker, Stefan A1 - Joniertz, Florian T1 - Determination of thermal parameters of concrete by active thermographic measurements N2 - The knowledge of the thermal parameters of a particular concrete is essential for thermal design of a building, but also could help to identify and assess the state of a concrete structure. Active thermography has the potential to be applied onsite and to provide a fast investigation of thermal properties. In this work, three different concrete samples were investigated by active thermography in reflection and in transmission setup. It was found that this method yields the same results without direct contact as the Transient Plane Source (TPS) method as an established inspection tool. KW - Concrete KW - Effusivity KW - Thermal diffusivity KW - Photothermal KW - Thermography KW - Hot disc method KW - Parker method KW - Onsite inspection PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-543781 DO - https://doi.org/10.1007/s10921-022-00861-6 SN - 0195-9298 SN - 1573-4862 VL - 41 IS - 1 SP - 1 EP - 20 PB - Springer AN - OPUS4-54378 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kruschwitz, Sabine T1 - Verbesserung der Kreislaufwirtschaft im Bauwesen durch Bauwerksdiagnose: Ein Einblick in das Projekt REINCARNATE N2 - Das EU-finanzierte Projekt REINCARNATE, im Rahmen des Horizont Europa Programms, setzt neue Maßstäbe in der Kreislaufwirtschaft des Bauwesens durch den Einsatz fortschrittlicher Bauwerksdiagnose-Tools. Diese Werkzeuge, insbesondere die Zerstörungsfreie Prüfung (ZfP), spielen eine zentrale Rolle bei der Förderung der Zirkularität in der Baubranche. Die ZfP ermöglicht es, die Qualität und Eignung von Baumaterialien präzise zu bestimmen, ohne diese zu beschädigen. Dies ist entscheidend für die Wiederverwendung und das Recycling von Baustoffen und trägt wesentlich zur Reduzierung des Bauabfalls bei. Durch die Integration dieser Technologie in die Planungs- und Entwurfsphase können Architekten und Ingenieure aktiv einen nachhaltigeren Bauprozess fördern. REINCARNATE verbindet diese Diagnosemethoden mit digitalen Innovationen wie der Technologie des digitalen Zwillings und KI-gesteuerten Lösungen. Diese Kombination ermöglicht eine noch genauere und effizientere Bewertung und Nutzung von Baustoffen, was die Wiederverwendbarkeit und das Recycling verbessert. Im Rahmen des Projekts werden elf Demonstrationsprojekte in ganz Europa umgesetzt, die die praktische Anwendung dieser Technologien zeigen. Diese Projekte demonstrieren, wie ZfP und digitale Werkzeuge zusammenwirken, um Materialien, die traditionell als Abfall angesehen werden, in wertvolle Ressourcen umzuwandeln. Das Ziel von REINCARNATE ist eine 80-prozentige Verringerung der Bauabfälle und eine 70-prozentige Reduzierung des CO2-Fußabdrucks. Mit diesem Beitrag demonstrieren wir eine klare, umsetzbare Anleitung für die Bauindustrie, wie Innovationen in die Praxis umgesetzt werden können. Wir präsentieren greifbare Strategien zur Implementierung nachhaltiger, zirkulärer Praktiken im Bauwesen und markiert einen Wendepunkt in Richtung einer nachhaltigeren Bauindustrie. T2 - Fachtagung Bauwerksdiagnose 2024 CY - Berlin, Germany DA - 29.02.2024 KW - Concrete KW - Recycling KW - BIM KW - AI KW - NDT PY - 2024 AN - OPUS4-60620 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wilsch, Gerd A1 - Gottlieb, Cassian A1 - Millar, Steven A1 - Wiggenhauser, Herbert T1 - Laser induced breakdown spectroscopy (LIBS) – automated 2D chemical analysis of 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 with 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) 2D element distributions of harmful species like chlorides and alkalis are evaluated with a sub-mm resolution. By scanning a surface of typically 100 mm x 100 mm the heterogeneity of the material may be considered. LIBS is capable to identify hot spots in element concentration with a resolution of 0.1 mm or even smaller. A LIBS-system for the on-site application on building materials is, in cooperation with system developers and companies which will use this technique for investigation on real structures, under test at BAM. We present an example. Further work will focus on providing guidelines to establish LIBS as a standard procedure for chemical investigations of building materials. T2 - NDE / NDT for Highway and Bridges: Structural Materials Technology CY - Portland, Oregon, USA DA - 29.08.2016 KW - LIBS KW - Concrete KW - Chloride KW - Chemical analysis PY - 2016 SN - 978-1-57117-392-8 SP - 155 EP - 160 PB - The American Society for Nondestructive Testing, Inc. CY - Columbus, OH 43228-0518, USA AN - OPUS4-37679 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Niederleithinger, Ernst T1 - Coda wave interferometry used for monitoring of concrete constructions N2 - Ultrasonic transmission measurements on concrete; embedded transducers; coda wave interferometry to check for subtle chnages in velocity as indicator for various loads or deterioration. T2 - 76. Jahrestagung der Deutschen Geophysikalischen Gesellschaft CY - Münster, Germany DA - 14.03.2016 KW - Ultrasound KW - Transmission KW - Coda wave interferometry KW - Concrete KW - Load PY - 2016 AN - OPUS4-37721 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gottlieb, Cassian T1 - Damage assessment of infrastructures using a mobile LIBS system N2 - Reinforced concrete structures like bridges and parking decks are subject of corrosion of the reinforcement if chlorides from thawing salts or sea water penetrating into the concrete. For the determination of the expected life time normally samples are taken by borehole cuts or drilling of cores. These samples are taken to the lab and standard chemical methods are used for evaluation. As an alternative a fast and reliable onsite technique which gives results just in time is needed. In cooperation with industrial partners and BAM a mobile LIBS system for the on-site application of LIBS in civil engineering has been developed. The mobile system uses a low energy laser with a pulse energy of < 3 mJ, a wavelength of 1064 nm, a pulse width of 1.5 ns, a repetition rate of 100 Hz and a NIR-spectrometer in combination with a scanner to map areas of up 170 mm x 140 mm. In this work the correlation between exposures of the concrete surface due to chlorides and their ingress profiles will be shown. Quantitative ingress profiles are evaluated and compared with standard analysis. T2 - 9th International Conference on Laser Induced Breakdown Spectroscopy (LIBS2016) CY - Chamonix, France DA - 12.09.2016 KW - LIBS KW - Concrete KW - Mobile system KW - On-site analysis KW - Civil engineering PY - 2016 AN - OPUS4-37422 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Altenburg, Simon T1 - Thickness determination of semitransparent isolated solids using the flash method and an analytical model N2 - As groundwork for thickness determination of polymeric surface protection systems for concrete, we present a method for measuring the thickness of isolated semitransparent solids using pulse thermography both in transmission and reflection configuration. An advanced analytical model by Salazar et al. capturing semitransparency is applied. After calibration with samples of well-known thickness, the unknown thickness of samples of the same material can be obtained by fitting. T2 - QIRT 2016 CY - Gdansk, Poland DA - 04.07.2016 KW - Thermography KW - Analytical model KW - Surface protection KW - Concrete KW - Semitransparency KW - Thickness KW - Flash thermography PY - 2016 AN - OPUS4-36983 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Huschke, Philip T1 - Concrete mesostructure geometry modeling with growing and colliding hard spheres N2 - Simulations of concrete on the mesoscale require complex geometry models that resolve single aggregates. Since they fill up to 60-80% of the virtual specimen, efficient algorithms for their placement are necessary. Event-driven molecular dynamics (EDMD) algorithms using growing spheres are proven to create dense polydisperse sphere packings. In this paper, a modified EDMD algorithm is presented and compared to the widely used random sequential addition algorithm. It reaches denser aggregate packings and saves computation time at high volume fractions. When meshing the geometry, a minimal distance between the aggregates ensures undistorted elements. It is obtained by increasing the aggregate size during the placement process, which makes the packing problem more challenging. For a given aggregate volume fraction, the presented algorithm maximizes this distance and meshable mesoscale geometries for concrete specimens with more than 70% aggregate content are produced. T2 - 3rd ECCOMAS Young Investigators Conference CY - Aachen, Germany DA - 20.07.2015 KW - Concrete KW - Mesoscale KW - Geometry modeling KW - Molecular dynamics PY - 2015 AN - OPUS4-38697 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -