TY - JOUR A1 - Maierhofer, Christiane A1 - Brink, Arne A1 - Röllig, Mathias A1 - Wiggenhauser, Herbert T1 - Transient thermography for structural investigation of concrete and composites in the near surface region KW - Impulse thermography KW - Non-destructive testing KW - Quantitative analysis KW - Concrete KW - Composites KW - Civil engineering KW - Simulation KW - Finite differences PY - 2002 SN - 1350-4495 VL - 43 SP - 271 EP - 278 PB - Pergamon Press CY - Oxford AN - OPUS4-1759 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Brink, Arne A1 - Wedler, Gerd A1 - Maierhofer, Christiane A1 - Röllig, Mathias A1 - Weritz, Friederike A1 - Wiggenhauser, Herbert T1 - Active infrared thermography in civil engineering - quantitative analysis by numerical simulation N2 - The cooling-down process of building structures after heating-up with an external radiation source was analysed to detect voids inside and below the surface. Quantitative results of concrete test specimen containing voids with different sizes at various depths will be presented here. The experimental results were compared to numerical simulations performed with a Finite Difference program developed at BAM. T2 - 6th International Symposium Non-Destructive Testing in Civil Engineering (NDT-CE) CY - Berlin, Germany DA - 2003-09-16 KW - Non-destructive testing in civil engineering KW - Acitve thermography KW - Concrete KW - Voids KW - Numerical SImulation KW - Finite differences PY - 2003 UR - http://www.ndt.net/article/ndtce03/papers/p024/p024.htm SN - 3-931381-49-8 SP - 1 EP - 8(?) PB - DGZfP CY - Berlin AN - OPUS4-3403 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Maierhofer, Christiane A1 - Brink, Arne A1 - Röllig, Mathias A1 - Wiggenhauser, Herbert ED - Binda, L. T1 - Transient thermography for non-destructive investigation of building structures in the near surface region T2 - RILEM TC 177-MDT Workshop on On-Site Control and Non-Destructive Evaluation of Masonry Structures CY - Mantova, Italy DA - 2001-11-12 KW - Non-destructive testing KW - Masonry KW - Concrete KW - Impulse thermography KW - Plaster KW - Laminates PY - 2003 SN - 2-912143-34-9 N1 - Serientitel: RILEM proceedings – Series title: RILEM proceedings IS - 26 SP - 251 EP - 261 PB - RILEM Publications CY - Bagneux, France AN - OPUS4-1829 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maierhofer, Christiane A1 - Brink, Arne A1 - Röllig, Mathias A1 - Wiggenhauser, Herbert T1 - Quantitative Impulse-Thermography as Non-Destructive Testing Method in Civil Engineering - Experimental Results and Numerical Simulations N2 - Impulse-thermography is an active method for quantitative investigation of the near surface region of various structures which has recently been applied to civil engineering. It is well suited for the detection of voids and honeycombing in concrete up to concrete covers of 10 cm and more. For quantitative analysis, a computer program for numerical simulation of the heating up and cooling down processes was developed based on Finite Differences. With this program parameter studies have been performed for investigating the influence of environmental conditions, material parameters and geometry on the thermal behaviour. The comparison between experimental and simulated results enables the Inverse Solution. KW - Impulse-thermography KW - Numerical simulation KW - Non-destructive testing KW - Concrete KW - Civil engineering PY - 2005 SN - 0950-0618 VL - 19 IS - 10 SP - 731 EP - 737 PB - Elsevier CY - Oxford AN - OPUS4-3162 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Arndt, Ralf A1 - Maierhofer, Christiane A1 - Röllig, Mathias A1 - Weritz, Friederike A1 - Wiggenhauser, Herbert T1 - Structural investigation of concrete and masonry structures behind plaster by means of pulse phase thermography T2 - 7th International Conference on Quantitative Infrared Thermography (QIRT 2004) CY - Rhode-St-Genese, Belgien DA - 2004-06-05 KW - Pulse phase thermography KW - Nondestructive testing in civil engineering KW - Plaster KW - Concrete KW - Masonry KW - Delaminations KW - Voids PY - 2004 SP - I.3.1 EP - I.3.6 PB - Karman Institute for Fluid Dynamics CY - Rhode-St-Genese AN - OPUS4-4397 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Weritz, Friederike A1 - Arndt, Ralf A1 - Röllig, Mathias A1 - Maierhofer, Christiane A1 - Wiggenhauser, Herbert T1 - Investigation of concrete structures with pulse phase thermography N2 - The applicability of pulse phase thermography (PPT) for the investigation of structures is studied systematically on concrete test specimens and on a plastered sandstone column. In the test specimens, voids and delaminations are implemented in different depths and with different sizes, modelling real voids, honeycombing and debonding. Delaminations of plaster in concrete and masonry and behind tiles on concrete are investigated. PPT is based on the frequency analysis of the cooling down process of actively heated surfaces. Therefore, it is contactless and thus completely non-destructive (if overheating of the surface is prevented), fast and allows the inspection of large surface areas. The interpretation of amplitude and phase images gives semi-quantitative information about the observed defects. The phase images provide a deeper probing up to 10–15 cm in relation to the interpretation of the thermograms and to the amplitude images. In addition, the influence of surface inhomogeneities and non-uniform heating is reduced. KW - Pulse phase thermography KW - Impulse thermography KW - Concrete KW - Voids KW - Honeycombing PY - 2005 U6 - https://doi.org/10.1007/BF02481657 SN - 1359-5997 SN - 1871-6873 VL - 38 IS - 9 SP - 843 EP - 849 PB - Springer CY - Dordrecht AN - OPUS4-12300 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Arndt, Ralf A1 - Maierhofer, Christiane A1 - Röllig, Mathias T1 - Quantitative Pulse-Phase-Thermography for Masonry and Concrete Structures N2 - An advanced quantitative approach of pulse-phase-thermography for nondestructive testing in civil engineering is described in this contribution. The characteristic frequency of the maximum phase-contrast between defects and sound areas is used as a means for the characterization of its depth. The new approach is tested in the laboratory on concrete structures with defects of polystyrene. The surfaces of the structures were heated with IR-radiators for varying time periods. The presented investigations were funded by the Deutsche Forschungsgemeinschaft (DFG) and were carried out in co-operation with the Technical University of Berlin (TUB). T2 - 9th European Conference on NDT CY - Berlin, Germany DA - 2006-09-25 KW - Quantitative non-destructive investigation KW - Impulse-thermography KW - Pulse-phase-thermography KW - Blind / characteristic frequency KW - Concrete PY - 2006 SN - 3-931381-86-2 SP - 1(?) EP - 8(?) PB - European Federation for Non-Destructive Testing CY - Berlin AN - OPUS4-13793 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Arndt, Ralf A1 - Helmerich, Rosemarie A1 - Maierhofer, Christiane A1 - Röllig, Mathias ED - Forde, M. T1 - Quantitative Pulse-Phase-Thermography for Composites and Concrete Structures N2 - The active approach for non-destructive-testing in Civil Engineering (NDT-CE) with infraredthermography (IR), developed at the Federal Institute for Materials Research and Testing (BAM), is described in part one of this contribution. The active IR-approach is based on the principles of impulse- (IT) and pulse-phase-thermography (PPT). The concept is a direct result of a research project at the BAM in cooperation with the Technical University of Berlin (TUB) and was funded by the Deutsche Forschungsgemeinschaft (DFG). In the second part results of the new thermography-scanning system (thermo-scanner) of BAM on debonding of multi-layered structures, especially carbon fibre reinforced plates (CFRP) on concrete are presented. Both, the thermo-scanner developed at BAM, and the investigations carried out, are part of the EU-Project Sustainable Bridges. In the third part of the paper the characteristic frequency of the optimum phase-contrast as a means for the characterization of defects’ depth in CE by means of PPT is introduced. A new quantitative approach is tested and discussed on concrete structures with defects of polystyrene and gas concrete. T2 - 11th International Conference and Exhibiton "Structural Faults and Repair - 2006" CY - Edinburgh, Scotland, UK DA - 2006-06-13 KW - Quantitative NDT KW - Impulse-thermography KW - Pulse-phase-thermography KW - Blind / characteristic frequency KW - Concrete KW - Thermo-scanner KW - CFRP-laminates KW - Debonding KW - Voids PY - 2006 SN - 0-947644-59-8 SP - 1(?) EP - 17(?) PB - Engineering Technics Pr., CY - Edingburgh AN - OPUS4-13794 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maierhofer, Christiane A1 - Brink, Arne A1 - Röllig, Mathias A1 - Wiggenhauser, Herbert T1 - Detection of shallow voids in concrete structures with impulse thermography and radar N2 - New thermography systems enable the application of active investigation techniques, i.e. the observation of the cooling down process after heating the surface of a structure under investigation. Defects like voids in concrete having a different thermal diffusivity in comparison to the bulk material are visualised by different surface temperatures. The differences between temperature transient curves above sound regions and above inhomogeneities are expected to include information about the defect parameters. Experimental investigations with impulse thermography and radar on a concrete test specimen containing voids were analysed. Radar was used to determine the depth of the voids. The influence of size and depth of the voids on the temperature transient curves was studied for different heating times. The transient curves were also fitted with a simple semi-empirical model. KW - Impulse thermography KW - Radar KW - Non-destructive testing KW - Concrete KW - Civil engineering PY - 2003 SN - 0963-8695 VL - 36 IS - 4 SP - 257 EP - 263 PB - Butterworth-Heinemann CY - Oxford AN - OPUS4-11867 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maierhofer, Christiane A1 - Wiggenhauser, Herbert A1 - Brink, Arne A1 - Röllig, Mathias T1 - Quantitative numerical analysis of transient IR-experiments on buildings N2 - Impulse-thermography has been established as a fast and reliable tool in many areas of non-destructive testing. In recent years several investigations have been done to apply active thermography to civil engineering. For quantitative investigations in this area of application, finite difference calculations have been performed for systematic studies on the influence of environmental conditions, heating power and time, defect depth and size and thermal properties of the bulk material (concrete). The comparison of simulated and experimental data enables the quantitative analysis of defects. T2 - 7th International Workshop on Advanced Infrared Technology and Applications ; 7th AITA Conference CY - Pisa, Italy DA - 2003-09-09 KW - Impulse-thermography KW - Numerical simulation KW - Non-destructive testing KW - Concrete KW - Civil engineering PY - 2004 U6 - https://doi.org/10.1016/j.infrared.2004.03.022 SN - 1350-4495 VL - 46 IS - 1-2 SP - 173 EP - 180 PB - Pergamon Press CY - Oxford AN - OPUS4-4984 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Krankenhagen, Rainer A1 - Maierhofer, Christiane A1 - Röllig, Mathias ED - Büyüköztürk, O. ED - Tasdemir, M.A. ED - Günes, O. ED - Akkaya, Y. T1 - Thermographic investigation of delaminated plaster on concrete N2 - Active thermography is sensitive to inhomogeneities at and below the surface of objects investigated. Thus, it should be useful for detecting plaster delaminations on concrete. In this paper, the results of field and laboratory investigations into plaster-covered concrete were compared. For evaluating the bonding state of the plaster it is not sufficient to study only the thermal contrasts at the surface of the investigated objects. The experimental results suggest that the overall thermal behaviour has to be considered. KW - Active thermography KW - Bonding problems KW - Concrete KW - Plaster PY - 2013 SN - 978-94-007-0722-1 U6 - https://doi.org/10.1007/978-94-007-0723-8_112 SN - 2211-0844 N1 - Serientitel: RILEM bookseries – Series title: RILEM bookseries VL - 6 SP - 758 EP - 791 PB - Springer AN - OPUS4-28264 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Maierhofer, Christiane A1 - Krause, Martin A1 - Wöstmann, Jens A1 - Röllig, Mathias A1 - Arndt, Ralf A1 - Streicher, Doreen A1 - Kohl, C. ED - L. Binda, ED - M. di Prisco, ED - R. Felicetti, T1 - Influence of concret properties on the calibration of radar, ultrasonics and active thermography T2 - 1st International RILEM Conference, on Site Assessment of Concrete, Masonry and Timber Structures (SACoMaTiS 2008) CY - Varenna, Italy DA - 2008-09-01 KW - Concrete KW - Radar KW - Ultrasonics KW - Active thermography KW - Velocity calibration PY - 2008 SN - 978-2-35158-062-2 VL - 1 IS - PRO 59 SP - 15 EP - 24 PB - RILEM Publications AN - OPUS4-18033 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Maierhofer, Christiane A1 - Arndt, Ralf A1 - Röllig, Mathias A1 - Rieck, C. A1 - Walther, A. A1 - Scheel, H. A1 - Hillemeier, B. T1 - Application of impulse-thermography for non-destructive assessment of concrete structures N2 - Impulse-thermography is an active method for quantitative investigations of the near surface region of various structures. It has recently been applied and optimised to applications in civil engineering. By using either an internal or external heat source, parts of the structure under investigation are heated up and the transient heat flux is observed by recording the temperature change at the surface as a function of time. This method is very well suited for the detection of voids and honeycombing in concrete, up to concrete covers of 10 cm as well as for the location of delaminations in multi-layered systems (e.g. plaster on concrete, CFRP-laminates on concrete, asphalt on concrete). Also safety relevant defects like voids in tendon ducts and cracks in concrete could be recognised. KW - Non-destructive testing KW - Impulse-thermography KW - Concrete KW - CFRP-laminates KW - Delamination KW - Tendon duct KW - Voids KW - Compaction faults PY - 2006 U6 - https://doi.org/10.1016/j.cemconcomp.2006.02.011 SN - 0958-9465 SN - 1873-393X VL - 28 IS - 4 SP - 393 EP - 401 PB - Elsevier CY - Barking, Essex AN - OPUS4-12359 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Maierhofer, Christiane A1 - Röllig, Mathias T1 - Application of active thermography to the detection of safety relevant defects in civil engineering structures T2 - IRS² 2009 - 11th International conference on infrared sensors & systems CY - Nürnberg, Germany DA - 2009-05-26 KW - Non-destructive testing KW - Active thermography KW - Pulse-phase thermography KW - Concrete KW - Voids KW - Cracks KW - CFRP delaminations PY - 2009 SN - 978-3-9810993-6-2 IS - Chapter 2.2 SP - 215 EP - 220 AN - OPUS4-19873 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Maierhofer, Christiane A1 - Röllig, Mathias A1 - Arndt, Ralf A1 - Kreutzbruck, Marc ED - Thompson, D. O. ED - Chimenti, D. E. T1 - Influence of surface properties on the detection and quantification of voids in concrete structures using active thermography N2 - Impulse thermography is an active method for quantitative investigations of the near surface region of various structures. It has recently been applied and optimized to applications in civil engineering. For quantitative analysis of data recorded on the building site, the problems are manifold. Here, the influence of the different surface properties on the detection and characterization of voids and honeycombing simulated by polystyrene cubes and cubes prepared of porous concrete are demonstrated. T2 - 35th Annual Review of Progress in Quantitative Nondestructive Evaluation CY - Chicago, IL, USA DA - 2008-07-20 KW - Active thermography KW - Pulse phase thermography KW - Surface properties KW - Emissivity KW - Concrete KW - Voids KW - Honeycombing PY - 2009 SN - 978-0-7354-0629-2 SN - 0743-0760 SN - 0094-243X N1 - Serientitel: AIP conference proceedings – Series title: AIP conference proceedings IS - 1096 SP - 1505 EP - 1511 PB - American Institute of Physics CY - Melville, NY AN - OPUS4-19438 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -