SFB/TRR 280 (Design Strategies for Material-Minimised Carbon Reinforced Concrete Structures) - Image Analysis Methods in Micro-Tomography

Researcher: Frank Liebold, Franz Wagner, Matthias Hardner
Former: Ferdinand Maiwald, Ariel Rodriguez, Hannes Sardemann

This project is part of a Collaborative Research Centre SFB/TRR 280 (Design Strategies for Material-Minimised Carbon Reinforced Concrete Structures—Principles of a New Approach to Construction, subprojects D03 and S) and it is funded by the German Research Council (Deutsche Forschungsgemeinschaft, DFG). Several parts of the project will be presented in the following points.

The Project

In close cooperationmore than 20 subprojects at the Dresden and Aachen, new structural shape and design strategies are being developed and implemented. However, the carbon reinforced concrete structures must be comprehensively investigated in order to ensure their reliability. The subprojects D03 and S focus on the recording and 3D reconstruction of such samples by a µ-tomograph up to the structural analysis of the resulting data.

Computertomography

A tomography device consists of an X-ray source and an image plane, which can be seen as a camera. During the scan, a large number of projections are aquired while the object rotates.

From these images, a volumetric reconstruction of the object is obtained, which is then represented by a grayscale voxel space, wherein the elements contained in the specimen are visible.

Deep Learning based 3D Structural Analysis

The resulting reconstructions can then be analyzed in terms of their components, properties, and deformations. Quantitative structural analysis is performed using 3D Convolutional Neural Networks (CNN), as a process based on simpler algorithms is not able to confidently segment the smallest constituents.

First, the neural networks are trained in a supervised manner. This means that there must already be a segmented volume on which the network learns which structures it should segment.

However, the production of the training data is extremely time-consuming, which is why an unsupervised (without the influence of humans) learning process is developed. This eliminates the need for future processors to manually produce the training data. The goal is achieved by a 3D Generative Adversarial Network (GAN), which generates deceptively real training data.

3D Displacement Fields between Deformation States

There exist at least two volumes of different load steps of a probe.

Cross-sections of the reference and the deformed state:

In the reference volume a grid of point is defined. In order to obtain the displacement field for these points, 3D least squares matching is applied. It is a gradient based subpixel precise matching method.

Deformation Analysis

The appearance of cracks leads to discontinuities in displacement field. The following deformation vectors are determined:

Awards

• Photogrammetry award of the Nico Rüpke - Stiftung 2022 for Frank Liebold and Hans-Gerd Maas

Publications 2026

• Liebold, F., Maas, H.-G. (2026):

  Zur Korrektur von Exzentrizitäten bei der Bildellipsenmessung von Kugeln und Kreisen in der zentralperspektiven Abbildung. Tagungsband der 23. 3D-Tage 2026 vom 25.-26.02.2026 in Dresden. Hildebrant, L., Maiwald, F., Schneider, D., Sieberth, T. (Hrsg.). 158-169, http://doi.org/10.24407/KXP:1974687589.

• Liebold, F., Maas, H.-G. (2026):

  Eccentricity Correction Methods for Circular Targets in Perspective Projection. Metrology, 6(2), 28, https://doi.org/10.3390/metrology6020028

• Liebold, F., Wagner, F., Sardemann, H., Maas, H.-G. (2026):

  Automatic registration of voxel datasets using feature descriptor matching. 15th Conference on Industrial Computed Tomography, Wels, Austria (iCT 2026), https://doi.org/10.58286/32592

• Liebold, F., Maas, H.-G. (2026):

  Spherical target eccentricity correction in photogrammetric applications. ISPRS Journal of Photogrammetry and Remote Sensing, 231, 761-777, https://doi.org/10.1016/j.isprsjprs.2025.11.022

Publications 2025

• Liebold, F., Neef, T., Nagathihalli Lokesh, B., Fritsch, T., Bruno, G., Mechtcherine, V., Maas, H.-G. (2025):

  Crack analysis in an in-situ micro-tomography tension test of a carbon-reinforced specimen. Concrete structures: extend lifetime, limit impacts - Proceedings of fib Symposium 16-18 June 2025 in Antibes, France. Briffaut, M.; Torrenti, J. M. (Eds.).  1413-1422.

Publications 2024

• Vakaliuk, I., Scheerer, S., Liebold, F., Wagner, F., Kruppa, H., Vollpracht, A., Curbach, M. (2024):

  Properties of the High-Performance Matrix of TRC Elements Cast Under Vacuum Conditions. Transforming Construction: Advances in Fiber Reinforced Concrete: XI RILEM-fib International Symposium on Fiber Reinforced Concrete (BEFIB 2024). Mechtcherine, V., Signorini, C. & Junger, D. (Hrsg.). Cham: Springer Nature Switzerland, 786-793.

• Hardner, M., Liebold, F., Wagner, F., Maas, H.-G. (2024):
  Investigations into the Geometric Calibration and Systematic Effects of a Micro-CT System. Sensors, 24(16), 5139, https://doi.org/10.3390/s24165139.

Publications 2023

• Wagner, F.; Maas, H.-G. (2023):
  A Comparative Study of Deep Architectures for Voxel Segmentation in Volume Image. ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, XLVIII-1/W2-2023, 1667–1676,
  https://doi.org/10.5194/isprs-archives-XLVIII-1-W2-2023-1667-2023.

• Liebold, F.; Wagner, F.; Giese, J.; Grzesiak, S.; de Sousa, C.; Beckmann, B.; Pahn, M.; Marx, S.; Curbach, M.; Maas, H.-G. (2023):
  Damage Analysis and Quality Control of Carbon-Reinforced Concrete Beams Based on In Situ Computed Tomography Tests. Buildings 2023, 13(10), 2669,
  https://doi.org/10.3390/buildings13102669.

• Giese, J; Herbers, M; Liebold, F; Wagner, F; Grzesiak, S; de Sousa, C; Pahn, M; Maas, H.-G.; Marx, S; Curbach, M; Beckmann, B (2023):
  Investigation of the Crack Behavior of CRC Using 4D Computed Tomography, Photogrammetry, and Fiber Optic Sensing. Buildings 2023, 13(10), 2595,
  https://doi.org/10.3390/buildings13102595.

• Liebold, F; Mader, D; Sardemann, H; Eltner, A; Maas, H.-G (2023):
  A Bi-Radial Model for Lens Distortion Correction of Low-Cost UAV Cameras. Remote Sens. 2023, 15(22), 5283,
  https://doi.org/10.3390/rs15225283.

• Wagner, F.; Mester, L., Klinkel, S.; Maas, H.-G. (2023):
  Analysis of Thin Carbon Reinforced Concrete Structures through Microtomography and Machine Learning. Buildings 2023, 13(9), 2399,
  https://doi.org/10.3390/buildings13092399.

• Mester, L; Klempt, V.; Wagner, F.; Scheerer, S.; Klarmann, S.; Vakaliuk, I.; Curbach, M.; Maas, H.-G.; Loehnert, S.; Klinkel, S. (2023):
  A Comparison of Multiscale Methods for the Modelling of Carbon-Reinforced Concrete Structures. Building for the Future: Durable, Sustainable, Resilient. fib Symposium 2023. Lecture Notes in Civil Engineering, vol 350. Springer, 1418–1427,
  https://doi.org/10.1007/978-3-031-32511-3_145.
• Liebold, F., Bergmann, S., Bosbach, S., Adam, V., Marx, S., Claßen, M., Hegger, J., Maas, H.-G. (2023):
  Photogrammetric Image Sequence Analysis for Deformation Measurement and Crack Detection Applied to a Shear Test on a Carbon Reinforced Concrete Member. Proceedings of 19th fib Symposium 5-7 June 2023 in Istanbul, Turkey,  Lecture Notes in Civil Engineering, vol 349, 1273–1282, https://doi.org/10.1007/978-3-031-32511-3_130.

• Wagner, F., Eltner, A., Maas, H.-G. (2023):

  River water segmentation in surveillance camera images: A comparative study of offline and online augmentation using 32 CNNs. International Journal of Applied Earth Observation and Geoinformation, 119, 103305, https://doi.org/10.1016/j.jag.2023.103305.

• Curosu, V., Kikis, G., Krüger, C., Liebold, F., Macek, D., Mester, L., Platen, J., Ritzert, S., Stüttgen, S., Kaliske, M., Klinkel, S., Löhnert, S., Maas, H.-G., Reese, S., Robertz, D. (2023):
  Ansätze für numerische Methoden zur Inspiration, Analyse und Bewertung neuartiger Carbonbetonstrukturen. Bauingenieur, 98(11), 368-377, https://doi.org/10.37544/0005-6650-2023-11-56.

Publications 2022

• Liebold, F., Maas, H.-G. (2022):
  An approach to subpixel accuracy widening crack width determination in image sequences. ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, XLVIII-2/W2-2022, 61–68, https://doi.org/10.5194/isprs-archives-XLVIII-2-W2-2022-61-2022.
• Mester, L., Wagner, F., Liebold, F., Klarmann, S., Maas, H.-G., Klinkel, S. (2022):
  Image-based modelling and analysis of carbon-fibre reinforced concrete shell structures. Proceedings for the 6th fib International Congress: Concrete Innovation for Sustainability. 1. ed. Oslo, Vol. 6, 1631-1640.
• Liebold, F., Maas, H.-G. (2022):
  Computational Optimization of the 3D Least-Squares Matching Algorithm by Direct Calculation of Normal Equations. Tomography 8(2), 760-777, https://doi.org/10.3390/tomography8020063.
• Liebold, F., Maas, H.-G. (2022):
  3D-Deformationsanalyse und Rissdetektion in multitemporalen Voxeldaten von Röntgentomographen. Dreiländertagung der DGPF, der OVG und der SGPF in Dresden – Publikationen der DGPF,  Band 30, 105–116, https://doi.org/10.24407/KXP:1796026123.

Publications 2021

• Liebold, F., Lorenzoni, R., Curosu, I., Léonard, F., Mechtcherine, V., Paciornik, S., Maas, H.-G. (2021):
  3D Least Squares Matching Applied to Micro-Tomography Data. ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, XLIII-B2-2021, 533–539, https://doi.org/10.5194/isprs-archives-XLIII-B2-2021-533-2021.