Analysing Strain and Pore Evolution in Cement Mortar Using X-ray Tomography
(2026) In ISRN LUTFD2/TFHF-26/5272-SE(1-72) FHLM01 20261Solid Mechanics
Department of Construction Sciences
- Abstract
- Freeze-thaw cycling is a major durability issue in cement-based materials, as water within its pores can freeze, expand and generate internal stresses that contribute to cracking and material degradation. Understanding how pores, water distribution and deformation evolve during repeated temperature cycles is therefore important for improving the durability of these materials. This thesis investigates freeze-thaw behaviour in a cement mortar specimen using X-ray tomography data acquired during repeated freezing and thawing. Although the experiment included both X-ray and neutron tomography, the scope of this work focuses only on the X-ray data.
A Python-based workflow was developed to analyse the tomographic datasets. The workflow... (More) - Freeze-thaw cycling is a major durability issue in cement-based materials, as water within its pores can freeze, expand and generate internal stresses that contribute to cracking and material degradation. Understanding how pores, water distribution and deformation evolve during repeated temperature cycles is therefore important for improving the durability of these materials. This thesis investigates freeze-thaw behaviour in a cement mortar specimen using X-ray tomography data acquired during repeated freezing and thawing. Although the experiment included both X-ray and neutron tomography, the scope of this work focuses only on the X-ray data.
A Python-based workflow was developed to analyse the tomographic datasets. The workflow involves image preprocessing, global rigid registration, Digital Volume Correlation (DVC), strain analysis and joint histogram-based pore segmentation. The DVC and strain analysis were performed using SPAM, while segmentation was performed using evoSegment. The pipelines were designed to be reusable for future analysis at the European Spallation Source (ESS).
The initial global registration study showed that using a representative image range, excluding regions affected by artefacts, improved both alignment quality and computational efficiency. The DVC parameter study identified a half-window size of 20 pixels, node spacing of 20 pixels and search range of 20 pixels as a good compromise between convergence, resolution and computational cost. The strain analysis showed that DVC can identify regions of deformation and cracking, especially near the specimen perimeter. However, the absolute strain magnitudes should be interpreted with caution due to edge effects caused by the strain algorithm, cracking, fragment movement and image noise.
The joint histogram-based pore segmentation showed differences between inner, intermediate and outer pores. Outer pores were generally more affected by freeze-thaw cycling, showing water loss and nearby crack formation. In contrast, inner and intermediate pores were mainly air-filled and showed no visible cracking, with water appearing to redistribute internally rather than leaving the pore.
Overall, the workflow provides a useful basis for analysing deformation, cracking and pore evolution during freeze-thaw cycling. Future work should focus on validating the results with neutron data, improving boundary and registration handling, and analysing a larger number of pores and specimens to quantify water redistribution and damage development more systematically. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/student-papers/record/9240958
- author
- Peric, Tanja LU
- supervisor
- organization
- alternative title
- Röntgentomografisk undersökning av porer och töjning i cementbruk
- course
- FHLM01 20261
- year
- 2026
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- cement mortar, freeze-thaw cycling, X-ray computed tomography, digital volume correlation (DVC), strain analysis, pore segmentation, image registration, joint histogram segmentation, european spallation source
- publication/series
- ISRN LUTFD2/TFHF-26/5272-SE(1-72)
- report number
- TFHF-5272
- language
- English
- id
- 9240958
- date added to LUP
- 2026-06-25 14:17:16
- date last changed
- 2026-06-25 14:17:16
@misc{9240958,
abstract = {{Freeze-thaw cycling is a major durability issue in cement-based materials, as water within its pores can freeze, expand and generate internal stresses that contribute to cracking and material degradation. Understanding how pores, water distribution and deformation evolve during repeated temperature cycles is therefore important for improving the durability of these materials. This thesis investigates freeze-thaw behaviour in a cement mortar specimen using X-ray tomography data acquired during repeated freezing and thawing. Although the experiment included both X-ray and neutron tomography, the scope of this work focuses only on the X-ray data.
A Python-based workflow was developed to analyse the tomographic datasets. The workflow involves image preprocessing, global rigid registration, Digital Volume Correlation (DVC), strain analysis and joint histogram-based pore segmentation. The DVC and strain analysis were performed using SPAM, while segmentation was performed using evoSegment. The pipelines were designed to be reusable for future analysis at the European Spallation Source (ESS).
The initial global registration study showed that using a representative image range, excluding regions affected by artefacts, improved both alignment quality and computational efficiency. The DVC parameter study identified a half-window size of 20 pixels, node spacing of 20 pixels and search range of 20 pixels as a good compromise between convergence, resolution and computational cost. The strain analysis showed that DVC can identify regions of deformation and cracking, especially near the specimen perimeter. However, the absolute strain magnitudes should be interpreted with caution due to edge effects caused by the strain algorithm, cracking, fragment movement and image noise.
The joint histogram-based pore segmentation showed differences between inner, intermediate and outer pores. Outer pores were generally more affected by freeze-thaw cycling, showing water loss and nearby crack formation. In contrast, inner and intermediate pores were mainly air-filled and showed no visible cracking, with water appearing to redistribute internally rather than leaving the pore.
Overall, the workflow provides a useful basis for analysing deformation, cracking and pore evolution during freeze-thaw cycling. Future work should focus on validating the results with neutron data, improving boundary and registration handling, and analysing a larger number of pores and specimens to quantify water redistribution and damage development more systematically.}},
author = {{Peric, Tanja}},
language = {{eng}},
note = {{Student Paper}},
series = {{ISRN LUTFD2/TFHF-26/5272-SE(1-72)}},
title = {{Analysing Strain and Pore Evolution in Cement Mortar Using X-ray Tomography}},
year = {{2026}},
}