Partner: Tomas Dvorak

Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)

Recent publications
1.Żołek N., Ranachowski Z., Ranachowski P., Jóźwiak-Niedźwiedzka D., Kúdela Jr S., Dvorak T., Statistical assessment of the microstructure of barite aggregate from different deposits using x-ray microtomography and optical microscopy, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.1515/amm-2017-0104, Vol.62, No.2, pp.697-702, 2017
Abstract:

Two different barite ore (barium sulfate BaSO4) specimens from different localizations were tested and described in this paper. Analysis of the microstructure was performed on polished sections, and on thin sections using X-ray microtomography (micro-CT), and optical microscopy (MO). Microtomography allowed obtaining three-dimensional images of the barite aggregate specimens. In the tomograms, the spatial distribution of the other polluting phases, empty space as well as cracks, pores, and voids – that exceeded ten micrometers of diameter-were possible to visualize. Also, the micro-CT allowed distinguishing between minerals of different density, like SiO2 and BaSO4. Images obtained and analyzed on thin sections with various methods using the optical microscopy in transmitted light delivered additional information on the aggregate microstructure, i.e. allow for estimation of the different kinds of inclusions (like the different density of the minerals) in the investigated specimens. Above methods, which were used in the tests, completed each another in order to supply a set of information on inclusions’ distribution and to present the important differences of the barite aggregate specimens microstructure.

Keywords:

barite ore, barite aggregate, microstructure, optical microscopy, thin sections analysis, X-ray tomography

Affiliations:
Żołek N.-IPPT PAN
Ranachowski Z.-IPPT PAN
Ranachowski P.-IPPT PAN
Jóźwiak-Niedźwiedzka D.-IPPT PAN
Kúdela Jr S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Dvorak T.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
2.Schabowicz K., Ranachowski Z., Jóźwiak-Niedźwiedzka D., Radzik Ł., Kúdela Jr S., Dvorak T., Application of X-ray microtomography to quality assessment of fibre cement boards, CONSTRUCTION AND BUILDING MATERIALS, ISSN: 0950-0618, DOI: 10.1016/j.conbuildmat.2016.02.035, Vol.110, pp.182-188, 2016
Abstract:

In this paper a method of X-ray microtomography (micro-CT) was employed for a direct insight into a microstructure of fibre cement boards of different quality. Four specimens were subjects of examination. Two parameters were determined to characterize the level of compaction of fibres in concrete matrix: mean-square displacement of migrating virtual particles after 500,000 of time steps and a diffusive tortuosity. The results of the investigation had revealed that fibre cement boards differing in density produce different images after processing with micro-CT method. The effect of microstructure tightening due to saturation using dying agent was also detectable.

Keywords:

Fibre cement boards, Delamination of fibres, Computational modelling, X-ray microtomography

Affiliations:
Schabowicz K.-other affiliation
Ranachowski Z.-IPPT PAN
Jóźwiak-Niedźwiedzka D.-IPPT PAN
Radzik Ł.-other affiliation
Kúdela Jr S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Dvorak T.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
3.Ranachowski Z., Jóźwiak-Niedźwiedzka D., Ranachowski P., Dąbrowski M., Kúdela Jr S., Dvorak T., The determination of diffusive tortuosity in concrete specimens using X-ray microtomography, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.1515/amm-2015-0140, Vol.60, No.2, pp.1115-1119, 2015
Abstract:

The paper presents a method of pore connectivity analysis applied to specimens of cement based composites differing in water to cement ratio. The method employed X-ray microtomography (micro-CT). Microtomography supplied digitized three-dimensional radiographs of small concrete specimens. The data derived from the radiographs were applied as an input into the application based on the algorithm called ‘random walk simulation’. As the result a parameter called diffusive tortuosity was established and compared with estimated porosity of examined specimens.

Artykuł prezentuje metodę wyznaczania parametru charakteryzującego intensywność połączeń mikroporów w zastosowaniu do próbek kompozytów z matrycą cementową, różniących się stosunkiem wodnocementowym. Metoda bazuje na wynikach badań z zastosowaniem mikrotomografii rentgenowskiej. Analizowano zdigitizowane zestawy danych, opisujące trójwymiarową reprezentację mikrostruktury niewielkich próbek wykonanych z betonu. Przygotowane w ten sposób skany mikrostruktury zastosowano jako dane wejściowe wprowadzone do oprogramowania wykorzystujacego algorytm ‘przypadkowo migrujących cząstek wirtualnych’. W ten sposób wyznaczono parametr mikrostruktury znany jako krętość dyfuzyjna. Parametr ten porównano z porowatością obserwowaną wyznaczoną dla zbadanych próbek przy wykorzystaniu analizy jasności voxeli w analizowanych próbkach.

Keywords:

X-ray tomography, concrete microstructure, diffusive tortuosity

Affiliations:
Ranachowski Z.-IPPT PAN
Jóźwiak-Niedźwiedzka D.-IPPT PAN
Ranachowski P.-IPPT PAN
Dąbrowski M.-IPPT PAN
Kúdela Jr S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Dvorak T.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
4.Ranachowski Z., Jóźwiak-Niedźwiedzka D., Ranachowski P., Rejmund F., Dąbrowski M., Kúdela Jr S., Dvorak T., Application of X-ray microtomography and optical microscopy to determine the microstructure of concrete penetrated by carbon dioxide, ARCHIVES OF METALLURGY AND MATERIALS, ISSN: 1733-3490, DOI: 10.2478/amm-2014-0245, Vol.59, No.4, pp.1451-1457, 2014
Abstract:

In the paper two advanced methods for testing cement based composites are described and compared. These are X-ray microtomography and optical microscopy. Microtomography supplies three-dimensional images of small concrete specimens. In the tomograms all cracks, pores and other voids and inclusions, that exceed a few micrometers, are shown. Such visualisation can become a valuable tool for analysis of the basic material properties. Images obtained on thin sections and analysed with various methods on optical microscopes supply additional information on material microstructure that cannot be obtained in tomograms. For example it is relatively easy to determine zone penetrated by CO2 ingress. These two methods, presented on examples of tests, complete each another in order to supply a set of information on composition and defects of tested composite materials.

Keywords:

cement matrix composites, concrete deterioration, X-ray tomography, microscopic analysis, concrete microstructure

Affiliations:
Ranachowski Z.-IPPT PAN
Jóźwiak-Niedźwiedzka D.-IPPT PAN
Ranachowski P.-IPPT PAN
Rejmund F.-IPPT PAN
Dąbrowski M.-IPPT PAN
Kúdela Jr S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Dvorak T.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)

Conference papers
1.Ranachowski Z., Jóźwiak-Niedźwiedzka D., Ranachowski P., Dąbrowski M., Kúdela Jr S., Dvorak T., Analysis of pore distribution and connectivity in concrete using X-ray microtomography, BMC-11, 11th International Symposium on Brittle Matrix Composites, 2015-09-28/09-30, Warsaw (PL), pp.203-212, 2015
Abstract:

In the paper a method of X-ray microtomography (micro-CT) was employed for a direct insight into a microstructure of concrete with a practical resolution of approx. 10 micrometers3. Two sets of specimens were subjects of examination. The spatial concentration of air pores was investigated in three concretes differing in the amount of the supplement of high calcium fly ash (HCFA). The parameter of pore connectivity called diffusive tortuosity was determined in three other concretes made of the same ingredients but differing in water to cement ratio. The quantitative results obtained with application of described procedures are applicable in material characterization.

Keywords:

X-ray microtomography, concrete, microstructure

Affiliations:
Ranachowski Z.-IPPT PAN
Jóźwiak-Niedźwiedzka D.-IPPT PAN
Ranachowski P.-IPPT PAN
Dąbrowski M.-IPPT PAN
Kúdela Jr S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Dvorak T.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)

Conference abstracts
1.Ranachowski Z., Jóźwiak-Niedźwiedzka D., Ranachowski P., Pawełek A., Kúdela Jr S., Dvorak T., The analysis of pore distribution and pore connectivity in concrete samples using x-ray microtomography, SolMech 2014, 39th Solid Mechanics Conference, 2014-09-01/09-05, Zakopane (PL), pp.199-200, 2014
Abstract:

The durability of concrete in outdoor structures is closely related to its resistance against the aggressive gaseous actions coming from the environment and including influence of oxygen, nitrogen, carbon dioxide. The pore system and its interconnectivity in the concrete matrix directly influence the possibility of penetration of various aggressive gaseous media into concrete structure. The X-ray microtomography (micro-CT) is a modern, non-invasive technique enabling for determination of existing pores in the microstructure of concrete matrix. In the paper the results of investigation of two different concretes by the application of micro-CT method to micro-cores are presented. The quantitative information on the parameters of the analysed microstructure can improve the methods of material characterization available up to now.

Keywords:

X-ray microtomography, concrete, microstructure

Affiliations:
Ranachowski Z.-IPPT PAN
Jóźwiak-Niedźwiedzka D.-IPPT PAN
Ranachowski P.-IPPT PAN
Pawełek A.-other affiliation
Kúdela Jr S.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)
Dvorak T.-Institute of Materials and Machine Mechanics, Slovak Academy of Sciences (SK)