Partner: Krzysztof Schabowicz |
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Recent publications
1. | Ranachowski Z., Ranachowski P., Dębowski T., Brodecki A., Kopeć M., Roskosz M.♦, Fryczowski K.♦, Szymków M.♦, Krawczyk E.♦, Schabowicz K.♦, Mechanical and non-destructive testing of plasterboards subjected to a hydration process, Materials, ISSN: 1996-1944, DOI: 10.3390/ma13102405, Vol.13, No.10, pp.2405-1-18, 2020 Abstract: The aim of this study was to investigate the effect of plasterboards' humidity absorption on their performance. Specimens' hydration procedure consisted of consecutive immersing in water and subsequent drying at room temperature. Such a procedure was performed to increase the content of moisture within the material volume. The microstructural observations of five different plasterboard types were performed through optical and scanning electron microscopy. The deterioration of their properties was evaluated by using a three-point bending test and a subsequent ultrasonic (ultrasound testing (UT)) longitudinal wave velocity measurement. Depending on the material porosity, a loss of UT wave velocity from 6% to 35% and a considerable decrease in material strength from 70% to 80% were observed. Four types of approximated formulae were proposed to describe the dependence of UT wave velocity on board moisture content. It was found that the proposed UT method could be successfully used for the on-site monitoring of plasterboards' hydration processes. Keywords:plasterboards, moisture content, hydration processes, mechanical properties, ultrasound measurements Affiliations:
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2. | Ranachowski Z., Ranachowski P., Dębowski T., Gorzelańczyk T.♦, Schabowicz K.♦, Investigation of structural degradation of fiber cement boards due to thermal impact, Materials, ISSN: 1996-1944, DOI: 10.3390/ma12060944, Vol.12, No.6, pp.944-1-14, 2019 Abstract: The aim of the present study was to investigate the degradation of the microstructure and mechanical properties of fiber cement board (FCB), which was exposed to environmental hazards, resulting in thermal impact on the microstructure of the board. The process of structural degradation was conducted under laboratory conditions by storing the FCB specimens in a dry, electric oven for 3 h at a temperature of 230 °C. Five sets of specimens, that differed in cement and fiber content, were tested. Due to the applied heating procedure, the process of carbonization and resulting embrittlement of the fibers was observed. The fiber reinforcement morphology and the mechanical properties of the investigated compositions were identified both before, and after, their carbonization. Visual light and scanning electron microscopy, X-ray micro tomography, flexural strength, and work of flexural test Wf measurements were used. A dedicated instrumentation set was prepared to determine the ultrasound testing (UT) longitudinal wave velocity cL in all tested sets of specimens. The UT wave velocity cL loss was observed in all cases of thermal treatment; however, that loss varied from 2% to 20%, depending on the FCB composition. The results obtained suggest a possible application of the UT method for an on-site assessment of the degradation processes occurring in fiber cement boards. Keywords:cement-based composites, fiber cement boards, durability, ultrasound measurements Affiliations:
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3. | Schabowicz K.♦, Jóźwiak-Niedźwiedzka D., Ranachowski Z., Kúdela Jr S.♦, Dvorák T.♦, Microstructural characterization of cellulose fibres in reinforced cement boards, ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING, ISSN: 1644-9665, DOI: 10.1016/j.acme.2018.01.018, Vol.18, No.4, pp.1068-1078, 2018 Abstract: The microscopic analysis of the different cellulose fibre cement composites is presented. The observations of the fibres in optical microscope in transmitted light and in scanning electron microscope are described. The micro computed tomography (micro-CT) and SEM were used to determine the distribution of the fibres in the matrix. The investigated fibre cement boards were produced by extrusion process and panels were cured in natural conditions. The main goal of the research was application of different microscopic methods to analyze the fibres distribution as a result of a different methods of their production. Micro-CT was used for 3D visualization of fibres distribution in three different fibre cement boards. It was possible to determine the average diameter of the fibres and their concentration using the high-resolution mode of micro-CT scanning procedure. Finally, a procedure which can be applied as a useful tool for analysis of the different procedures used in production of fibre cement boards is described. This procedure can be successfully used in the quality control system of cellulose fibre distribution in cement composites Keywords:Cellulose fibre reinforced cement boards, Microstructure, Fibre distribution, X-ray microtomography, SEM-EDS analysis Affiliations:
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4. | Ranachowski Z., Schabowicz K.♦, Gorzelańczyk T.♦, Kúdela Jr S.♦, Dvorák T.♦, Visualization of Fibers and Voids Inside Industrial Fiber Concrete Boards, Material Science & Engineering International Journal, ISSN: 2574-9927, DOI: 10.15406/mseij.2017.01.00022, Vol.1, No.4, pp.1-4, 2018 Abstract: Fiber cement boards (FCB) microstructure and methods of fabrication are described. The method of X-ray microtomography in application for investigating of FCB microstructure is presented. The cellulose fibers constituting the remarkable reinforcement of the FCB are colorless and too small to be seen applying the standard optical methods. The X-ray microtomography method however enabled the authors to realize three goals within the investigation of the properties of FCB. The length and shape of the fibers could be assessed on specimens' cross-sections. Applying the pseudo 3D visualization it was possible to visualize the cracked regions inside the specimen volume. The case of non-uniform fibers distribution in respect to the board thickness which was impossible to recognize applying the standard visual inspection, was also performed by merging the multiple cross-section images into a single graph Affiliations:
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5. | Ranachowski Z., Schabowicz K.♦, The contribution of fiber reinforcement system to the overall toughness of cellulose fiber concrete panels, CONSTRUCTION AND BUILDING MATERIALS, ISSN: 0950-0618, DOI: 10.1016/j.conbuildmat.2017.09.067, Vol.156, pp.1028-1034, 2017 Abstract: The paper concerns the role of cellulose reinforcements in overall mechanical toughness of fiber concrete panels applied as facade building material. The results of mechanical tests performed on specimens in as delivered state as well as on specimens which underwent the procedure of destruction of internal fiber network structure due to pyrolysis are presented. The results of mechanical tests let the authors to calculate the work of fracture for six different mechanical conditions. Moreover the analysis of registered Acoustic Emission (AE) signal had revealed that the investigated process of destruction begins with the brittle crack generation and growth while major damages of reinforcement system appears in later phase of the process. Keywords:Fiber cement panels, Cellulose fibers, Brittle crack, Acoustic Emission Affiliations:
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6. | Schabowicz K.♦, Ranachowski Z., Jóźwiak-Niedźwiedzka D., Radzik Ł.♦, Kúdela Jr S.♦, Dvorák 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:
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7. | Dębowski T., Lewandowski M., Mackiewicz S., Ranachowski Z., Schabowicz K.♦, Badania ultradźwiękowe płyt włóknisto-cementowych, PRZEGLĄD SPAWALNICTWA, ISSN: 0033-2364, Vol.88, No.10, pp.69-71, 2016 Abstract: W artykule przedstawiona została możliwość lokalizacji delaminacji w płycie włóknisto-cementowej za pomocą specjalnie do tego celu skonstruowanego urządzenia wykorzystującego metodę ultradźwiękową i fale podłużne. Przeprowadzono badania na trzech rodzajach płyt. Stwierdzono, że proponowana metoda diagnostyczna umożliwia wykrywanie lokalnych nieciągłości, np. obszarów o obniżonej zwartości, czy delaminacji w płytach włóknisto-cementowych na obszarze średnicy wiązki metodą estymacji prędkości fali ultradźwiękowej. Zaletami metody są niewielkie wymiary urządzenia i krótki czas badania Keywords:płyty włóknisto-cementowe, badania nieniszczące, ultradźwięki Affiliations:
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Conference papers
1. | Ranachowski Z., Schabowicz K.♦, Gorzelańczyk T.♦, Lewandowski M., Cacko D., Katz T., Dębowski T., Investigation of Acoustic Properties of Fibre-Cement Boards, IEEE 2018, IEEE Joint Conference - Acoustics, 2018-09-11/09-14, Ustka (PL), DOI: 10.1109/ACOUSTICS.2018.8502341, pp.275-279, 2018 Abstract: The paper describes two different techniques of ultrasound measurements performed in fibre cement boards, the material widely applied in building technology. An in-house device dedicated for fibre-cement board testing is also presented. To overcome the difficulty of determining the arrival time of the waveform of a longitudinal wave travelling across a thin and inhomogeneous body, a cross-correlation method of signal processing was proposed and applied Keywords:ultrasound, fibre-cement board, waveform cross correlation coefficient Affiliations:
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Conference abstracts
1. | Ranachowski Z., Lewandowski M., Schabowicz K.♦, Logoń D.♦, Analysis of Acoustic Emission Signal Generated in Mechanically Loaded Reinforced and Non-Reinforced Concrete Specimens, OSA 2017, LXIV Open Seminar on Acoustics, 2017-09-11/09-15, Piekary Śląskie (PL), DOI: 10.1515/aoa-2017-0059, No.42_3, pp.552, 2017 |
Patents
Filing No./Date Filing Publication | Autor(s) Title Protection Area, Applicant Name | Patent Number Date of Grant | |
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435320 2020-09-16 BUP 12/2022 2022-03-21 | Schabowicz K.♦, Ranachowski Z., Dębowski T., Szymków M.♦, Krawczyk E.♦Urządzenie do oznaczania uwodnienia gipsu w płytach gipsowo-kartonowychPL, Politechnika Wrocławska, Instytut Podstawowych Problemów Techniki PAN | 241120 WUP 31/2022 2022-08-01 | |
417777 2016-06-30 BUP 02/2017 2017-01-16 | Dębowski T., Lewandowski M., Mackiewicz S., Ranachowski Z., Hoła J.♦, Schabowicz K.♦Sposób wykrywania delaminacji w płytach włókno-cementowych i urządzenie do wykrywania delaminacji w płytach włókno-cementowychPL, Politechnika Wrocławska, Instytut Podstawowych Problemów Techniki PAN | 227043 WUP 10/2017 2017-10-31 |