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X-ray computer tomographic analysis of four concrete specimens based on steel-making slag and artificial dense aggregates
Souček, Kamil ; Georgiou, Lucie
Visualization of the internal structure, evaluation of the structure and basic analysis of porosity on four concrete test specimens were carried out. The non-destructive method of industry 3D X-ray computed tomography was used for the analysis of the test specimens. Based on the CT slices of individual the specimens of concrete, the four basic components of concrete were identified (i) cement binder, ii) fraction formed by steel-making slag, iii) fraction formed by artificial dense aggregate, iv) the last component of concrete is represented by pores). The carried out CT porosity analysis determined the average porosity of the investigated concrete at the level of 6.5 ± 1.52%.
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X-Ray CT inspection of subsurface areas of concretes exposed to fast flowing liquids
Sitek, Libor ; Hlaváček, Petr ; Souček, Kamil ; Bodnárová, L. ; Foldyna, Josef ; Zajícová, Vendula ; Berčáková, Andrea ; Foldyna, Vladimír
Concrete structures affected for a long time by flowing liquids are exposed to gradual erosion in surface layers caused by a combination of several degradation processes: abrasion, cavitation and chemical or bacterial impacts. Due to the complex phenomena and difficult-to-define initial and boundary conditions, the whole process cannot be easily simulated using the conventional computing tools. Laboratory experimental research is thus the most appropriate approach for the investigation of a suitable composition of concrete resistant to the flowing liquids. However, the methods used are often very time consuming and last even several years. High-speed water flows can be elegantly used for the acceleration of the mechanical simulation of a real situation. Several experiments on the effects of the high-speed water flows on concrete surfaces have been carried out. Using the X-Ray CT methods, subsurface structures of concretes exposed to the accelerated mechanical simulation of the erosion wear caused by fast flowing liquids were investigated and presented in the article. It has been shown that the simulation does not cause initiation of new fractures or cracks in the original concrete structure. The pure water flow mainly removes the hardened cement paste and reveals the aggregate grains. The water flow with abrasive particles disintegrates in greater depths and washes out entire aggregate grains, eventually amputates them and finally smoothens entire surface.
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Application of high speed water jet technology for concrete repair
Bodnárová, L. ; Sitek, Libor ; Foldyna, Josef ; Jarolím, T.
This article brings selected knowledge from the long-term cooperation between\nthe Brno University of Technology, the Faculty of Civil Engineering, the Institute of\nTechnology of Building Materials and Components, and the Academy of Sciences of\nthe Czech Republic, v.v.i., Institute of Geonics, Ostrava – Poruba in the field of\nthe interaction of high-speed water jets and concrete, especially with regard to\nthe use of high-speed water jet technology for the removal of surface layers of\nconcrete during repair of concrete.
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Prospects of the use of X-ray computer tomography in geomaterials and geotechnics research
Souček, Kamil ; Staš, Lubomír
The paper deals with possibilities of industry X-Ray CT utilization in geo-materials and geotechnical research. This paper was elaborated on the basis of professional literature study (Proc. of the Int. Workshop on X-ray CT for Geomaterials – soils, concrete, rocks, Geox 2003 and Proc. of the Int. Workshop on Advances in X-Ray Tomography for Geomaterials, Geox 2006) and first experiences of X-Ray CT utilization within the frame of research activities of Institute of geonics, ASCR, at Kumamoto University. There are some results from coal geocomposite failure study, visualization of geocomposite wetting (soaking) process and checking of drill core integrity after carried out overcoring stress measurements in the paper.
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