In-situ X-ray differential micro-tomography for investigation of water-weakening in quasi-brittle materials subjected to four-point bending

0523139 - ÚTAM 2021 RIV CH eng J - Journal Article
Koudelka_ml., Petr - Fíla, Tomáš - Rada, Václav - Zlámal, Petr - Šleichrt, Jan - Vopálenský, Michal - Kumpová, Ivana - Beneš, Pavel - Vavřík, Daniel - Vavro, Leona - Vavro, Martin - Drdácký, Miloš - Kytýř, Daniel
In-situ X-ray differential micro-tomography for investigation of water-weakening in quasi-brittle materials subjected to four-point bending.
Materials. Roč. 13, č. 6 (2020), č. článku 1405. E-ISSN 1996-1944
R&D Projects: GA MŠMT(CZ) EF16_019/0000766
Institutional support: RVO:68378297 ; RVO:68145535
Keywords : fracture propagation * in-situ X-ray 4D micro-CT * differential tomography * digital volume correlation * quasi-brittle materials * water-weakening * four-point bending
OECD category: Materials engineering; Environmental and geological engineering, geotechnics (UGN-S)
Impact factor: 3.623, year: 2020
Method of publishing: Open access
https://doi.org/10.3390/ma13061405

Several methods, including X-ray radiography, have been developed for the investigation of the characteristics of water-saturated quasi-brittle materials. Here, the water content is one of the most important factors influencing their strength and fracture properties, in particular, as regards to porous building materials. However, the research concentrated on the three-dimensional fracture propagation characteristics is still significantly limited due to the problems encountered with the instrumentation requirements and the size e_ect. In this paper, we study the influence of the water content in a natural quasi-brittle material on its mechanical characteristics and fracture development during in-situ four-point bending by employing high-resolution X-ray di_erential micro-tomography. The cylindrical samples with a chevron notch were loaded using an in-house designed four-point bending loading device with the vertical orientation of the sample. The in-house designed modular micro-CT scanner was used for the visualisation of the specimen’s behaviour during the loading experiments. Several tomographic scans were performed throughout the force-displacement diagrams of the samples. The reconstructed 3D images were processed using an in-house developed di_erential tomography and digital volume correlation algorithms. The apparent reduction in the ultimate strength was observed due to the moisture content. The crack growth process in the water-saturated specimens was identified to be di_erent in comparison with the dry specimens
Permanent Link: http://hdl.handle.net/11104/0307537