Automatizovaný systém řízení laboratoře zemědělského sila

Prezenční výpůjčkaVŠB - Technická univerzita Ostrava. Fakulta elektrotechniky a informatiky. Katedra (455) měřící a řídící technik

MINERALOGY OF MEDIEVAL SLAGS FROM BOHUTÍN AS A TOOL FOR DETERMINATION OF HISTORICAL Pb - Ag SMELTING TECHNOLOGY

Institute of Geochemistry, Mineralogy and Mineral ResourcesÚstav geochemie, mineralogie a nerostných zdrojůFaculty of SciencePřírodovědecká fakult

MINERALOGY OF MEDIEVAL SLAGS FROM BOHUTÍN AS A TOOL FOR DETERMINATION OF HISTORICAL Pb - Ag SMELTING TECHNOLOGY

Ústav geochemie, mineralogie a nerostných zdrojůInstitute of Geochemistry, Mineralogy and Mineral ResourcesFaculty of SciencePřírodovědecká fakult

Suitability of technical materials for machinery subsoilers for soil tillage

Agricultural soil processing belongs to the basic elements in the process of crop production. Currently classic tillage method is decreasing and the only trend has stated as a shallow plowing. Suitable post harvest soil tillage greatly affects yields in the next cycle. The aim of the study is the analysis of abrasive wear of selected construction materials and their subsequent use for DXRV-HD cultivator. The performed tests are focused on monitoring the mechanical properties of the materials and their use for variable cutting tip of cultivator body. Tested materials are divided into four categories. These materials include tool steel (19436), carbon steel (12050), cast iron with globular graphite and welding material supplied as a functional complex on low carbon steel by the Abraweld company. These materials are tested together with the original part of share cultivator. The present experiment is focused on metallorgraphic, mechanical and abrasive analysis. Structural component of the material is identified by metallographic photos and then compared with the impact strength tested on Charpy hammer. Followed the abrasion resistance according to CSN 01 5084 and the total evaluation of the tested samples are done

Characterization of Cebama low-pH reference concrete and assessment of its alteration with representative waters in radioactive waste repositories

Concretes, mortars and grouts are used for structural and isolation purposes in radioactive and nuclear waste repositories. For example, concrete is used for deposition tunnel end plugs, engineered barriers, mortars for rock bolting and injection grouts for fissure sealing. Despite of the materials anticipated functionality, it is extremely important to understand the long-term material behaviour in repository environments. A reference concrete and mortar for the Cebama project based on a cement, silica and blast furnace slag ternary blend were designed and characterized in different laboratories with multiple experimental methods (XRD, XAS at the Fe and Cl K-edges, SEM-EDX, 29Si and 27Al MAS-NMR, TG-DSC, MIP and Kerosene porosimetry) and techniques (punch strength tests). The reference concrete enabled comparison of results from different institutes and experimental techniques, unifying the individual results to more comprehensive body. The Cebama reference concrete and mortar were designed to have high durability and compatible formulation with respect to an engineered barrier system in clay or crystalline host-rocks, having pore solution pH significantly lower than traditional concretes. This work presents main results regarding their characterization and alteration in contact with representative waters present in radioactive waste repositories. Pore solution pH of the matured reference concrete was 11.4–11.6. The main hydrated phases were C–S–H and C-A-S-H gels with a Ca:Si ratio between 0.5 and 0.7 and an Al:Si ratio of 0.05. Minor phases were ettringite and hydrotalcite. Iron(III) could be in the C–S–H phases and no Cl-bearing solid phases were identified. Connected porosity and pore size distribution was characterized by MIP observing that, as expected, the size of the pores in the hydrated cement phases varies from the micro-to the nanoscale. Connected porosity of both materials were low. Compressive strength of the concrete was 115 MPa, corresponding to traditional high-performance concrete. Degradation of these materials in contact with different waters mainly produce their decalcification and enrichment in Mg for waters containing high amount of this element, like the clay waters.•The performance of “low-pH” mix designs containing slag exceeds the performance of traditional Portland cement concretes.•That slag is able to replace fly ash when producing ”low-pH” mixtures, if needed due to material supply or quality problems.•Eight experimental techniques have provided mechanical, hydraulic and geochemical properties of new designed materials.•Micro-mortar in contact with clay and bentonite waters, shows a Mg enrichment and calcium depletion at the reaction front

Characterization of Cebama low-pH reference concrete and assessment of its alteration with representative waters in radioactive waste repositories

Concretes, mortars and grouts are used for structural and isolation purposes in radioactive and nuclear wasterepositories. For example, concrete is used for deposition tunnel end plugs, engineered barriers, mortars for rockbolting and injection grouts for fissure sealing. Despite of the materials anticipated functionality, it is extremelyimportant to understand the long-term material behaviour in repository environments. A reference concrete andmortar for the Cebama project based on a cement, silica and blast furnace slag ternary blend were designed andcharacterized in different laboratories with multiple experimental methods (XRD, XAS at the Fe and Cl K-edges,SEM-EDX, 29Si and 27Al MAS-NMR, TG-DSC, MIP and Kerosene porosimetry) and techniques (punch strengthtests). The reference concrete enabled comparison of results from different institutes and experimental techniques,unifying the individual results to more comprehensive body. The Cebama reference concrete and mortarwere designed to have high durability and compatible formulation with respect to an engineered barrier systemin clay or crystalline host-rocks, having pore solution pH significantly lower than traditional concretes. This workpresents main results regarding their characterization and alteration in contact with representative waterspresent in radioactive waste repositories. Pore solution pH of the matured reference concrete was 11.4–11.6. Themain hydrated phases were C–S–H and C-A-S-H gels with a Ca:Si ratio between 0.5 and 0.7 and an Al:Si ratio of0.05. Minor phases were ettringite and hydrotalcite. Iron(III) could be in the C–S–H phases and no Cl-bearingsolid phases were identified. Connected porosity and pore size distribution was characterized by MIPobserving that, as expected, the size of the pores in the hydrated cement phases varies from the micro-to thenanoscale. Connected porosity of both materials were low. Compressive strength of the concrete was 115 MPa,corresponding to traditional high-performance concrete. Degradation of these materials in contact with differentwaters mainly produce their decalcification and enrichment in Mg for waters containing high amount of thiselement, like the clay waters

Characterization of Cebama low-pH reference concrete and assessment of its alteration with representative waters in radioactive waste repositories

Concretes, mortars and grouts are used for structural and isolation purposes in radioactive and nuclear waste repositories. For example, concrete is used for deposition tunnel end plugs, engineered barriers, mortars for rock bolting and injection grouts for fissure sealing. Despite of the materials anticipated functionality, it is extremely important to understand the long-term material behaviour in repository environments. A reference concrete and mortar for the Cebama project based on a cement, silica and blast furnace slag ternary blend were designed and characterized in different laboratories with multiple experimental methods (XRD, XAS at the Fe and Cl K-edges, SEM-EDX, 29Si and 27Al MAS-NMR, TG-DSC, MIP and Kerosene porosimetry) and techniques (punch strength tests). The reference concrete enabled comparison of results from different institutes and experimental techniques, unifying the individual results to more comprehensive body. The Cebama reference concrete and mortar were designed to have high durability and compatible formulation with respect to an engineered barrier system in clay or crystalline host-rocks, having pore solution pH significantly lower than traditional concretes. This work presents main results regarding their characterization and alteration in contact with representative waters present in radioactive waste repositories. Pore solution pH of the matured reference concrete was 11.4–11.6. The main hydrated phases were C–S–H and C-A-S-H gels with a Ca:Si ratio between 0.5 and 0.7 and an Al:Si ratio of 0.05. Minor phases were ettringite and hydrotalcite. Iron(III) could be in the C–S–H phases and no Cl-bearing solid phases were identified. Connected porosity and pore size distribution was characterized by MIP observing that, as expected, the size of the pores in the hydrated cement phases varies from the micro-to the nanoscale. Connected porosity of both materials were low. Compressive strength of the concrete was 115 MPa, corresponding to traditional high-performance concrete. Degradation of these materials in contact with different waters mainly produce their decalcification and enrichment in Mg for waters containing high amount of this element, like the clay waters.</p

Cebama reference mix design for low-pH concrete and paste, preliminary characterisation

Trabajo presentado al Second Workshop of the HORIZON 2020 CEBAMA Project, celebrado en Espoo (Finlandia), del 16 al 18 de mayo de 2017.A reference low-pH concrete and paste mix were manufactured within the Cebama-project. Reference mixtures were casted at VTT in March 2016 and were distributed among some of the Cebama partners. Reference mix designs will be used by different partners as a common material to study their behaviour in contact with waters of different composition and interaction with radionuclides. Additionally, these materials will be used for model calibration. This article provides a summary of the characterization methods used by different partners and gives an overview of the experiments which will be made in the future with the reference materials.The research leading to these results has received funding from the European Union's Horizon 2020 Reasearch and Training Programme of the European Atomic Energy Community (EURATOM) (H2020-NFRP-2014/2015) under grant agreement n° 662147 (CEBAMA)