Angela D'Elia - Academia.edu (original) (raw)
Address: Taranto, Puglia, Italy
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Papers by Angela D'Elia
Polymers
This work deals with the investigation of alkaline binders obtained from binary mixtures of carbo... more This work deals with the investigation of alkaline binders obtained from binary mixtures of carbonate-rich illitic clay from deposits in southern Italy and two industrial by-products with very different total composition and calcium content, i.e., blast furnace slag and type F fly ash, respectively. To improve the reactivity, the selected clay was ground in a ball miller and heated to 700 °C. The binary mixtures were alkali activated with NaOH solution at 4 M and 8 M, and the activated pastes were cured at room temperature and relative humidity >90% in a climatic chamber. Heat flow, total heat and compressive strength (2, 7 and 28 days) were determined. The hardened pastes were characterized by X-ray powder diffraction (XRPD), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX). Results show that the main reaction product in all samples is a gel or mixture of C-A-S-H/(N, C)-A-S-H type gel depending on...
Applied Sciences, 2020
The present study explores the effect of activating solution concentration (4, 6 and 8 M NaOH) on... more The present study explores the effect of activating solution concentration (4, 6 and 8 M NaOH) on mechanically and thermally pre-treated carbonate-high illite clay (LCR). Pastes were prepared with an alkaline solution/clay (S/B) ratio of 0.55, which were cured at room temperature and relative humidity > 90% in a climatic chamber. At two and 28 days, compressive mechanical strength was determined, and the reaction products were characterised by X-ray Powder Diffraction analysis (XRPD), Fourier-transform infrared spectroscopy (FTIR) and Scanning Electron Microscopy - Energy Dispersive X-ray spectroscopy (SEM/EDX). Results obtained showed that the presence of reactive calcium in the starting clay induces co-precipitation of a mix of gels: An aluminium-enriched C-S-H gel (C-A-S-H) and a N-A-S-H gel, in which sodium is partially replaced by calcium (N,C)-A-S-H. Pastes prepared with higher (6 or 8 M) activator concentrations exhibit a more compact matrix than the ones prepared with 4 M...
Applied Clay Science, 2018
Abstract The present study focuses on the assessment of the effects of different activation metho... more Abstract The present study focuses on the assessment of the effects of different activation methods on carbonate-rich clays, to understand the mineralogical differences originated and to exploit such information to industry for traditional and innovative applications, especially as a precursor for alkali activated binders. Illite carbonate-rich clay samples were subjected to thermal activation in ox/red atmosphere between 400 and 900 °C, mechanical activation (grinding for 5, 10 and 15 min) and to a combination of such treatments. Mineralogical and textural changes in the activated samples were evaluated through X-ray powder diffraction, Fourier transform infrared spectroscopy and thermal techniques. The activated samples with the highest content of amorphous phase underwent leaching tests in a 3 M NaOH solution by means of inductively coupled plasma-mass spectrometry. The application of the three processing routines, yielded three types of activated clays with different leaching modes of Si, Al, K and Ca: (1) high energy grinding preferentially delaminates clay minerals and reduces the grain size of calcite. K leaching reaches the highest values; (2) thermal heating at 800 °C increases relatively the Si/Al solubility ratio, but the absolute concentrations of these elements are equal or lower than those obtained from ground clays. The relatively higher leaching of Ca is influenced by the formation of non-stoichiometric and poorly crystalline Ca-silicates and -aluminosilicates; (3) high energy grinding combined with heating treatment yields an extended amorphisation, mainly at the expense of clay minerals, with the highest leaching of Si and Al, and the lowest of Ca. New formed K-feldspars inhibit the concentration of K in alkaline solution.
Počítačová podpora v archeologii III. Sborník příspěvků z deváté konference konané v Litomyšli 19.–21. 5. 2010. Praha 2010, Dec 1, 2010
Příspěvek se zaobírá postupem dokumentace klenby Manského paláce na hradě Bezděz metodou stereofo... more Příspěvek se zaobírá postupem dokumentace klenby Manského paláce na hradě Bezděz metodou stereofotogrammetrie a průsekové fotogrammetrie, shrnuje a dokladuje jeho výsledky.
Polymers
This work deals with the investigation of alkaline binders obtained from binary mixtures of carbo... more This work deals with the investigation of alkaline binders obtained from binary mixtures of carbonate-rich illitic clay from deposits in southern Italy and two industrial by-products with very different total composition and calcium content, i.e., blast furnace slag and type F fly ash, respectively. To improve the reactivity, the selected clay was ground in a ball miller and heated to 700 °C. The binary mixtures were alkali activated with NaOH solution at 4 M and 8 M, and the activated pastes were cured at room temperature and relative humidity >90% in a climatic chamber. Heat flow, total heat and compressive strength (2, 7 and 28 days) were determined. The hardened pastes were characterized by X-ray powder diffraction (XRPD), Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX). Results show that the main reaction product in all samples is a gel or mixture of C-A-S-H/(N, C)-A-S-H type gel depending on...
Applied Sciences, 2020
The present study explores the effect of activating solution concentration (4, 6 and 8 M NaOH) on... more The present study explores the effect of activating solution concentration (4, 6 and 8 M NaOH) on mechanically and thermally pre-treated carbonate-high illite clay (LCR). Pastes were prepared with an alkaline solution/clay (S/B) ratio of 0.55, which were cured at room temperature and relative humidity > 90% in a climatic chamber. At two and 28 days, compressive mechanical strength was determined, and the reaction products were characterised by X-ray Powder Diffraction analysis (XRPD), Fourier-transform infrared spectroscopy (FTIR) and Scanning Electron Microscopy - Energy Dispersive X-ray spectroscopy (SEM/EDX). Results obtained showed that the presence of reactive calcium in the starting clay induces co-precipitation of a mix of gels: An aluminium-enriched C-S-H gel (C-A-S-H) and a N-A-S-H gel, in which sodium is partially replaced by calcium (N,C)-A-S-H. Pastes prepared with higher (6 or 8 M) activator concentrations exhibit a more compact matrix than the ones prepared with 4 M...
Applied Clay Science, 2018
Abstract The present study focuses on the assessment of the effects of different activation metho... more Abstract The present study focuses on the assessment of the effects of different activation methods on carbonate-rich clays, to understand the mineralogical differences originated and to exploit such information to industry for traditional and innovative applications, especially as a precursor for alkali activated binders. Illite carbonate-rich clay samples were subjected to thermal activation in ox/red atmosphere between 400 and 900 °C, mechanical activation (grinding for 5, 10 and 15 min) and to a combination of such treatments. Mineralogical and textural changes in the activated samples were evaluated through X-ray powder diffraction, Fourier transform infrared spectroscopy and thermal techniques. The activated samples with the highest content of amorphous phase underwent leaching tests in a 3 M NaOH solution by means of inductively coupled plasma-mass spectrometry. The application of the three processing routines, yielded three types of activated clays with different leaching modes of Si, Al, K and Ca: (1) high energy grinding preferentially delaminates clay minerals and reduces the grain size of calcite. K leaching reaches the highest values; (2) thermal heating at 800 °C increases relatively the Si/Al solubility ratio, but the absolute concentrations of these elements are equal or lower than those obtained from ground clays. The relatively higher leaching of Ca is influenced by the formation of non-stoichiometric and poorly crystalline Ca-silicates and -aluminosilicates; (3) high energy grinding combined with heating treatment yields an extended amorphisation, mainly at the expense of clay minerals, with the highest leaching of Si and Al, and the lowest of Ca. New formed K-feldspars inhibit the concentration of K in alkaline solution.
Počítačová podpora v archeologii III. Sborník příspěvků z deváté konference konané v Litomyšli 19.–21. 5. 2010. Praha 2010, Dec 1, 2010
Příspěvek se zaobírá postupem dokumentace klenby Manského paláce na hradě Bezděz metodou stereofo... more Příspěvek se zaobírá postupem dokumentace klenby Manského paláce na hradě Bezděz metodou stereofotogrammetrie a průsekové fotogrammetrie, shrnuje a dokladuje jeho výsledky.