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Your search keyword '"Bignozzi, Maria Chiara"' showing total 41 results
Start Over Author "Bignozzi, Maria Chiara" Publisher elsevier bv
41 results on '"Bignozzi, Maria Chiara"'

10. An innovative multi-component fluoropolymer-based coating on outdoor patinated bronze for Cultural Heritage: Durability and reversibility

Author

Masi, Giulia, primary, Bernardi, Elena, additional, Martini, Carla, additional, Vassura, Ivano, additional, Skrlep, Luka, additional, Švara Fabjan, Erika, additional, Gartner, Nina, additional, Kosec, Tadeja, additional, Josse, Claudie, additional, Esvan, Jerome, additional, Bignozzi, Maria Chiara, additional, Robbiola, Luc, additional, and Chiavari, Cristina, additional

Published
2020
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38. Alkali activated lightweight mortars for passive fire protection: A preliminary study

Author

Raffaela Moricone, Lorenza Carabba, Alessandro Tugnoli, Giordano Emrys Scarponi, Maria Chiara Bignozzi, Carabba, Lorenza, Moricone, Raffaela, Scarponi, Giordano Emry, Tugnoli, Alessandro, and Bignozzi, Maria Chiara

Subjects
Materials science, 0211 other engineering and technologies, 020101 civil engineering, Foaming agent, Fly ash, 02 engineering and technology, Geopolymer, 0201 civil engineering, Thermal conductivity, Passive fire protection, 021105 building & construction, Fire resistance, General Materials Science, Composite material, Civil and Structural Engineering, Cement, Waste processing, Aggregate (composite), Building and Construction, Alkali activated material, Materials Science (all), Mortar
Abstract

Alkali activated lightweight mortars, obtained by room temperature activation of coal fly ash, were studied as passive fire protection systems for steel elements. Physical, mechanical and thermal properties were investigated as a function of the compositional Si/Al molar ratio and of the amount of lightweight aggregate and foaming agent. Experimental findings were used as input data to assess their fire resistance by finite volume simulations. Results pointed out that the optimized alkali activated lightweight mortars are able to outperform alternative commercial cement-based mortars, thus representing a promising technology.

Published
2019

39. Characteristics and rheological behaviour of spray-dried powders for porcelain stoneware slabs

Author

Maria Chiara Bignozzi, Chiara Zanelli, Michele Dondi, Guia Guarini, Roberto Soldati, Sandra Fazio, Soldati, Roberto, Zanelli, Chiara, Guarini, Guia, Fazio, Sandra, Bignozzi, Maria Chiara, and Dondi, Michele

Subjects
Materials Chemistry2506 Metals and Alloys, Materials science, Hausner ratio, Agglomerate, Compaction, Ceramics and Composite, 02 engineering and technology, Porcelain stoneware, Rheology, Materials Chemistry, Ceramic, Composite material, 020502 materials, 021001 nanoscience & nanotechnology, Bulk density, 0205 materials engineering, Agglomerates, visual_art, Ceramics and Composites, visual_art.visual_art_medium, Powder rheology, Tile, Particle size, 0210 nano-technology, Spray-dried powder
Abstract

The technological behavior of porcelain stoneware bodies during deposition and pressing of large slabs depends on the rheological properties of spray-dried powders and the way they affect compaction. Although the literature offers some insights into the characteristics of spray-dried powders for ceramic tiles, no data are available on bodies utilized by novel technologies for large slabs (>4 m2). In order to fill this gap, a systematic approach to properties and behavior of spray-dried powders for porcelain stoneware slabs was carried out. For this purpose, twenty industrially-manufactured spray-dried powders were characterized for intrinsic features (particle size and agglomerate size distribution; shape and moisture distribution in function of agglomerate size) and rheological properties (mass flow, static and dynamic angles of repose, poured and tap density, Hausner ratio). The effect of intrinsic characteristics on the flowability of powders was appraised, as the mutual relationships between the rheological parameters, in order to unveil the best parameters to be used in ceramic tile production. Two broad classes of spray-dried powders occur with a finer and a coarser agglomerate size distribution. Results reveal that ceramic powders are free-flowing, with rheological properties fluctuating in a rather narrow range of values, which makes hard to see significant relationships among the various methods (the only strict correlation is between mass flow rate and tap density). Flowability mainly depends on the occurrence of coarser aggregates, particularly those irregular in shape, stemming from coalescence of three or more individual agglomerates. A phenomenological description of how the spray-dried powders behave in the deposition on tape and the early stage of compaction is outlined.

Published
2018

40. Elastic properties of porous porcelain stoneware tiles

Author

Eva Gregorová, Maria Chiara Bignozzi, Francesca Prete, Elisa Rambaldi, Willi Pabst, Rambaldi, Elisa, Pabst, Willi, Gregorová, Eva, Prete, Francesca, and Bignozzi, Maria Chiara

Subjects
Materials Chemistry2506 Metals and Alloys, Materials science, Surfaces, Coatings and Film, Sintering, Ceramics and Composite, 02 engineering and technology, Phase composition, 01 natural sciences, Porcelain stoneware, 0103 physical sciences, Materials Chemistry, medicine, Composite material, Porosity, 010302 applied physics, Elastic propertie, Electronic, Optical and Magnetic Material, Process Chemistry and Technology, Stiffness, 021001 nanoscience & nanotechnology, Microstructure, Surfaces, Coatings and Films, Electronic, Optical and Magnetic Materials, Exponential function, Ceramics and Composites, medicine.symptom, 0210 nano-technology
Abstract

Porcelain stoneware tiles are industrially processed by using high sintering temperatures and fast firing cycles that result in products characterized by an almost impervious surface layer surrounding a rather porous bulk material. Since mechanical properties are affected by porosity, the knowledge of the material stiffness is an important parameter to define the service behavior of tiles. In the present investigation, porcelain stoneware samples having different closed porosity were investigated in order to understand the influence of the porosity on the elastic constants of the materials. Based on the quantitative XRD phase composition, elastic constants have been calculated via Voigt-Reuss-Hill averaging, and the influence of porosity has been taken into account via power-law and exponential relations. It is shown that the effective elastic constants predicted by exponential and power-law relations are in agreement with experimental values. It may be concluded that for this class of materials, in the porosity range below 14–16%, both exponential and power-law relations are helpful tools to design tiles with controlled microstructure and tailored mechanical properties.

Published
2017

41. Influence of fine aggregates on the microstructure, porosity and chemico-mechanical stability of inorganic polymer concretes

Author

Rosa Taurino, Duangrudee Chaysuwan, Elie Kamseu, Luisa Barbieri, Chayanee Tippayasam, Maria Chiara Bignozzi, Cristina Leonelli, Chiara Ponzoni, Kamseu, Elie, Ponzoni, Chiara, Tippayasam, Chayanee, Taurino, Rosa, Chaysuwan, Duangrudee, Bignozzi, Maria Chiara, Barbieri, Luisa, and Leonelli, Cristina

Subjects
Glass recycling, Inorganic polymer, Materials science, Moisture, Building and Construction, Aluminosilicate fines, Inorganic polymer concretes, MicrostructureDurability, Strength, Porosity, Aluminosilicate fine, Aluminosilicate fines, Microstructure, Durability, Amorphous solid, Crystallinity, Inorganic polymer concrete, General Materials Science, Materials Science (all), Strength, MicrostructureDurability, Composite material, Inorganic polymer concretes, Porosity, Curing (chemistry), Civil and Structural Engineering
Abstract

This work investigates the effects of the structure, the bulk chemical composition and amount of the aluminosilicate fines on the strength development, pore refinement, water permeability, moisture control capacity and the microstructure of inorganic polymer concretes (IPC). The amorphous fines, one from pumice and another from recycled glass, presented sponge-like microstructure with tortuous pore network that maintained the presence of fine capillary pores while semi-crystalline feldspar sludge, the third type of fine aggregates used for this study, showed more dense and compact microstructure that explain the higher strength enhancement. Both amorphous and semicrystalline fines contributed to decrease the porosity, improve the strength and microstructure. However, based on the moisture control capacity and the durability indicators, the fine aggregate derived from semicrystalline feldspar was found to be more appropriate and efficient for the development of IPC at short time scale of curing. Pumice fine aggregate was found to be effective only with a long term curing. (C) 2015 Elsevier Ltd. All rights reserved.

Published
2015

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