15 results on '"Bignozzi, Maria Chiara"'
Search Results
2. Effect of the chemical composition of different types of recycled glass used as aggregates on the ASR performance of cement mortars.
- Author
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Saccani, Andrea, Bignozzi, Maria Chiara, Barbieri, Luisa, Lancellotti, Isabella, and Bursi, Elena
- Subjects
- *
CATHODE ray tubes , *FLUORESCENT lamps , *CRYSTAL glass , *GLASS container manufacturing , *MORTAR , *MAINTENANCE , *LAMP design & construction - Abstract
Glass with different chemical compositions, deriving from separate collection, has been used as fine aggregate to formulate cementitious mortars, substituting natural sand. Glass coming from cathode-ray tube monitors, fluorescent lamps, and crystal glass (from production of home décor items) along with glass deriving from soda-lime glass containers, which has been taken as a reference, have been investigated. Glass solubility has been determined in alkaline environment similar to the one inside the cementitious composite. Alkali silica reaction has been tested on glass modified cement mortar in different accelerated conditions. Mortar samples containing glass with chemical composition different with respect to soda-lime glass are subjected to alkali silica reaction. This behaviour is largely dependent on the ratio among modifier and stabilizer oxides in the glass. The same ratio affects glass solubility and consequently composition of expanding gels when alkali silica reactions take place. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
3. Alternative blended cement with ceramic residues: Corrosion resistance investigation on reinforced mortar
- Author
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Bignozzi, Maria Chiara and Bonduà, Stefano
- Subjects
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CEMENT , *MICROSTRUCTURE , *CERAMICS , *CORROSION & anti-corrosives , *MORTAR , *PORTLAND cement , *CONCRETE durability - Abstract
Abstract: Blended cements are largely used for concrete: they are usually considered cements with a low environmental impact, as they require less clinker than ordinary Portland cement (OPC). Different constituents can be used as supplementary clinker component usually leading to cement with high resistance to outdoor environment. Polishing residue (PR), coming from porcelain stoneware tiles production, can be successfully used as new constituent for blended cement, however its action for enhancing the durability of cement matrix must be assessed. With this purpose, electrochemical tests (half cell potential, impressed voltage and linear polarization techniques) have been carried out on steel reinforced mortar samples, prepared using a 25% PR based cement and 100% OPC as binder and exposed to a 3.5% NaCl solution. The corrosion resistance results and microstructure analysis highlight better durability performances for PR based cement than those exhibited by OPC, mainly for curing time >28days. [Copyright &y& Elsevier]
- Published
- 2011
- Full Text
- View/download PDF
4. Acoustic emission study of heat-induced cracking in fly ash-based alkali-activated pastes and lightweight mortars.
- Author
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Carabba, Lorenza, Pirskawetz, Stephan, Krüger, Simone, Gluth, Gregor J.G., and Bignozzi, Maria Chiara
- Subjects
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ACOUSTIC emission , *GLASS transition temperature , *MORTAR , *FLY ash , *HIGH temperatures , *FLIES - Abstract
Alkali-activated fly ashes have been proposed for various applications where resistance against high temperatures is required, yet several details regarding the response of these materials to heat-exposure need to be clarified. In the present study, heat-induced cracking in fly ash-based alkali-activated pastes and lightweight mortars was analyzed by in-situ acoustic emission (AE) detection during complete heating-cooling cycles (up to ∼1100 °C), augmented by thermogravimetry and ex-situ SEM and XRD analyses. The applicability of the lightweight mortars as passive fire protection coatings was assessed by recording temperature-time curves of mortar-coated steel plates. Cracking during heating was limited and associated exclusively with the dehydration of the materials in the temperature range ∼90–360 °C. However, samples heated to temperatures above ∼600 °C exhibited intense cracking on cooling. This was attributed to differential deformations caused by local sintering and partial melting at the glass transition temperature, and subsequent quenching on cooling. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
5. Valorization of spent cooking oils in hydrophobic waste-based lime mortars for restorative rendering applications.
- Author
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Pahlavan, Parsa, Manzi, Stefania, Rodriguez-Estrada, Maria Teresa, and Bignozzi, Maria Chiara
- Subjects
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VEGETABLE oils , *MORTAR , *HYDROPHOBIC compounds , *ARCHITECTURAL rendering , *POZZOLANIC reaction - Abstract
The suitability of new lime mortars for restorative rendering applications was investigated. Air-, formulated- and hydraulic-lime mortars were synthesized with inclusion of two different types of spent sunflower cooking oils and, when necessary, brick waste powder as pozzolanic addition. The results of spent cooking oils addition in the mortars exhibited promising hydrophobic effects, such as sorptivity reduction up to 60 times and improvement of superficial durability. Addition of high-oleic acid cooking oil in 13 wt% in the formulated and hydraulic lime mortars significantly increased their hydrophobicity without worsening their mechanical strengths. All the investigated mortars exhibited appropriate indexes as restorative materials. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
6. Fly ash-based one-part alkali activated mortars cured at room temperature: Effect of precursor pre-treatments
- Author
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Giulia Masi, Maria Chiara Bignozzi, Alessandro Filipponi, Masi, Giulia, Filipponi, Alessandro, and Bignozzi, Maria Chiara
- Subjects
Pre treatment ,Precursor pre-treatment ,Heat curing ,Materials science ,Room-temperature curing ,One-part geopolymer ,Metallurgy ,Clay industries. Ceramics. Glass ,Mechanical properties ,Fly ash ,Electronic, Optical and Magnetic Materials ,Biomaterials ,TP785-869 ,Alkali activation ,Materials Chemistry ,Ceramics and Composites ,Alkali activated ,One-part geopolymers ,Caustic (optics) ,Mortar ,Mechanical propertie ,Microstructure - Abstract
One-part or “just add water” alkali activated materials (AAMs) have attracted a lot of attention thanks to the use of solid alkaline activators that makes these materials more suitable to commercialization compared to conventional AAMs (two-part). This is mainly because large quantities of caustic solutions should be handled for producing conventional AAMs. So, one-part AAMs have a great potential for in-situ applications. However, heat curing (
- Published
- 2021
7. Alkali activated lightweight mortars for passive fire protection: A preliminary study
- Author
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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
8. Assessment of reclaimed asphalt pavement (RAP) as recycled aggregate for concrete.
- Author
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Masi, Giulia, Michelacci, Alessandra, Manzi, Stefania, and Bignozzi, Maria Chiara
- Subjects
- *
ASPHALT pavement recycling , *MORTAR , *THAWING , *CONCRETE durability , *CONCRETE , *EXPANSION & contraction of concrete , *PARTICLE size distribution - Abstract
[Display omitted] • Reclaimed asphalt pavement (RAP) was tested as aggregate replacement for concrete. • Five types of RAP sourced by different Italian collection sites were characterized. • RAP shows irregular porous surface due to bitumen covering the natural aggregate. • RAP shows hydrophobic behavior. • RAP exhibits dimensional stability and frost resistance. A study about the performances of reclaimed asphalt pavement (RAP) sourced from 5 different Italian collection sites is presented to evaluate RAP as aggregate for concrete. Several RAP properties were investigated: physical properties (particles size distribution, water absorption, porosity, wettability), microstructure by microscopy, dimensional stability (drying shrinkage of mortar and concrete with 100% of RAP as aggregates) and durability assessment by freezing-thawing cycles. Several differences between RAP and natural aggregates used for concrete were highlighted. The use of RAP as recycled aggregate for concrete is a promising route, but a complete characterization is needed to ensure concrete performance and durability. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
9. Improvement of historic reinforced concrete/mortars by impregnation and electrochemical methods.
- Author
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Franzoni, Elisa, Varum, Humberto, Natali, Maria Elia, Bignozzi, Maria Chiara, Melo, José, Rocha, Luciana, and Pereira, Eduarda
- Subjects
- *
REINFORCED concrete , *MORTAR , *ELECTROCHEMICAL analysis , *MAINTAINABILITY (Engineering) , *CYCLIC loads , *EARTHQUAKES , *CONCRETE durability , *BOND strengths - Abstract
Abstract: Old reinforced concrete (RC) structures often exhibit unsatisfactory performances in terms of both residual serviceability and seismic behavior. The durability requirements were not considered at all at the age of design and construction, exposing such structures to severe decay in aggressive urban and/or industrial environment; in the meantime, the use of plain steel bars (with poor bond strength) was common at the age of construction and this jeopardizes the RC performance under cyclic load reversals like those induced by earthquakes. In this paper, the deep impregnation of cement-based mortars and concrete with a solution of ethyl silicate and with electrochemical treatments by means of a solution of sodium carbonate was investigated, with a twofold aim: (1) increasing the bond strength of the embedded plain steel bars in existing structures without any need for demolition and (2) increasing the durability and safety of the reinforced concrete elements. Both the treatments are already exploited in other fields: ethyl silicate solutions are widely used for stone consolidation (and only recently proposed for concrete surface protection), while migration of sodium carbonate under DC voltage is used for RC realkalization. In the present study these treatments are expected to penetrate inside mortar and concrete and to modify their microstructure, hence improving their properties. The effects of the treatments are investigated by comparing the characteristics of treated and untreated mortar and concrete samples reinforced with plain bars, in terms of penetration inside the samples, pull-out strength, water absorption, pore size distribution, carbonation resistance and corrosion resistance. [Copyright &y& Elsevier]
- Published
- 2014
- Full Text
- View/download PDF
10. Valorization of organic additions in restorative lime mortars: Spent cooking oil and albumen
- Author
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Parsa Pahlavan, Maria Chiara Bignozzi, Stefania Manzi, Antonio Sansonetti, Pahlavan, Parsa, Manzi, Stefania, Sansonetti, Antonio, and Bignozzi, Maria Chiara
- Subjects
Cooking oil ,Hydrophobicity ,0211 other engineering and technologies ,02 engineering and technology ,Restorative mortar ,engineering.material ,Hydraulic propertie ,021105 building & construction ,General Materials Science ,Air lime ,Civil and Structural Engineering ,Lime ,Brick ,Chemistry ,Building and Construction ,Biodegradable waste ,021001 nanoscience & nanotechnology ,Pulp and paper industry ,Durability ,Restorative mortars ,Ceramic waste ,Hydraulic properties ,Agro-food waste ,engineering ,Setting time ,Materials Science (all) ,Mortar ,0210 nano-technology - Abstract
Air- and formulated lime mortars with pulverized brick waste were synthesized with addition of two organic waste-based additives: spent cooking oil and albumen. The addition of spent oil in the mortar induced significant hydrophobic effects, but decreased permeability values and setting kinetics. Parallel additions of oil and albumen in lime mortars significantly increased their hydrophobicity and superficial durability without retarding their setting time thanks to role of fatty acids and unfolded proteins under alkaline conditions. The parallel valorization showed high potentials in synthesis of restorative mortars design with low environmental impact and high respect to the feature of historic mortars. (C) 2018 Elsevier Ltd. All rights reserved.
- Published
- 2018
- Full Text
- View/download PDF
11. Binders alternative to Portland cement and waste management for sustainable construction—part 1
- Author
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Marco Ormellese, Andrea Brenna, Rosa Di Mundo, Chiara Giosuè, Luca Di Palma, Bartolomeo Coppola, Luigi Coppola, Denny Coffetti, G Scoccia, Paola Scarfato, Letterio Mavilia, Giorgio Vilardi, Ottavio Marino, Tommaso Pastore, Elena Crotti, Milena Marroccoli, Franco Medici, Giuliana Taglieri, Francesca Tittarelli, Valeria Daniele, Elena Redaelli, Maria Chiara Bignozzi, Sergio Lorenzi, Tiziano Bellezze, Alida Mazzoli, Marta Cappai, Claudio Ferone, Stefania Manzi, Raffaele Cioffi, Giorgio Pia, Sebastiano Candamano, Fabio Maria Bolzoni, Ludovica Casnedi, Maria Cristina Mascolo, Maria Vittoria Diamanti, Francesco Todaro, Patrizia Frontera, MariaPia Pedeferri, Glauco Merlonetti, Ilenia Farina, Sabino De Gisi, Andrea Petrella, Matteo Maria Gastaldi, Federica Lollini, Alberto Belli, Marina Cabrini, Valeria Corinaldesi, Ombretta Cocco, Domenico Caputo, Maddalena Carsana, Fan Yang, Loredana Incarnato, Jacopo Donnini, Alessandra Mobili, Antonio Telesca, Fortunato Crea, Michele Notarnicola, Giuseppina Roviello, Paola Meloni, Luciano Di Maio, Francesco Colangelo, Francesco Delogu, Barbara Liguori, Coppola, Luigi, Bellezze, Tiziano, Belli, Alberto, Bignozzi, Maria Chiara, Bolzoni, Fabio, Brenna, Andrea, Cabrini, Marina, Candamano, Sebastiano, Cappai, Marta, Caputo, Domenico, Carsana, Maddalena, Casnedi, Ludovica, Cioffi, Raffaele, Cocco, Ombretta, Coffetti, Denny, Colangelo, Francesco, Coppola, Bartolomeo, Corinaldesi, Valeria, Crea, Fortunato, Crotti, Elena, Daniele, Valeria, De Gisi, Sabino, Delogu, Francesco, Diamanti, Maria Vittoria, Di Maio, Luciano, Di Mundo, Rosa, Di Palma, Luca, Donnini, Jacopo, Farina, Ilenia, Ferone, Claudio, Frontera, Patrizia, Gastaldi, Matteo, Giosuè, Chiara, Incarnato, Loredana, Liguori, Barbara, Lollini, Federica, Lorenzi, Sergio, Manzi, Stefania, Marino, Ottavio, Marroccoli, Milena, Mascolo, Maria Cristina, Mavilia, Letterio, Mazzoli, Alida, Medici, Franco, Meloni, Paola, Merlonetti, Glauco, Mobili, Alessandra, Notarnicola, Michele, Ormellese, Marco, Pastore, Tommaso, Pedeferri, Maria Pia, Petrella, Andrea, Pia, Giorgio, Redaelli, Elena, Roviello, Giuseppina, Scarfato, Paola, Scoccia, Giancarlo, Taglieri, Giuliana, Telesca, Antonio, Tittarelli, Francesca, Todaro, Francesco, Vilardi, Giorgio, and Yang, Fan
- Subjects
Engineering ,alternative binders ,Building materials ,concrete ,Portland cement ,sustainability ,waste management ,Alkalies ,Aluminum Compounds ,Aluminum Silicates ,Calcium Compounds ,Corrosion ,Sulfur Compounds ,Waste Management ,Construction Materials ,Green Chemistry Technology ,Biophysics ,Bioengineering ,Biomaterials ,Biomedical Engineering ,0211 other engineering and technologies ,02 engineering and technology ,law.invention ,law ,021105 building & construction ,Sulfur Compound ,Waste management ,General Medicine ,021001 nanoscience & nanotechnology ,Environmentally friendly ,Calcium Compound ,cement ,binders ,construction materials ,Building materials, concrete, Portland cement, sustainability, alternative binders, waste management ,Alkalie ,0210 nano-technology ,Settore ING-IND/22 - Scienza e Tecnologia dei Materiali ,alternative binder ,Clay ,business.industry ,Biomaterial ,Construction Material ,Sustainable construction ,Biophysic ,Aluminum Silicate ,Greenhouse gas ,Sustainability ,Building material ,Mortar ,business ,Aluminum Compound - Abstract
This review presents “a state of the art” report on sustainability in construction materials. The authors propose different solutions to make the concrete industry more environmentally friendly in order to reduce greenhouse gases emissions and consumption of non-renewable resources. Part 1—the present paper—focuses on the use of binders alternative to Portland cement, including sulfoaluminate cements, alkali-activated materials, and geopolymers. Part 2 will be dedicated to traditional Portland-free binders and waste management and recycling in mortar and concrete production.
- Published
- 2018
12. Use of digital image analysis to determine fracture properties of alkali-activated mortars.
- Author
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Baietti, Giulia, Quartarone, Giovanni, Carabba, Lorenza, Manzi, Stefania, Carloni, Christian, and Bignozzi, Maria Chiara
- Subjects
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MORTAR , *IMAGE analysis , *DIGITAL image correlation , *FLY ash , *ALKALIES , *DIGITAL images - Abstract
• The fracture properties of three alkali-activated mortars are studied. • Low values of fracture energy might be associated with the presence of unreacted FA. • The fracture energy depends on the type of aggregate used. • Digital image correlation can be used to estimate the size of the FPZ. Results of three-point bending tests on notched beams cast with three alkali-activated mortars that differ by the type and size of the aggregates are presented. Digital image correlation is used to estimate the size of the fracture process zone. The fracture energy is computed by means of the work-of-fracture method and found to be strongly dependent on the type of aggregate used and does not differ whether the LDVT or DIC load-deflection curves are used. Finally, low values of the fracture energy in alkali-activated mortars might be associated with the presence of unreacted fly ash. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
13. Valorization of spent cooking oils in hydrophobic waste-based lime mortars for restorative rendering applications
- Author
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Maria Teresa Rodriguez-Estrada, Maria Chiara Bignozzi, Parsa Pahlavan, Stefania Manzi, Pahlavan, Parsa, Manzi, Stefania, Rodriguez-Estrada, Maria Teresa, and Bignozzi, Maria Chiara
- Subjects
Restorative rendering ,Materials science ,Cooking oil ,Sorptivity ,Hydrophobicity ,0211 other engineering and technologies ,02 engineering and technology ,engineering.material ,complex mixtures ,Rendering (animal products) ,021105 building & construction ,General Materials Science ,Air lime ,Lime ,Civil and Structural Engineering ,Hydraulic lime ,Formulated lime ,Waste management ,Spent cooking oil ,Pozzolan ,Building and Construction ,021001 nanoscience & nanotechnology ,Durability ,Ceramic waste ,engineering ,Materials Science (all) ,Mortar ,0210 nano-technology - Abstract
The suitability of new lime mortars for restorative rendering applications was investigated. Air-, formulated- and hydraulic-lime mortars were synthesized with inclusion of two different types of spent sunflower cooking oils and, when necessary, brick waste powder as pozzolanic addition. The results of spent cooking oils addition in the mortars exhibited promising hydrophobic effects, such as sorptivity reduction up to 60 times and improvement of superficial durability. Addition of high-oleic acid cooking oil in 13 wt% in the formulated and hydraulic lime mortars significantly increased their hydrophobicity without worsening their mechanical strengths. All the investigated mortars exhibited appropriate indexes as restorative materials.
- Published
- 2017
14. Effect of the chemical composition of different types of recycled glass used as aggregates on the ASR performance of cement mortars
- Author
-
Isabella Lancellotti, Luisa Barbieri, Andrea Saccani, Elena Bursi, Maria Chiara Bignozzi, Saccani, Andrea, Bignozzi, Maria Chiara, Barbieri, Luisa, Lancellotti, Isabella, and Bursi, Elena
- Subjects
Soda-lime glass ,Glass recycling ,Glass production ,Materials science ,alkali silica reactions, glass recycling, recycled aggregates, glass chemical composition ,0211 other engineering and technologies ,02 engineering and technology ,Porous glass ,021105 building & construction ,Recycled aggregate ,General Materials Science ,Composite material ,Civil and Structural Engineering ,business.industry ,Building and Construction ,021001 nanoscience & nanotechnology ,Lead glass ,Glass chemical composition ,visual_art ,visual_art.visual_art_medium ,Alkali–silica reaction ,Cementitious ,Materials Science (all) ,Mortar ,0210 nano-technology ,business ,Alkali silica reaction - Abstract
Glass with different chemical compositions, deriving from separate collection, has been used as fine aggregate to formulate cementitious mortars, substituting natural sand. Glass coming from cathode-ray tube monitors, fluorescent lamps, and crystal glass (from production of home decor items) along with glass deriving from soda-lime glass containers, which has been taken as a reference, have been investigated. Glass solubility has been determined in alkaline environment similar to the one inside the cementitious composite. Alkali silica reaction has been tested on glass modified cement mortar in different accelerated conditions. Mortar samples containing glass with chemical composition different with respect to soda-lime glass are subjected to alkali silica reaction. This behaviour is largely dependent on the ratio among modifier and stabilizer oxides in the glass. The same ratio affects glass solubility and consequently composition of expanding gels when alkali silica reactions take place.
- Published
- 2017
15. Valorization of brick waste by alkali-activation: A study on the possible use for masonry repointing
- Author
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Enrico Sassoni, Elisa Franzoni, Parsa Pahlavan, Maria Chiara Bignozzi, Sassoni, Enrico, Pahlavan, Parsa, Franzoni, Elisa, and Bignozzi, Maria Chiara
- Subjects
Materials science ,0211 other engineering and technologies ,02 engineering and technology ,engineering.material ,Geopolymer ,021105 building & construction ,Materials Chemistry ,Repointing ,Composite material ,Porosity ,Curing (chemistry) ,Lime ,business.industry ,Process Chemistry and Technology ,Masonry ,021001 nanoscience & nanotechnology ,Alkali metal ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Ceramic waste ,Efflorescence ,SiO2/Al2O3 ratio ,Sustainability ,Ceramics and Composites ,engineering ,Cultural heritage ,Historic mortar ,Mortar ,0210 nano-technology ,business - Abstract
Alkali-activation of brick waste has recently been proposed as a sustainable route to develop pastes/mortars with tailored mechanical properties and pore system. In this study, the suitability of using pastes from brick waste alkali-activation for repointing existing masonries (i.e., filling the most external part of mortar joints, lost due to deterioration processes) was investigated. Five different formulations (having SiO 2 /Al 2 O 3 molar ratio ranging from 1.4 to 0.4) and two different curing temperatures (room temperature and 50 °C) were investigated. Open porosity and efflorescence formation were found to decrease for decreasing SiO 2 /Al 2 O 3 ratio. Curing at high temperature generally favored geopolymerization and reduced efflorescence formation. Pastes with SiO 2 /Al 2 O 3 =0.8 and 0.9 exhibited open porosity and water vapor permeability fairly similar to those of historic lime-based mortars, thus proving to be potentially compatible with them. Further optimization of the mix design seems however necessary to reduce the formation of efflorescence.
- Published
- 2016
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