Geodesign project is a co-promotion project funded by the Portugal 2020 program with the aim of d... more Geodesign project is a co-promotion project funded by the Portugal 2020 program with the aim of developing new architectural products, integrating industrial waste and by-products generated by Portuguese companies, namely in the fields of steel, smelting, power stations, metallurgy and glassmaking. The partners of the project are W2V, SA, dedicated to waste management activities, Providência Design, dedicated to product design, the CVR technology center and the Portuguese universities of Minho and Trás-os-Montes and Alto Douro. Fly ash from thermoelectric plants, aluminum anodizing sludge and glass polishing dusts, among others, offer different plastic and chromatic qualities. When chemically integrated in the form of geopolymers or calcium-based materials, they exhibit different physical qualities of mechanical strength and aging. Taking into account their physical qualities and, consequently, the diversity of chromatic, textural and economical results, several functional products ...
The authors wish to acknowledge the Foundation for Science and Technology (FCT) for the financial... more The authors wish to acknowledge the Foundation for Science and Technology (FCT) for the financial support under project EXREACT (PTDC/CTM/65243/2006) and project DURATINET (Durable Transport Infrastructures in the Atlantic Area Network) for Transnational Programme Atlantic Area 2007-2003, co-financed by FEDER.
Portugal is one of the European countries in which built heritage is a testimony of its history. ... more Portugal is one of the European countries in which built heritage is a testimony of its history. In this context, the legacy of the decorative glazed tile coatings of facades must be preserved and restored. This research is dedicated to the conservation of such facades in the city of Ovar, considered an example due to its rich heritage in glazed tiles, a high percentage of which requires a deep intervention. Therefore, this work is focused on the study of lime renders serving as a support for this type of tile facades. For this, samples were collected from several buildings in the city, targeting their mechanical and physical study with the aim of producing compatible mortars to be used for application of detached tiles in these buildings and generally for the repair of the facades with glazed tile coatings. For this purpose, four lime mortar formulations with different volumetric ratios were composed. The aggregates used were: ordinary river sand and local gravel. In three of the mixtures, metakaolin was added, with the intention of acting as an artificial pozzolan and thus improving the performance of these mortars. The use of a pozzolanic addition promotes hardening of lime mortars in cases when the ingression of carbon dioxide is low as is the case of mortars placed below glazed tile coatings. These mortars were also tested in the laboratory taking into account their physical and mechanical characteristics. The mechanical characteristics determined were: modulus of elasticity by two different methods, compressive strength and flexural strength. In turn, the physical characteristics determined were: water vapour permeability and water absorption by total immersion and capillary action. The best mechanical behaviour (compressive and flexural) was observed in the mortar with pozzolanic additions. Similarly, the value of the modulus of elasticity was better in mortars with pozzolanic additions. The performance of these mortars was also adequate in terms of water behaviour. The mortars revealed suitable characteristics for application in building conservation situations concerning coating with glazed tiles. Keywords Conservation; glazed tiles; lime mortars; pozzolanic additions. Resumo Portugal é um dos países europeus em que o património construído é um testemunho da sua história. Neste contexto, o legado relativo aos azulejos de revestimento de fachada necessita de ser preservado. A investigação desenvolvida foi dedicada à conservação destas fachadas na cidade de Ovar, considerada exemplar devido à riqueza do seu património azulejar, do qual uma percentagem considerável necessita de acções de intervenção profundas. Por este motivo, o trabalho desenvolvido focou-se no estudo das argamassas de assentamento para este tipo de fachadas. De forma a permitir o estudo das argamassas antigas, foram retiradas várias amostras de argamassa de diversos edifícios da cidade. Estas amostras foram ensaiadas para determinar as suas características físicas e mecânicas com o objectivo de produzir argamassas compatíveis, passíveis de aplicação em casos de destacamento dos revestimentos azulejares nestes edifícios e, de uma forma geral, em fachadas azulejadas. Com este objectivo, quatro formulações de argamassas de cal, com diferentes traços volumétricos, foram efectuadas. Os agregados utilizados foram areia de rio siliciosa e uma areia local (saibro). Em três destas composições foi adicionado metacaulino, para que actuasse como uma pozolana artificial, melhorando o desempenho destas argamassas. A utilização de adições pozolânicas promove o endurecimento de argamassas de cal nos casos em que o ingresso de dióxido de carbono é baixo como é o caso de argamassas de assentamento localizadas sob uma camada de azulejo. Relativamente a estas argamassas, foram efectuados ensaios laboratoriais para testar as suas características físicas e mecânicas. Como características mecânicas, foi determinado o módulo de elasticidade utilizando duas metodologias diferentes, assim como a resistência à flexão e compressão. A determinação de características físicas incidiu na determinação da permeabilidade ao vapor de água, na absorção de água por imersão e na absorção de água por capilaridade. Verificou-se uma melhoria do comportamento mecânico (resistência à flexão e compressão) de argamassas com adição de pozolana. De forma similar verificou-se um valor mais elevado para o módulo de elasticidade destas argamassas. O comportamento destas argamassas relativamente à absorção de água revelou-se adequado. As argamassas testadas revelaram características apropriadas para a aplicação na conservação de edifícios no caso de utilização como argamassas de assentamento para revestimentos azulejares. Palavras-chave Conservação; azulejos; argamassas de cal; adições pozolânicas.
The durability of concrete structures is an important issue nowadays. Specifically in the case of... more The durability of concrete structures is an important issue nowadays. Specifically in the case of reinforced concrete bridges or other infrastructures one of the main form of environmental attack is the penetration of chloride ions, which leads to corrosion of concrete steel reinforcement. This study aims to evaluate the effect of the introduction of metakaolin and diatomite, two chemically and physically different pozzolans, on the resistance of concrete to the penetration of chlorides but also the effect on other properties of concrete, namely, its compressive strength and its porosity distribution. The results of this study show that the pozzolans physical and chemical characteristics have a strong influence on the pozzolans behavior and, consequently, on the concrete properties.
This research was focused on the use of the modified Chapelle test as a direct laboratory methodo... more This research was focused on the use of the modified Chapelle test as a direct laboratory methodology to access the pozzolanic activity of both experimental and commercial metakaolins. At the same time, this test was used in the evaluation of experimental metakaolins. This chemical test, performed during 16 hours at 90 °C, allows the quantification of portlandite fixed by the metakaolin sample. The calcium hydroxide that was not consumed is quantified by acid titration (HCl), and the test result is expressed in mg of fixed calcium hydroxide by g of metakaolin. According to this test, the pozzolanic activity of a metakaolin should not be less than 700 mg Ca(OH) 2 / g metakaolin. The modified Chapelle pozzolanic activity of six commercial metakaolins was evaluated between 920 and 1560 mg Ca(OH) 2 / g metakaolin. From the seven experimental metakaolins produced between 750 ºC and 940 ºC, a material with modified Chapelle pozzolanic activity value of 1240 mg Ca(OH) 2 / g metakaolin was obtained, which is similar to some tested commercial metakaolins produced at industrial scale. The metakaolin produced at 800 ºC was ground, resulting in a particle size reduction of ≈ 4x less and a consequent increase of 21 % in the pozzolanic activity.
The aim of this project is the development of new architectural products, integrating industrial ... more The aim of this project is the development of new architectural products, integrating industrial waste of class C and F, generated by companies based in the North of Portugal, namely in the fields of foundry, glass and paper. This selection results from technical consulting from “Waste to Value” assisted by the contribution of scientific research in geopolymers of the laboratory of the University of Minho, consultancy of the University of Trás-os-Montes and evaluation of resistance by the Materials laboratory of the University of Aveiro. The flying ash from thermoelectric plants, sludge from aluminium anodizing and glass polishing among others, offers different plastic and chromatic qualities. When chemically integrated by geopolymerization, they exhibit different physical qualities of strength, resistance to use and aging. Taking into consideration their physical qualities and, consequently, the resulting chromatic, textural and economic diversity, several functional products of wa...
Caracterização da interface azulejo/argamassa de fachadas históricas 55 Caracterização da interfa... more Caracterização da interface azulejo/argamassa de fachadas históricas 55 Caracterização da interface azulejo/argamassa de fachadas históricas
With the availability of commercial Natural cements (NC) for the conservation purposes raises a f... more With the availability of commercial Natural cements (NC) for the conservation purposes raises a fundamental question about the compatibility between historic and repair mortars. The properties of Natural cements are dependent on the geological location of the raw material extraction and also on the production parameters, both having an impact on the final properties of the mortars produced from each distinct. Therefore, the significance of preservation of 19th and 20th century heritage and selection of the proper binder compatible with the original materials necessitate the study of existing NCs, that nowadays are produced by several manufacturers. This work provides a complex study of the mortars prepared from three NCs available in the market: Groupe Prompt Vicat, France (NCPV); Cemento Collet Marfil (NCM) and Cemento Natural Tigre (NCT), both from Spain. Various mortar sets based on individual NC containing different binder/aggregate ratios and air lime additions were analyzed af...
With the availability of commercial Natural cements (NC) for the conservation purposes raises a f... more With the availability of commercial Natural cements (NC) for the conservation purposes raises a fundamental question about the compatibility between historic and repair mortars. The properties of Natural cements are dependent on the geological location of the raw material extraction and also on the production parameters, both having an impact on the final properties of the mortars produced from each distinct. Therefore, the significance of preservation of 19th and 20th century heritage and selection of the proper binder compatible with the original materials necessitate the study of existing NCs, that nowadays are produced by several manufacturers. This work provides a complex study of the mortars prepared from three NCs available in the market: Groupe Prompt Vicat, France (NCPV); Cemento Collet Marfil (NCM) and Cemento Natural Tigre (NCT), both from Spain. Various mortar sets based on individual NC containing different binder/aggregate ratios and air lime additions were analyzed af...
Aviso Legal A qualidade científica e os conteúdos das comunicações são da inteira responsabilidad... more Aviso Legal A qualidade científica e os conteúdos das comunicações são da inteira responsabilidade dos respetivos autores. O editor não aceita qualquer responsabilidade pela informação contida nas comunicações inseridas na presente publicação. Nos termos legais em vigor, é expressamente proibida a reprodução total ou parcial desta publicação, no seu todo ou em parte, não podendo ser reproduzida ou transmitida por qualquer forma ou processo eletrónico, mecânico ou outros, incluindo cópia, sem autorização expressa do editor.
Aviso Legal A qualidade científica e os conteúdos das comunicações são da inteira responsabilidad... more Aviso Legal A qualidade científica e os conteúdos das comunicações são da inteira responsabilidade dos respetivos autores. O editor não aceita qualquer responsabilidade pela informação contida nas comunicações inseridas na presente publicação. Nos termos legais em vigor, é expressamente proibida a reprodução total ou parcial desta publicação, no seu todo ou em parte, não podendo ser reproduzida ou transmitida por qualquer forma ou processo eletrónico, mecânico ou outros, incluindo cópia, sem autorização expressa do editor.
Tiles are found on numerous Portuguese facades. The exposure to external agents causes degradatio... more Tiles are found on numerous Portuguese facades. The exposure to external agents causes degradation and, in some cases, detachment of these tiles. In the coastal area of Aveiro city (Portugal), the building's facades, exposed to adverse atmospheric conditions are in constant contact with aggressive agents, which cause the detachment of a significant amount of facade tiles. Within the scope of the SOS Azulejo Project, and in partnership with the University of Aveiro, Fábrica Centro Ciência Viva de Aveiro, the Prison of Aveiro and DDL Arg, this study encompasses the conservation of a tile facade, after degradation and detachment of the ceramic body. Several replicas of the tiles were made in the specific context of a training action that took place at the Aveiro Prison. The technical study was carried out to analyse the compatibility and reversibility of the mortars and ceramic tiles used. The mortars were tested in their fresh and hard state for consistency through spreading, flex...
Tiles are found on numerous Portuguese facades. The exposure to external agents causes degradatio... more Tiles are found on numerous Portuguese facades. The exposure to external agents causes degradation and, in some cases, detachment of these tiles. In the coastal area of Aveiro city (Portugal), the building's facades, exposed to adverse atmospheric conditions are in constant contact with aggressive agents, which cause the detachment of a significant amount of facade tiles. Within the scope of the SOS Azulejo Project, and in partnership with the University of Aveiro, Fábrica Centro Ciência Viva de Aveiro, the Prison of Aveiro and DDL Arg, this study encompasses the conservation of a tile facade, after degradation and detachment of the ceramic body. Several replicas of the tiles were made in the specific context of a training action that took place at the Aveiro Prison. The technical study was carried out to analyse the compatibility and reversibility of the mortars and ceramic tiles used. The mortars were tested in their fresh and hard state for consistency through spreading, flex...
Metakaolins (MKs) prepared from low-grade kaolins located in the Alvarães (A) and Barqueiros (B) ... more Metakaolins (MKs) prepared from low-grade kaolins located in the Alvarães (A) and Barqueiros (B) regions of Portugal were used as the aluminosilicate source to compare their effect on the compressive strength and heavy metal adsorption of geopolymers. Natural zeolite, an inexpensive, efficient adsorbent, was used as an additive in formulations to enhance geopolymers’ adsorption capacities and reduce MK utilization’s environmental footprint. Geopolymers were synthesized with the replacement of MK by zeolite up to 75 wt.% (A25, B25—25% MK 75% zeolite; A50, B50—50% MK 50% zeolite; A75, B75—75% MK 25% zeolite; A100, B100—100% MK). The molar ratios of SiO2/Al2O3 and Na2O/Al2O3 were kept at 1 to reduce the sodium silicate and sodium hydroxide environmental impact. Geopolymers’ crystallography was identified using X-ray diffraction analysis. The surface morphology was observed by scanning electron microscopy to understand the effect of zeolite incorporation. Chemical analysis using X-ray f...
Metakaolins (MKs) prepared from low-grade kaolins located in the Alvarães (A) and Barqueiros (B) ... more Metakaolins (MKs) prepared from low-grade kaolins located in the Alvarães (A) and Barqueiros (B) regions of Portugal were used as the aluminosilicate source to compare their effect on the compressive strength and heavy metal adsorption of geopolymers. Natural zeolite, an inexpensive, efficient adsorbent, was used as an additive in formulations to enhance geopolymers’ adsorption capacities and reduce MK utilization’s environmental footprint. Geopolymers were synthesized with the replacement of MK by zeolite up to 75 wt.% (A25, B25—25% MK 75% zeolite; A50, B50—50% MK 50% zeolite; A75, B75—75% MK 25% zeolite; A100, B100—100% MK). The molar ratios of SiO2/Al2O3 and Na2O/Al2O3 were kept at 1 to reduce the sodium silicate and sodium hydroxide environmental impact. Geopolymers’ crystallography was identified using X-ray diffraction analysis. The surface morphology was observed by scanning electron microscopy to understand the effect of zeolite incorporation. Chemical analysis using X-ray f...
Geodesign project is a co-promotion project funded by the Portugal 2020 program with the aim of d... more Geodesign project is a co-promotion project funded by the Portugal 2020 program with the aim of developing new architectural products, integrating industrial waste and by-products generated by Portuguese companies, namely in the fields of steel, smelting, power stations, metallurgy and glassmaking. The partners of the project are W2V, SA, dedicated to waste management activities, Providência Design, dedicated to product design, the CVR technology center and the Portuguese universities of Minho and Trás-os-Montes and Alto Douro. Fly ash from thermoelectric plants, aluminum anodizing sludge and glass polishing dusts, among others, offer different plastic and chromatic qualities. When chemically integrated in the form of geopolymers or calcium-based materials, they exhibit different physical qualities of mechanical strength and aging. Taking into account their physical qualities and, consequently, the diversity of chromatic, textural and economical results, several functional products ...
The authors wish to acknowledge the Foundation for Science and Technology (FCT) for the financial... more The authors wish to acknowledge the Foundation for Science and Technology (FCT) for the financial support under project EXREACT (PTDC/CTM/65243/2006) and project DURATINET (Durable Transport Infrastructures in the Atlantic Area Network) for Transnational Programme Atlantic Area 2007-2003, co-financed by FEDER.
Portugal is one of the European countries in which built heritage is a testimony of its history. ... more Portugal is one of the European countries in which built heritage is a testimony of its history. In this context, the legacy of the decorative glazed tile coatings of facades must be preserved and restored. This research is dedicated to the conservation of such facades in the city of Ovar, considered an example due to its rich heritage in glazed tiles, a high percentage of which requires a deep intervention. Therefore, this work is focused on the study of lime renders serving as a support for this type of tile facades. For this, samples were collected from several buildings in the city, targeting their mechanical and physical study with the aim of producing compatible mortars to be used for application of detached tiles in these buildings and generally for the repair of the facades with glazed tile coatings. For this purpose, four lime mortar formulations with different volumetric ratios were composed. The aggregates used were: ordinary river sand and local gravel. In three of the mixtures, metakaolin was added, with the intention of acting as an artificial pozzolan and thus improving the performance of these mortars. The use of a pozzolanic addition promotes hardening of lime mortars in cases when the ingression of carbon dioxide is low as is the case of mortars placed below glazed tile coatings. These mortars were also tested in the laboratory taking into account their physical and mechanical characteristics. The mechanical characteristics determined were: modulus of elasticity by two different methods, compressive strength and flexural strength. In turn, the physical characteristics determined were: water vapour permeability and water absorption by total immersion and capillary action. The best mechanical behaviour (compressive and flexural) was observed in the mortar with pozzolanic additions. Similarly, the value of the modulus of elasticity was better in mortars with pozzolanic additions. The performance of these mortars was also adequate in terms of water behaviour. The mortars revealed suitable characteristics for application in building conservation situations concerning coating with glazed tiles. Keywords Conservation; glazed tiles; lime mortars; pozzolanic additions. Resumo Portugal é um dos países europeus em que o património construído é um testemunho da sua história. Neste contexto, o legado relativo aos azulejos de revestimento de fachada necessita de ser preservado. A investigação desenvolvida foi dedicada à conservação destas fachadas na cidade de Ovar, considerada exemplar devido à riqueza do seu património azulejar, do qual uma percentagem considerável necessita de acções de intervenção profundas. Por este motivo, o trabalho desenvolvido focou-se no estudo das argamassas de assentamento para este tipo de fachadas. De forma a permitir o estudo das argamassas antigas, foram retiradas várias amostras de argamassa de diversos edifícios da cidade. Estas amostras foram ensaiadas para determinar as suas características físicas e mecânicas com o objectivo de produzir argamassas compatíveis, passíveis de aplicação em casos de destacamento dos revestimentos azulejares nestes edifícios e, de uma forma geral, em fachadas azulejadas. Com este objectivo, quatro formulações de argamassas de cal, com diferentes traços volumétricos, foram efectuadas. Os agregados utilizados foram areia de rio siliciosa e uma areia local (saibro). Em três destas composições foi adicionado metacaulino, para que actuasse como uma pozolana artificial, melhorando o desempenho destas argamassas. A utilização de adições pozolânicas promove o endurecimento de argamassas de cal nos casos em que o ingresso de dióxido de carbono é baixo como é o caso de argamassas de assentamento localizadas sob uma camada de azulejo. Relativamente a estas argamassas, foram efectuados ensaios laboratoriais para testar as suas características físicas e mecânicas. Como características mecânicas, foi determinado o módulo de elasticidade utilizando duas metodologias diferentes, assim como a resistência à flexão e compressão. A determinação de características físicas incidiu na determinação da permeabilidade ao vapor de água, na absorção de água por imersão e na absorção de água por capilaridade. Verificou-se uma melhoria do comportamento mecânico (resistência à flexão e compressão) de argamassas com adição de pozolana. De forma similar verificou-se um valor mais elevado para o módulo de elasticidade destas argamassas. O comportamento destas argamassas relativamente à absorção de água revelou-se adequado. As argamassas testadas revelaram características apropriadas para a aplicação na conservação de edifícios no caso de utilização como argamassas de assentamento para revestimentos azulejares. Palavras-chave Conservação; azulejos; argamassas de cal; adições pozolânicas.
The durability of concrete structures is an important issue nowadays. Specifically in the case of... more The durability of concrete structures is an important issue nowadays. Specifically in the case of reinforced concrete bridges or other infrastructures one of the main form of environmental attack is the penetration of chloride ions, which leads to corrosion of concrete steel reinforcement. This study aims to evaluate the effect of the introduction of metakaolin and diatomite, two chemically and physically different pozzolans, on the resistance of concrete to the penetration of chlorides but also the effect on other properties of concrete, namely, its compressive strength and its porosity distribution. The results of this study show that the pozzolans physical and chemical characteristics have a strong influence on the pozzolans behavior and, consequently, on the concrete properties.
This research was focused on the use of the modified Chapelle test as a direct laboratory methodo... more This research was focused on the use of the modified Chapelle test as a direct laboratory methodology to access the pozzolanic activity of both experimental and commercial metakaolins. At the same time, this test was used in the evaluation of experimental metakaolins. This chemical test, performed during 16 hours at 90 °C, allows the quantification of portlandite fixed by the metakaolin sample. The calcium hydroxide that was not consumed is quantified by acid titration (HCl), and the test result is expressed in mg of fixed calcium hydroxide by g of metakaolin. According to this test, the pozzolanic activity of a metakaolin should not be less than 700 mg Ca(OH) 2 / g metakaolin. The modified Chapelle pozzolanic activity of six commercial metakaolins was evaluated between 920 and 1560 mg Ca(OH) 2 / g metakaolin. From the seven experimental metakaolins produced between 750 ºC and 940 ºC, a material with modified Chapelle pozzolanic activity value of 1240 mg Ca(OH) 2 / g metakaolin was obtained, which is similar to some tested commercial metakaolins produced at industrial scale. The metakaolin produced at 800 ºC was ground, resulting in a particle size reduction of ≈ 4x less and a consequent increase of 21 % in the pozzolanic activity.
The aim of this project is the development of new architectural products, integrating industrial ... more The aim of this project is the development of new architectural products, integrating industrial waste of class C and F, generated by companies based in the North of Portugal, namely in the fields of foundry, glass and paper. This selection results from technical consulting from “Waste to Value” assisted by the contribution of scientific research in geopolymers of the laboratory of the University of Minho, consultancy of the University of Trás-os-Montes and evaluation of resistance by the Materials laboratory of the University of Aveiro. The flying ash from thermoelectric plants, sludge from aluminium anodizing and glass polishing among others, offers different plastic and chromatic qualities. When chemically integrated by geopolymerization, they exhibit different physical qualities of strength, resistance to use and aging. Taking into consideration their physical qualities and, consequently, the resulting chromatic, textural and economic diversity, several functional products of wa...
Caracterização da interface azulejo/argamassa de fachadas históricas 55 Caracterização da interfa... more Caracterização da interface azulejo/argamassa de fachadas históricas 55 Caracterização da interface azulejo/argamassa de fachadas históricas
With the availability of commercial Natural cements (NC) for the conservation purposes raises a f... more With the availability of commercial Natural cements (NC) for the conservation purposes raises a fundamental question about the compatibility between historic and repair mortars. The properties of Natural cements are dependent on the geological location of the raw material extraction and also on the production parameters, both having an impact on the final properties of the mortars produced from each distinct. Therefore, the significance of preservation of 19th and 20th century heritage and selection of the proper binder compatible with the original materials necessitate the study of existing NCs, that nowadays are produced by several manufacturers. This work provides a complex study of the mortars prepared from three NCs available in the market: Groupe Prompt Vicat, France (NCPV); Cemento Collet Marfil (NCM) and Cemento Natural Tigre (NCT), both from Spain. Various mortar sets based on individual NC containing different binder/aggregate ratios and air lime additions were analyzed af...
With the availability of commercial Natural cements (NC) for the conservation purposes raises a f... more With the availability of commercial Natural cements (NC) for the conservation purposes raises a fundamental question about the compatibility between historic and repair mortars. The properties of Natural cements are dependent on the geological location of the raw material extraction and also on the production parameters, both having an impact on the final properties of the mortars produced from each distinct. Therefore, the significance of preservation of 19th and 20th century heritage and selection of the proper binder compatible with the original materials necessitate the study of existing NCs, that nowadays are produced by several manufacturers. This work provides a complex study of the mortars prepared from three NCs available in the market: Groupe Prompt Vicat, France (NCPV); Cemento Collet Marfil (NCM) and Cemento Natural Tigre (NCT), both from Spain. Various mortar sets based on individual NC containing different binder/aggregate ratios and air lime additions were analyzed af...
Aviso Legal A qualidade científica e os conteúdos das comunicações são da inteira responsabilidad... more Aviso Legal A qualidade científica e os conteúdos das comunicações são da inteira responsabilidade dos respetivos autores. O editor não aceita qualquer responsabilidade pela informação contida nas comunicações inseridas na presente publicação. Nos termos legais em vigor, é expressamente proibida a reprodução total ou parcial desta publicação, no seu todo ou em parte, não podendo ser reproduzida ou transmitida por qualquer forma ou processo eletrónico, mecânico ou outros, incluindo cópia, sem autorização expressa do editor.
Aviso Legal A qualidade científica e os conteúdos das comunicações são da inteira responsabilidad... more Aviso Legal A qualidade científica e os conteúdos das comunicações são da inteira responsabilidade dos respetivos autores. O editor não aceita qualquer responsabilidade pela informação contida nas comunicações inseridas na presente publicação. Nos termos legais em vigor, é expressamente proibida a reprodução total ou parcial desta publicação, no seu todo ou em parte, não podendo ser reproduzida ou transmitida por qualquer forma ou processo eletrónico, mecânico ou outros, incluindo cópia, sem autorização expressa do editor.
Tiles are found on numerous Portuguese facades. The exposure to external agents causes degradatio... more Tiles are found on numerous Portuguese facades. The exposure to external agents causes degradation and, in some cases, detachment of these tiles. In the coastal area of Aveiro city (Portugal), the building's facades, exposed to adverse atmospheric conditions are in constant contact with aggressive agents, which cause the detachment of a significant amount of facade tiles. Within the scope of the SOS Azulejo Project, and in partnership with the University of Aveiro, Fábrica Centro Ciência Viva de Aveiro, the Prison of Aveiro and DDL Arg, this study encompasses the conservation of a tile facade, after degradation and detachment of the ceramic body. Several replicas of the tiles were made in the specific context of a training action that took place at the Aveiro Prison. The technical study was carried out to analyse the compatibility and reversibility of the mortars and ceramic tiles used. The mortars were tested in their fresh and hard state for consistency through spreading, flex...
Tiles are found on numerous Portuguese facades. The exposure to external agents causes degradatio... more Tiles are found on numerous Portuguese facades. The exposure to external agents causes degradation and, in some cases, detachment of these tiles. In the coastal area of Aveiro city (Portugal), the building's facades, exposed to adverse atmospheric conditions are in constant contact with aggressive agents, which cause the detachment of a significant amount of facade tiles. Within the scope of the SOS Azulejo Project, and in partnership with the University of Aveiro, Fábrica Centro Ciência Viva de Aveiro, the Prison of Aveiro and DDL Arg, this study encompasses the conservation of a tile facade, after degradation and detachment of the ceramic body. Several replicas of the tiles were made in the specific context of a training action that took place at the Aveiro Prison. The technical study was carried out to analyse the compatibility and reversibility of the mortars and ceramic tiles used. The mortars were tested in their fresh and hard state for consistency through spreading, flex...
Metakaolins (MKs) prepared from low-grade kaolins located in the Alvarães (A) and Barqueiros (B) ... more Metakaolins (MKs) prepared from low-grade kaolins located in the Alvarães (A) and Barqueiros (B) regions of Portugal were used as the aluminosilicate source to compare their effect on the compressive strength and heavy metal adsorption of geopolymers. Natural zeolite, an inexpensive, efficient adsorbent, was used as an additive in formulations to enhance geopolymers’ adsorption capacities and reduce MK utilization’s environmental footprint. Geopolymers were synthesized with the replacement of MK by zeolite up to 75 wt.% (A25, B25—25% MK 75% zeolite; A50, B50—50% MK 50% zeolite; A75, B75—75% MK 25% zeolite; A100, B100—100% MK). The molar ratios of SiO2/Al2O3 and Na2O/Al2O3 were kept at 1 to reduce the sodium silicate and sodium hydroxide environmental impact. Geopolymers’ crystallography was identified using X-ray diffraction analysis. The surface morphology was observed by scanning electron microscopy to understand the effect of zeolite incorporation. Chemical analysis using X-ray f...
Metakaolins (MKs) prepared from low-grade kaolins located in the Alvarães (A) and Barqueiros (B) ... more Metakaolins (MKs) prepared from low-grade kaolins located in the Alvarães (A) and Barqueiros (B) regions of Portugal were used as the aluminosilicate source to compare their effect on the compressive strength and heavy metal adsorption of geopolymers. Natural zeolite, an inexpensive, efficient adsorbent, was used as an additive in formulations to enhance geopolymers’ adsorption capacities and reduce MK utilization’s environmental footprint. Geopolymers were synthesized with the replacement of MK by zeolite up to 75 wt.% (A25, B25—25% MK 75% zeolite; A50, B50—50% MK 50% zeolite; A75, B75—75% MK 25% zeolite; A100, B100—100% MK). The molar ratios of SiO2/Al2O3 and Na2O/Al2O3 were kept at 1 to reduce the sodium silicate and sodium hydroxide environmental impact. Geopolymers’ crystallography was identified using X-ray diffraction analysis. The surface morphology was observed by scanning electron microscopy to understand the effect of zeolite incorporation. Chemical analysis using X-ray f...
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