Добірка наукової літератури з теми "Geopolymer mortars"
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "Geopolymer mortars".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Статті в журналах з теми "Geopolymer mortars"
1
Asprogerakas, A., Aristea Koutelia, Glykeria Kakali, and Sotirios Tsivilis. "Durability of Fly Ash Geopolymer Mortars in Corrosive Environments, Compared to that of Cement Mortars." Advances in Science and Technology 92 (October 2014): 84–89. http://dx.doi.org/10.4028/www.scientific.net/ast.92.84.
Повний текст джерелаАнотація:
In the present paper the durability of fly ash geopolymer mortars compared to that of cement mortars is investigated. Geopolymers can improve the ecological image of building materials, especially when their production is based on industrial by-products such as fly ash. Three series of fly ash based geopolymer mortars were prepared using calcareous sand to fly ash ratio (S/FA) varying from 0.5 to 2. In addition, cement mortar specimens were prepared using cement CEM I 42.5 N and CEM II 32.5 N. Durability of geopolymer and cement mortars was evaluated by means of compressive strength development, acid resistance, chloride diffusion and sulfate resistance. It was found that fly ash can be effectively used to produce geopolymer mortars with calcareous sand. Geopolymers exhibit competitive compressive strength compared to that of cement mortars. Geopolymer mortars develop their maximum compressive strength a few days after their casting. Geopolymer and cement mortars exhibit satisfactory resistance to sulphate attack. Cement mortars, generally, show better behaviour (compared to geopolymers) in chloride diffusion. Finally, geopolymers indicate improved performance against acid attack, compared to that of cement mortars.
2
Belmokhtar, Noureddine, Ikram Frar, Mohammed Ammari, and Laïla Ben Allal. "The Behavior of Geopolymer Mortars Based on Industrial Sludge Exposed to Aggressive Mediums." Journal of Solid Waste Technology and Management 48, no. 2 (May 1, 2022): 313–23. http://dx.doi.org/10.5276/jswtm/2022.313.
Повний текст джерелаАнотація:
There is a growing interest in geopolymer materials. One of its advantages is the possibility of reusing a wide range of industrial waste. This paper aims to study the effect of the molar ratio H2O/Na2O(t) on the physical, chemical, and mechanical properties of industrial slurry-based geopolymers mortars and to evaluate the behavior of the synthesized mortar, which has the shortest setting time, in aggressive mediums. Structural changes in geopolymer mortars were monitored by X-ray diffraction (XRD) and Raman spectroscopy. The morphology of the samples was monitored by the Scanning Electron Microscope (SEM). SEM micrographs of geopolymer mortars show an intimate bond between sand grains and geopolymer cement. The compressive strength of geopolymer mortars varies significantly with the molar ratio H2O/Na2O(t). The mass loss of geopolymer mortars immersed in hydrochloric acid and sulfuric acid is more than that immersed in other solutions but lower than that of Portland cement-based mortars immersed in the same solutions.
3
Istuque, D., L. Soriano, M. V. Borrachero, J. Payá, J. L. Akasaki, J. L. P. Melges, and M. M. Tashima. "Evaluation of the long-term compressive strength development of the sewage sludge ash/metakaolin-based geopolymer." Materiales de Construcción 71, no. 343 (July 30, 2021): e254. http://dx.doi.org/10.3989/mc.2021.13220.
Повний текст джерелаАнотація:
This paper aimed to evaluate the long-term compressive strength development of the sewage sludge ash/metakaolin (SSA/MK)-based geopolymer. SSA/MK-based geopolymeric mortars and pastes were produced at 25ºC with different SSA contents (0 - 30 wt.%). Compressive strength tests were run within the 3-720 curing days range. A physicochemical characterisation (X-ray diffraction and scanning electron microscopy) was performed in geopolymeric pastes. All the geopolymeric mortars presented a compressive strength gain with curing time. The mortars with all the SSA evaluated contents (10, 20, 30 wt.%) developed a compressive strength over 40 MPa after 720 curing days at 25ºC. The maximum compressive strength of the mortars with SSA was approximately 61 MPa (10 wt.% of SSA), similarly to the reference mortar (100% MK-based geopolymer). The microstructure analyses showed that the SSA/MK-based geopolymer presented a dense microstructure with N-A-S-H gel formation.
4
Kawalu, Ndapandula, Abdolhossein Naghizadeh, and Jeffrey Mahachi. "The effect of glass waste as an aggregate on the compressive strength and durability of fly ash-based geopolymer mortar." MATEC Web of Conferences 361 (2022): 05007. http://dx.doi.org/10.1051/matecconf/202236105007.
Повний текст джерелаАнотація:
Geopolymers have been introduced to limit the use of ordinary Portland cement (OPC), as its production contributes to the emission of about 7% of the world’s carbon dioxide, which has a negative effect on the environment. The present study aimed to investigate the effect of glass-waste aggregate on the mechanical properties of fly ash-based geopolymer and OPC mortars. In the study, fly ash geopolymer and OPC mortar mixtures were prepared using glass-waste as fine aggregate. In addition, geopolymer and OPC mortars were also prepared using silica sand as control mixes. A blended solution comprising sodium silicate and sodium hydroxide was used as an alkali activator in fly ash geopolymer mixtures. Fresh mixtures were subjected to workability measurements, while 50 mm cubes were made for compressive strength testing. Mortar prisms of 25 x 25 x 285 mm were prepared and subjected to drying shrinkage test. From the results, the use of glass-waste aggregate negatively affected the compressive strength of the mortars, regardless of the binder type. Geopolymer mortars made using glass-waste aggregate gave 55% lower compressive strength than those made using silica sand. However, mixtures made using glass waste aggregate exhibited better performance in drying shrinkage than those made using silica sand.
5
Samadhi, Tjokorde Walmiki, Pambudi Pajar Pratama, and Nurhidayati Muan. "Development of Geopolymer Utilizing Inorganic Waste Materials." Advanced Materials Research 896 (February 2014): 553–56. http://dx.doi.org/10.4028/www.scientific.net/amr.896.553.
Повний текст джерелаАнотація:
Geopolymers, which are produced by the reaction between aluminosilicate solid precursors and concentrated alkali solutions, is an environmentally attractive construction material due to its much smaller carbon footprint compared to ordinary Portland cement (OPC), and its ability to consume a wide range of solid inorganic waste materials. This work describes the synthesis of geopolymers utilizing local aluminosilicate materials and the evaluation of several key engineering properties of the geopolymer product as a construction cement. A simple 22factorial experiment is undertaken to measure the effect of types aluminosilicate solids (metakaolin produced by calcining a Belitung kaolin at 750 °C, and coal fly ash from an East Java baseload powerplant) and alkali activators (NaOH and KOH solutions) on the initial and final setting time of the geopolymer cement mortar. All geopolymer mortar samples exhibit longer setting times compared to OPC mortars. Statistical analysis indicates that KOH produces faster initial setting than NaOH, while fly ash produces faster setting times compared to metakaolin. A 23factorial experiment is conducted subsequently, adding curing temperature (60 and 80 °C) to the experimental factors. The key engineering property measured in the second experiment is the compressive strength of geopolymer mortars. ANOVA treatment of the measured data indicates that all three experimental factors significantly impacts the compressive strength. Consistent with the preceding experiment, the use of fly ash and KOH significantly increases the strength of the geopolymer mortar. Higher curing temperature is also found to increase the strength. The use of metakaolin as geopolymer precursor produces compressive strength approximately 50% than that of the OPC mortar, while fly ash produces a geopolymer mortar strength that is at least as good as OPC.
6
Vasconcelos, Eduardo, Sérgio Fernandes, Barroso de Aguiar, and F. Pacheco-Torgal. "Concrete Retrofitting Using CFRP and Geopolymer Mortars." Materials Science Forum 730-732 (November 2012): 427–32. http://dx.doi.org/10.4028/www.scientific.net/msf.730-732.427.
Повний текст джерелаАнотація:
A new development in the repair and strengthening of reinforced concrete systems is the use of carbon fiber reinforced polymers (CFRP) strips bonded to concrete substrate with epoxy resins. It has been reported that epoxy adhesive are extremely sensitive to high temperatures. Some authors conclude that the epoxy temperature should not exceed 70 °C in order to safeguard the adhesiveness of the epoxy and, thus, the integrity and adequate functioning of CFRP. It is noted that even frequently exposure to direct sunlight causes temperatures higher than 70 °C. Since geopolymers are known to possess high stability at high temperature, these materials can be an alternative to epoxy resins. This papers presents results about the use of metakaolin based geopolymers mortars to insure the adhesion between the CFRP and the concrete substrate. Several compositions of geopolymer mortars were executed by varying the percentage of binder, sand/binder ratio and the concentration of sodium hydroxide. It was found that geopolymer mortars demonstrate very promising performances, having obtained a high mechanical resistance and a good adhesion to concrete. On the other hand the adhesion between CFRP and geopolymer mortars proved to be smaller than expected which could be due, to the fact that the composition of the mortar was not optimized or even to the nature of the CFRP.
7
Pareek, Sanjay, Hiroo Kashima, Ippei Maruyama, and Yoshikazu Araki. "Adhesion characteristics of geopolymer mortar to concrete and rebars." MATEC Web of Conferences 258 (2019): 01012. http://dx.doi.org/10.1051/matecconf/201925801012.
Повний текст джерелаАнотація:
In recent years, geopolymers have gained a wide attention as highly ecological-friendly building materials, having a capability to cut down 70% of CO2 emissions in comparison to the ordinary cement concrete. In this study, geopolymer mortars are proposed as repair materials for reinforced concrete structures, due to their superior acid resistance, heat resistance and high strength in comparison to the existing repair materials. The objective of this study is to investigate the adhesion properties of geopolymer mortars to concrete substrates with different surface treatments, steel plates and rebars. As a result, the geopolymer mortars are found to have excellent adhesion properties to dry concrete substrates, steel plates and rebars. Concrete substrates treated with grinder, further enhanced the adhesion properties of geopolymer mortars. On the other hand, poor adhesion of geopolymer mortars to wet concrete substrates was observed due to the presence of water on the interfacial zone, which decreased the alkali concentration of the geopolymer, resulting in lower adhesion strength. In general, geopolymer mortars are found to have suitable adhesion properties to the concrete substrates, steel plates and rebars and can be applied as repair materials for reinforced concrete structures.
8
Schwaab, S., O. K. Ueno, D. Ganasini, M. V. Folgueras, and Sivaldo L. Correia. "Physical Properties, Mechanical Strength and Microstructure of Fired Clay Brick Waste and Metakaolin Geopolymer Mortars." Materials Science Forum 930 (September 2018): 170–75. http://dx.doi.org/10.4028/www.scientific.net/msf.930.170.
Повний текст джерелаАнотація:
This paper presents a study related to the application of geopolymers cements as a binder on production of mortars for construction and building materials. Geopolymeric cements were produced from metakaolin, clay brick waste and activator consisting of potassium hydroxide and potassium silicate. The mixtures were prepared using standard production processes according Brazilian standards. Hardened properties of density, water absorption, 7-day and 28-day compressive strength were evaluated on samples of cured mortars. Selected samples of fractured specimens were subjected to microstructural characterisation via scanning electron microscopy, X-ray diffraction and thermal analysis. The results for the 7-day and 28-day compressive strength of geopolymer mortars showed that these materials have properties as good as those obtained from Portland cement mortars. Microstructural characterization of fractured pieces showed a morphology usually found in the category of geopolymers product structures.
9
Bringas-Rodríguez, V. C., G. P. Rodríguez-Guillén, F. A. Cuzziramos-Gutiérrez, D. L. Mayta-Ponce, and F. A. Huamán-Mamani. "Study of Mechanical Behavior of Geopolymeric Mortars Reinforced with Ichu Fibers." Key Engineering Materials 931 (September 9, 2022): 167–74. http://dx.doi.org/10.4028/p-0570co.
Повний текст джерелаАнотація:
Reinforced geopolymeric mortars were manufactured by mixing mining tailings, fine sand, Ichu fibers (in variable percentages), sodium hydroxide and water. The microstructure of the obtained mortars consisted of a continuous geopolymer binder phase with sand particles and Ichu fibers dispersed within the binder phase. The real density and average porosity of the reinforced mortars was 2.74 g/cm3 and 34%, respectively. It was possible to verify the influence of the addition of Ichu fibers on the mechanical response in uniaxial compression of the studied mortars, due to the poor interface between the geopolymer and the fibers. The mechanical results revealed a systematic reduction of the maximum compressive strength when the volume of Ichu fibers in the mortar mixtures was increased. On the other hand, a higher degree of deformation was evidenced in mortar mixtures containing a greater amount of Ichu fibers, reaching deformation values of up to 5%. The maximum resistance values found were from 2.87 to 20.76 MPa for samples with 8 and 0 vol.% of Ichu fibers added, respectively.
10
Aziz, Mohamad Abdul Zahari, A. Z. Norzeity, I. Johari, and Shah Rizal Kasim. "Effect of Adding Hydrogen Peroxide (H<sub>2</sub>O<sub>2</sub>) and Sodium Dodecyl Sulphate (SDS) to the Properties of Fly Ash (FA)-Based Geopolymer Mortar." Key Engineering Materials 908 (January 28, 2022): 658–63. http://dx.doi.org/10.4028/p-b9umsp.
Повний текст джерелаАнотація:
Geopolymer is an alternative cementitious material produced by rich aluminosilicate mineral materials (Si-Al) combine with an alkaline activator. The objectives of this study are to study the effect of adding hydrogen peroxide (H2O2) and sodium dodecyl sulphate (SDS) as foaming and stabilizing agents, respectively to the fly ash (FA)-based geopolymer mortar properties. The geopolymer mortars were synthesized with a mixture of FA, alkaline activator and SDS with different H2O2 content. The geopolymer mortars were analyzed using compressive strength test, porosity test and Scanning Electron Microscopy (SEM) analysis. Geopolymer mortar with 1 wt% H2O2 content and 0.5 wt% SDS has the lowest compressive strength (8.67 N) compare to the other geopolymer mortar composition. As H2O2 content increase with presence of SDS, the formation of the pores also increased hence resulting in the low compressive strength of geopolymer mortar.
Дисертації з теми "Geopolymer mortars"
1
Ávila, Tainara Cristina. "Estudo da utilização da mistura de cinza da casca de arroz com hidróxido de sódio na produção de argamassas ativadas alcalinamente /." Ilha Solteira, 2018. http://hdl.handle.net/11449/180872.
Повний текст джерелаАнотація:
Orientador: José Luiz Pinheiro MelgesResumo: Atualmente, é vasta a quantidade de materiais estudados com potencial de substituir o cimento Portland em matrizes cimentícias, uma vez que a produção do mesmo é responsável pela emissão de grande quantidade de CO2, o que contribui drasticamente para o efeito estufa. Nesse contexto, os aglomerantes ativados alcalinamente são materiais que prometem qualidades similares ou superiores àqueles à base de cimento, porém produzidos com elementos menos agressivos ao meio ambiente. Neste trabalho, é realizado o estudo da aplicação de Cinza da Casca de Arroz (CCA) com Hidróxido de Sódio (NaOH) na produção de solução alcalina, para ativação do metacaulim, material este que já possui resultados positivos quando ativado com silicato de sódio, e outros ativadores obtidos comercialmente. A solução de CCA-NaOH é utilizada como substituta do silicato de sódio comercial, uma vez que, além de utilizar um resíduo em sua produção, dando a ele uma destinação adequada, observa-se uma significativa economia de energia, já que a produção de silicato de sódio demanda uma grande quantidade de energia para sua obtenção. Para que a solução de CCA-NaOH apresente potencial de ativar o metacaulim, é necessário manter tais materiais, por 24h em meio térmico, para que ocorra a dissolução da sílica do CCA. Utilizando-se a composição CCA-NaOH, foram elaborados 5 traços de argamassa com relações molares SiO2/NaOH iguais a 0.0; 0.4; 0.8; 1.2 e 1.6. Também foram elaborados outros 5 traços com as mesmas relações mo... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: Nowadays, the amount of studied materials with the potential to replace Portland cement in cementitious matrices is extensive, since its production is responsible for the emission of a large amount of CO2, which contributes drastically to the greenhouse effect. In this context, alkali-activated binders are materials that promise qualities similar or superior to those based on cement, but produced with elements that are less aggressive to the environment. In this work, Rice Husk Ash (RHA) with sodium hydroxide (NaOH) are used to produce an alkaline solution for the activation of metakaolin, which has already positive results when activated with sodium silicate or others commercially available activators. The RHA-NaOH solution is used as a substitute for commercial sodium silicate, once in addition to use a residue in its production, giving it an adequate disposal, it works with the fact of saving energy, since the production of silicate of sodium consumes a large amount of energy for its obtainment. In order for the RHA-NaOH solution to have the potential to activate metakaolin, it is necessary to keep such materials for 24 hours in a thermal container in order to dissolve the silica from the CCA. Using the RHA-NaOH solution, 5 mixtures of mortar were prepared with SiO2 / NaOH molar ratios equal to 0.0; 0.4, 0.8, 1.2 and 1.6. Another 5 mixtures were prepared with the same molar ratios, but this time using commercial sodium silicate for comparison purposes. It was observed the ... (Complete abstract click electronic access below)
Mestre
2
Photisan, Methawee Sriwattanapong [Verfasser]. "Influence of Calcium Aluminate Cement and Ground Granulated Blast Furnace Slag on the Synthesis of Rice Husk Ash-Based Geopolymer Mortars / Methawee Sriwattanapong Photisan." Kassel : Universitätsbibliothek Kassel, 2018. http://d-nb.info/1155438795/34.
Повний текст джерела
3
Santos, Gessica Zila Batista dos. "Argamassa geopolimérica à base de lodo de estação de tratamento de água calcinado." Universidade Federal do Amazonas, 2016. http://tede.ufam.edu.br/handle/tede/5532.
Повний текст джерелаАнотація:
Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-02-22T13:30:44Z
No. of bitstreams: 2
license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)
Dissertação - Géssica Batista.pdf: 4335597 bytes, checksum: 62909b0c2d9fe397881952f9f2118d70 (MD5)Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-02-22T13:31:01Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Géssica Batista.pdf: 4335597 bytes, checksum: 62909b0c2d9fe397881952f9f2118d70 (MD5)
Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2017-02-22T13:31:20Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Géssica Batista.pdf: 4335597 bytes, checksum: 62909b0c2d9fe397881952f9f2118d70 (MD5)
Made available in DSpace on 2017-02-22T13:31:21Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertação - Géssica Batista.pdf: 4335597 bytes, checksum: 62909b0c2d9fe397881952f9f2118d70 (MD5) Previous issue date: 2016-12-12
CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
In the process of water treatment for public supply, which is made in the water treatment plants (WTPs), a waste conventionally called sludge is formed. As in the soil, the main components of WTP sludge are silicon (Si), aluminum (Al) and iron (Fe). This composition allowed to suggest that this waste could be used in the production of inorganic polymers - the geopolymers. While conventional polymers are formed by carbon structures, geopolymers are composed of Si and Al structures. They are obtained by dissolving aluminosilicates materials in highly alkaline solution. Among the possible applications, they can be used as pastes, mortars and concretes, in replacement of Portland cement, which is the most used binder in civil construction worldwide. To verify the suitability of the sludge as a geopolymer precursor, this waste was properly benefited by means of mechanical grinding and calcination at 750 °C for 6 hours, being characterized before and after its processing. The results of chemical and mineralogical analyzes proved the adequacy of calcined WTP sludge as a geopolymeric raw material. To check the influence of the sources of raw water abstraction intake on the WTP sludge characteristics and consequently in the properties of materials produced from sludge-based, samples of this waste were collected under the influence of two different water sources. With these samples it produced of two geopolymeric mortars. The final products were properly characterized and the results proved that regardless of the peculiarities of water sources, WTP sludge can be used as a geopolymeric raw material. In the thermal tests the two mortars produced showed indications of refractory bahavior and have been free of calcium hydroxide, therefore, it can be inferred that they are free matrices of deleterious actions of this compound. In the mechanical tests, at 28 days of cure, they reached mechanical strengths of 57 and 79 MPa, on average. Some results evidenced the need for improvements in the formulation of mortars, but in general, it was verified that the use of WTP sludge as a geopolymer precursor material is a very promising alternative for the destination of this waste, making it valuable and useful product for society.
No processo de tratamento de água para abastecimento público, realizado em estações de tratamento de água – ETAs, gera-se um resíduo convencionalmente chamado de lodo. Da mesma forma que acontece no solo, os principais constituintes do lodo de ETA são o silício (Si), o alumínio (Al) e o ferro (Fe). Tal composição permitiu sugerir que este resíduo poderia ser usado na produção de polímeros inorgânicos – os geopolímeros. Enquanto os polímeros convencionais são formados por estruturas de carbono, geopolímeros são constituídos de estruturas de Si e Al. São obtidos através da dissolução de materiais aluminossilicatos em solução altamente alcalina. Dentre as possíveis aplicações, podem ser empregados como pastas, argamassas e concretos, em substituição ao cimento Portland, o material ligante mais utilizado mundialmente na construção civil. Para verificar a adequação do lodo de ETA como material precursor geopolimérico, este resíduo foi devidamente beneficiado por meio de moagem mecânica e calcinação a 750 ° C por 6 horas, sendo caracterizado antes e após seu beneficiamento. Os resultados de análises químicas e mineralógicas comprovarem a adequação do lodo de ETA calcinado como matéria-prima geopolimérica. A fim de avaliar a influência dos mananciais de captação de água bruta nas características do lodo de ETA e, consequentemente, nas propriedades de materiais produzidos à base deste resíduo, foram coletadas amostras de lodo sob influência de dois diferentes mananciais. Com estas amostras produziu-se duas argamassas geopoliméricas. Os produtos finais foram devidamente caracterizados e os resultados comprovaram que, independentemente das peculiaridades dos mananciais, o lodo de ETA pode ser utilizado como material precursor geopolimérico. Nos ensaios térmicos, as duas argamassas produzidas exibiram indícios de comportamento refratário e se mostraram isentas de hidróxido de cálcio, portanto, pode-se inferir que são matrizes livres das ações deletérias ocasionadas por este composto. Nos ensaios de resistência mecânica, aos 28 dias de cura, atingiram 57 e 79 MPa, em média. Alguns resultados evidenciaram a necessidade de melhorias na formulação das argamassas, mas de uma forma geral, constatou-se que o aproveitamento do lodo de ETA como matéria-prima geopolimérica é uma alternativa bastante promissora para a destinação deste resíduo, podendo torná-lo um produto com valor agregado e útil para a sociedade.
4
Shadnia, Rasoul, and Rasoul Shadnia. "Green Geopolymer with Incorporated PCM for Energy Saving in Buildings." Diss., The University of Arizona, 2016. http://hdl.handle.net/10150/622931.
Повний текст джерелаАнотація:
This research studies the green geopolymer incorporated with phase change material (PCM) for energy saving in buildings. First class F fly ash (FA) based-geopolymer binder was studied. In order to improve the mechanical properties, low calcium slag (SG) was added to the FA to produce geopolymer. The effect of different factors including SG content (at different relative amounts FA/SG = 0/100, 25/75, 50/50, 75/25 and 100/0), NaOH solution at different concentrations (7.5, 10 and 15 M), various curing times (1, 2, 4, 7, 14 and 28 days) and curing temperatures (25 (ambient), 45, 60, 75 and 90°C) was investigated. The unit weight and uniaxial compressive strength (UCS) of the geopolymer specimens were measured. Scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX) and X-ray diffraction (XRD) were also performed to characterize the microstructure and phase composition of the geopolymer specimens. The results show that the incorporation of SG not only improves the strength of the geopolymer specimens but also decreases the initial water content and thus the NaOH consumption at the same NaOH concentration required for geopolymer production. In addition, the inclusion of SG increases the unit weight of the geopolymer specimens, simply because SG has a much greater specific gravity than FA. The results also show that the strength of the FA/SG-based geopolymer develops rapidly within only 2 days and no obvious gain of the strength after 7 days. The optimum curing temperature (the curing temperature at which the maximum UCS is obtained) at a FA/SG ratio of 50/50 is around 75°C. Second, FA-based geopolymer concrete was synthesized and the effect of different factors including sodium silicate to sodium hydroxide (SS/SH) ratio, aggregate shape, water to fly ash (W/FA) ratio, curing time, water exposure and PCM inclusion on the compressive strength of the geopolymer concrete specimens cured at different ambient temperatures was studied. The results show that the UCS of the specimens increases with higher SS/SH and W/FA ratios up to a certain level and then starts to decrease at higher ratios. The results also indicate that a major portion of the strength of the specimens cured at ambient temperatures develops within the first four weeks. In addition the strength of the FA-based geopolymer concrete is slightly decreased with water exposure and PCM incorporation. Third, the mechanical and thermal properties of geopolymer mortar synthesized with FA and different amount of PCM were studied and the effect of incorporated PCM on the unit weight and UCS of geopolymer mortar was evaluated. SEM imaging was performed to identify the change of micro structure of the geopolymer mortar after incorporation of PCM. The thermal properties of the geopolymer mortar containing different amount of PCM were also characterized using differential scanning calorimetry (DSC) analysis. In addition model tests were performed using small cubicles built with geopolymer mortar slabs containing different amount of PCM to evaluate the effectiveness of geopolymer mortar wall with incorporated PCM in controlling the heat flow and internal temperature. The results indicate that both the unit weight and UCS of the geopolymer mortar decrease slightly after PCM is incorporated, mainly due to the small unit weight and low strength and stiffness of the PCM, respectively. However, the compressive strength of geopolymer mortar containing up to 20% PCM is still sufficiently high for applications in buildings. The results also show that the incorporation of PCM leads to substantial increase of heat capacity and decrease of thermal conductivity of the geopolymer mortar and is very effective in decreasing the temperature inside the cubicles. Finally, a numerical study on the thermal performance of geopolymer with incorporated PCM was carried out. In order to simulate the heat transfer through geopolymer containing PCM, a simplified method was first presented. The influence of phase transition was linked to the energy balance equation through variable specific heat capacity of the PCM-geopolymer. The thermal properties of the geopolymer containing PCM for the numerical analysis were determined using DSC and guarded heat flow (GHF) tests. The simplified method was validated based on the good agreement between the numerical and experimental results. With the validated model, the effect of various factors including the specific heat capacity, thermal conductivity and wall thickness on the thermal performance of PCM-geopolymer walls was studied. Then a modified numerical method was proposed for simulating the whole thermal transfer processes and the simulation results were used to conduct the economic evaluation of PCM-geopolymer walls for energy savings in buildings.
5
Spano, Julian. "The Development of an Amorphous Approach to Ambient Cured Blended Geopolymer Mortar Mixture Design." Thesis, Curtin University, 2021. http://hdl.handle.net/20.500.11937/82669.
Повний текст джерелаАнотація:
Current geopolymer formulation prescribes mixture proportions through bulk methods, considering both the inert and reactive composition of the mixture constituents. This is believe to be attributed to inconstancies in strength outcomes and production processes. This research aimed to further develop the amorphous approach to geopolymer formulation, where by geopolymer mixture proportions are prescribed with reference to the reactive composition of the feeder stocks. This research focused on binary, ternary and blended geopolymer binders within mortars.
6
Funke, Henrik L., Sandra Gelbrich, and Lothar Kroll. "An Alkali Activated Binder for High Chemical Resistant Self-Leveling Mortar." Universitätsbibliothek Chemnitz, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:ch1-qucosa-211751.
Повний текст джерелаАнотація:
This paper reports the development of an Alkali Activated Binder (AAB) with an emphasis on the performance and the durability of the AAB-matrix. For the development of the matrix, the reactive components granulated slag and coal fly ash were used, which were alkali activated with a mixture of sodium hydroxide (2 - 10 mol/l) and aqueous sodium silicate solution (SiO2/Na2O molar ratio: 2.1) at ambient temperature. A sodium hydroxide concentration of 5.5 mol/l revealed the best compromise between setting time and mechanical strengths of the AAB. With this sodium hydroxide concentration, the compressive and the 3-point bending tensile strength of the hardened AAB were 53.4 and 5.5 MPa respectively after 14 days. As a result of the investigation of the acid resistance, the AAB-matrix showed a very high acid resistance in comparison to ordinary Portland cement concrete. In addition, the AAB had a high frost resistance, which had been validated by the capillary suction, internal damage and freeze thaw test with a relative dynamic E-Modulus of 93% and a total amount of scaled material of 30 g/m2 after 28 freeze-thaw cycles (exposure class: XF3).
7
Villca, Pozo Ariel Rey. "Utilización de geopolímero para la mejora de las propiedades en morteros cal-puzolana y su empleo en países en desarrollo." Doctoral thesis, Universitat Politècnica de València, 2021. http://hdl.handle.net/10251/172663.
Повний текст джерелаАнотація:
[ES] El descubrimiento del cemento Portland ha cambiado nuestra forma de construir, pero también es el responsable de grandes emisiones de CO2 a la atmósfera durante su fabricación (~1450 ᴼC), agravando la crisis actual que está sufriendo nuestro planeta debido al cambio climático y sus consecuencias en todo el medio ambiente.
Por lo tanto, una alternativa más sostenible en la construcción es la utilización de la cal que necesita menor temperatura para su fabricación (~900 ᴼC). Si bien la introducción de puzolanas naturales o artificiales en morteros de cal han mejorado sus propiedades mecánicas y de durabilidad, estas aún tienen el inconveniente de ganar resistencias a edades largas de curado. Es por esta razón que en la presente tesis se pretende eliminar este inconveniente técnico, buscando la asociación de la cal con nuevos conglomerantes más sostenibles a partir de residuos para obtener morteros mixtos denominados cal/puzolana-geopolímero.
Los residuos estudiados fueron: el catalizador gastado de craqueo catalítico, la ceniza de cascara de arroz, la tierra diatomea de origen residual y la ceniza de lodo de depuradora. También se estudia una puzolana natural proveniente de la República de Guatemala.
En los morteros cal/puzolana (cal/FCC, cal/CCA, cal/CLD) se ha realizado sustituciones en peso hasta un 50 % de la mezcla cal/puzolana por geopolímero. El geopolímero se obtiene por una combinación del FCC como precursor y diferentes activadores alcalinos siendo estos la mezcla de: NaOH/Na2SiO3, NaOH/CCA, NaOH/TDN y NaOH/TDR. Los últimos tres sustituyen al silicato comercial como fuente de sílice alternativa.
Asimismo, se realizaron estudios a nivel mecánico y microestructural. Para los estudios microestructurales, tanto de muestras endurecidas como de materiales de partida, se emplearon como técnicas: FRX, ADL, TG, DRX y FESEM.
Los resultados han demostrado con éxito que añadir pequeñas cantidades de geopolímero sobre el sistema cal/puzolana fue notable, debido a que este potenció la formación de los nuevos productos de reacción, lo que mejoró la resistencia mecánica de los morteros desde las primeras horas de curado, llegando a obtener 7 veces más de resistencia que un mortero control cal/puzolana en 1 día de curado.
El reemplazo del silicato de sodio comercial por CCA, TDN, TDR, como fuente de sílice, condujo a mejores desempeños del mortero en términos de resistencia a la compresión. Además, redujo el coeficiente de absorción de agua por capilaridad y aumento el tiempo de exposición a los ciclos hielo-deshielo frente a los morteros activados con activadores comerciales.
Finalmente, los conglomerantes desarrollados en este estudio podría beneficiar tanto a la gestión de residuos como al desarrollo de materiales de construcción más sostenibles, aportando a los objetivos propuestos en la agenda 2030.[CA] El descobriment del ciment Portland ha canviat la nostra manera de construir, però també és el responsable de grans emissions de CO¿ a l'atmosfera durant la seva fabricació (~1450 ᴼC), agreujant la crisi actual que està patint el nostre planeta degut al canvi climàtic i les seves conseqüències en tot el medi ambient. Per tant, una alternativa més sostenible en la construcció és la utilització de la calç que necessita menor temperatura per a la seva fabricació (~900 ᴼC). Si bé la introducció de putzolanes naturals o artificials en morters de calç han millorat les seves propietats mecàniques i de durabilitat, aquestes encara tenen l'inconvenient de guanyar resistències a edats llargues de curat. És per aquesta raó que en la present tesi es pretén eliminar aquest inconvenient tècnic, buscant l'associació de la calç amb nous conglomerants més sostenibles a partir de residus per a obtenir morters mixtos denominats calç/putzolana-geopolímer. Els residus estudiats van ser: el catalitzador gastat del craqueig catalític, la cendra de closca d'arròs, la terra diatomea d'origen residual i la cendra de llot de depuradora. També es va estudiar una putzolana natural provinent de la República de Guatemala. En els morters calç/putzolana (calç/FCC, calç/CCA, calç/CLD) s'ha realitzat substitucions en pes fins a un 50 % de la barreja calç/putzolana per geopolímer. El geopolímer s'obté per una combinació del FCC com a precursor i diferents activadors alcalins, sent aquests la mescla de: NaOH/Na2SiO3, NaOH/CCA, NaOH/TDN i NaOH/TDR. Els últims tres substitueixen al silicat comercial com a font de sílice alternativa. Així mateix, es van realitzar estudis a nivell mecànic i microestructural. Per als estudis microestructurals, tant de mostres endurides com de materia primera, es van emprar tècniques com: FRX, ADL, TG, DRX i FESEM. Els resultats han demostrat amb èxit que afegir petites quantitats de geopolímer sobre el sistema calç/putzolana va ser notable, pel fet que aquest va potenciar la formació dels nous productes de reacció, la qual cosa va millorar la resistència mecànica dels morters des de les primeres hores de curat, arribant a obtenir 7 vegades més de resistència que un morter control calç/putzolana en 1 dia de curat. El reemplaçament del silicat de sodi comercial per CCA, TDN, TDR, com a font de sílice, va conduir a millors acompliments del morter en termes de resistència a la compressió. A més, va reduir el coeficient d'absorció d'aigua per capil·laritat i va augmentar el temps d'exposició als cicles gel-desgel enfront dels morters activats amb activadors comercials. Finalment, els conglomerants desenvolupats en aquest estudi podrien beneficiar tant a la gestió de residus com al desenvolupament de materials de construcció més sostenibles, aportant als objectius proposats en l'Agenda 2030.
[EN] The discovery of Portland cement has changed the way we build; however, it is also responsible for large CO2 emissions into the atmosphere during its manufacturing (~ 1450 ᴼC), thereby aggravating the current crisis that our planet is suffering due to climate change and its consequences in the environment. Thus, a more sustainable alternative in construction is the use of lime that requires a lower temperature for its manufacturing (~ 900 ᴼC). The introduction of natural or artificial pozzolans in lime mortars has improved their mechanical properties and durability. Nevertheless, they present some technical disadvantages, as the low compressive strength, especially at early curing time. This thesis aims to eliminate this technical disadvantage by mixing lime with new more sustainable binders derived from waste, obtaining mixed mortars called lime/pozzolan-geopolymer The waste materials studied included fluid catalytic cracking residue (FCC), rice husk ash (CCA), residual diatomite (TDR) and sewage sludge ash (CLD). A natural pozzolan from the Republic of Guatemala was also studied. In the experimental procedure, in lime/pozzolan mortar mixtures (lime/FCC, lime/CCA, lime/CLD), up to 50% of their weight was substituted by geopolymer. The geopolymer is obtained by combining FCC as a precursor, and different alkaline activator mixtures including NaOH/Na2SiO3 (commercial waterglass), NaOH/CCA, NaOH/TDN, and NaOH/TDR, with the last three being an alternative silica source to commercial waterglass. In the same way, both mechanical and microstructural studies were carried out. The following techniques were used: XRF, ADL, TG, XRD and FESEM to assess the microstructural properties of both the raw materials and the hardened samples. The results have demonstrated that adding small amounts of geopolymer to the lime/pozzolan system was remarkable; it enhanced the formation of new reaction products, which improved the mechanical strength of the mortar from the first hours of curing, obtaining 7 times more strength than the lime/pozzolan control mortar in 1 day of curing. The replacement of commercial waterglass by CCA, TDN, TDR, as a source of silica, led to better performance of the mortar in terms of compressive strength. In addition, the coefficient of water absorption by capillarity was reduced and the exposure time during freezing-thawing cycles was increased compared to mortars activated with commercial activators. Finally, the binders developed in this study could benefit both waste management and the development of more sustainable construction materials, contributing to the objectives proposed in the 2030 Agenda.
Gracias al programa ADSIDEO-COOPERACIÓN de la Universitat Politècnica de València, que me ha brindado financiación para la presente investigación.
Villca Pozo, AR. (2021). Utilización de geopolímero para la mejora de las propiedades en morteros cal-puzolana y su empleo en países en desarrollo [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/172663
TESIS
8
Froener, Muriel Scopel. "Valorização de cinza de fundo por meio da síntese de ligantes geopoliméricos : otimização de traços em pasta e avaliação dos sistemas em argamassas." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/148735.
Повний текст джерелаАнотація:
Com o intuito de valorizar resíduos localmente disponíveis foi selecionada como principal matéria prima desta pesquisa, uma cinza de fundo proveniente da queima de carvão mineral para geração de energia em uma usina termoelétrica do Estado. Uma vez que este resíduo ainda não possui destinação que lhe agregue valor, o mesmo é amplamente utilizado no preenchimento de cavas de extração de carvão ou então permanece em bacias de sedimentação, criando assim um panorama suscetível a problemas ambientais além de gerar elevados custos para seu transporte. Neste âmbito surgem com grande destaque o desenvolvimento de ligantes álcali-ativados, dentre estes os geopolímeros, que por utilizarem diversos materiais provenientes de resíduos industriais na sua produção apresentam grande redução na emissão de CO2 e no consumo energético quando são comparados ao cimento Portland. Estes materiais consistem na ativação alcalina de aluminossilicatos amorfos (precursor), sendo estes na maioria das vezes resíduos ou subprodutos industriais. Sendo assim, o presente trabalho teve por objetivo otimizar traços, com base em cinza de fundo, para a produção de ligantes e argamassas geopoliméricas. O método experimental proposto se encontra dividido em diferentes fases subsequentes à seleção e caracterização das matérias primas: (1) síntese de sistemas geopoliméricos em pasta, (2) otimização dos geopolímeros em pasta e (3) produção de argamassas geopoliméricas com verificação das propriedades mecânicas e de absorção de água. A partir da análise dos resultados observou-se que o teor de Na2O = 15% com uma concentração de silicatos solúveis no ativador (expresso como a relação molar SiO2/Na2O) igual a 1 (sistema CF-15-1,0), se mostrou ideal para as misturas com cinza de fundo. A adição de silicatos solúveis propiciou um incremento de resistência aos sistemas produzidos no geral, atingindo em alguns casos o acréscimo de até 40% na resistência aos 28 dias. Quando avaliados diferentes tamanhos de partículas a partir do beneficiamento mecânico das cinzas, observou-se que um diâmetro médio de 7 μm é o mais adequado. Com relação aos sistemas binários e híbridos testados quando comparados aos seus referenciais moldados apenas com cinza de fundo, nenhuma combinação foi capaz de superar as resistências dos referenciais. Quando produzidas argamassas geopoliméricas a partir das combinações com outros resíduos (lodo de anodização do alumínio e catalizador de equilíbrio - resíduo proveniente do processo de craqueamento catalítico em leito fluidizado de frações pesadas do petróleo) e cimento Portland, houveram quedas na resistência à compressão de maneira generalizada. A argamassa utilizada como referência (CF-15-1,0) se mostrou a matriz mais densa e consequentemente atingiu o maior desempenho mecânico com menor absorção de água por capilaridade.In order to valorise locally available residues, bottom ash (BA) from a thermo-electrical plant was selected as the main material within the project presented here. BA does not have any commercial value and normally it is used to refill old coal mines or it is disposed in extended basins increasing the environmental impact as well as the cost related to its transport. Also there exist convincing interests in the development of non-conventional binders, i.e. alkali-activated cements (geopolimers), which can be a feasible pathway to the valorization of different industrial wastes. When alkali-activated concrete is produced under optimal conditions, it can exhibits similar or even higher mechanical performance and durability when compared to traditional Portland cement concrete. These materials are based on aluminosilicate mineral (precursor) chemically activated by an alkaline solution (activator). Thus, this project is focused in the optimization dosage of bottom ash based geopolymers in pastes and the subsequent mortars production and assessment. Mechanical performance and some permeability properties of the developed geopolyemrs were assessed. The results showed that 15% of Na2O in respect to the bottom ash with 1,0 SiO2/Na2O molar ratio as activator produced more suitable geopolymeric paste. This material was used as a reference system for the development of the proposed project. Also mechanical treatement applied to the BA reduced x% the mean particle size obteining 7 μm and this improved up to ~95% the mechanical performance of the produced geopolymers. The inclusion of Portland cement as a secondary precursor did not have significant effect under the compressive strength when compared to the BA-based systems. Furthermore, the use of other sorces of aluminosilicates, such as aluminium anodizing sludge and spent fluid cracking catalyst, also did not presented any improvement in the analysed geopolimeric systems. BA-based systems activated at 15% of Na2O using an alkali activator solution with a Ms of 1.0 showed the lowest permability and higher mechanical performance.
9
Zerzouri, Maroua. "Faisabilité d’élaboration des poudres pré-géopolymères par mécanosynthèse : caractérisation physico-chimique et application aux pâtes, mortiers et enrobés bitumineux." Thesis, Université Gustave Eiffel, 2021. http://www.theses.fr/2021UEFL2039.
Повний текст джерелаАнотація:
Les géopolymères sont des matériaux inorganiques fabriqués à partir de composés d’origine naturelle (kaolin, par exemple), ou issus de déchets industriels (cendres volantes, laitiers de hauts fourneaux…). Leurs excellentes propriétés physico-chimiques et mécaniques justifie l’intérêt grandissant qu’ils suscitent dans le domaine de la construction. Toutefois, leur potentiel d’utilisation reste limité en raison de l’emploi, lors de leur préparation, de solutions alcalines fortement concentrées présentant des risques sanitaires importants et d’une difficulté de stockage et transport ; d’où la nécessité d’implémenter des techniques de confection sans solvant. Cette thèse vise à proposer une nouvelle méthode d’élaboration de poudres pré-géopolymères (PGP) par « mécanosynthèse » faciles à transporter et à stocker. Plusieurs matières premières, de différentes natures et compositions chimiques, ont été testées comme précurseurs aluminosilicatés (cendres volantes, métakaolin, laitier de hauts fourneaux et argile) ; elles ont été activées par différents mélanges alcalins (NaOH, KOH, Na2SiO3 et CaO), à des ratios massiques fixés. L’effet de plusieurs paramètres de procédé a été considéré, notamment le temps et la vitesse de broyage. Les poudres pré-géopolymères produites ont été ensuite incorporées dans des formulations de pâtes, de mortiers et d’enrobés bitumineux. Les propriétés physico-chimiques et mécaniques des pâtes produites ont été étudiées. Les résultats obtenus ont été comparés à ceux des pâtes confectionnées par la méthode classique dans les mêmes conditions. La cinétique de la réaction de géopolymérisation des pâtes a été suivie par spectrométrie infrarouge in situ juste après l’hydratation des PGP. Par ailleurs, le procédé de mécanosynthèse indirecte a été utilisé pour améliorer la réactivité de l’argile.Les résultats ont mis en évidence l’efficacité du procédé de mécanosynthèse pour l’élaboration de poudres pré-géopolymères. Celles-ci donnent lieu après hydratation à des pâtes géopolymères avec une structure semblable à celle des géopolymères classiques. Ce procédé a également permis d’améliorer les performances mécaniques des produits géopolymères. Les poudres pré-géopolymères à base d’argile illitique produites par mécanosynthèse indirecte donnent lieu à des pâtes avec une résistance mécanique atteignant 72,5 MPa après 28 jours de cure à 20 °C et 50 % d’humidité relative, contre 12,5 MPa dans le cas classique. Les résultats obtenus sur les mortiers à base de PGP-laitier montrent des résistances mécaniques qui atteignent 38 MPa après 28 jours de cure.Enfin, les résultats préliminaires sur les enrobés bitumineux à base de PGP révèlent une meilleure tenue à l’eau et résistance à l’orniérage, même après 100.000 cycles, que celles des formules de référence sans PGPGeopolymers are inorganic materials made from compounds of natural origin (kaolin, for example), or from industrial waste (fly ash, blast furnace slag, etc.). Their excellent physicochemical and mechanical properties justify the growing interest they arouse in the construction field. However, their potential of employment remains limited due to the use, during their preparation, of highly concentrated alkaline solutions causing significant health risks and transport storage difficulty; hence it is necessary to implement solvent-free manufacturing techniques.This thesis aims to propose a new producing pre-geopolymer powders (PGP) method by “mechanosynthesis” that are easy to transport and store. Several raw materials, of different types and chemical compositions, were tested as aluminosilicate precursors (fly ash, metakaolin, blast furnace slag and clay); they were activated by different alkaline mixtures (NaOH, KOH, Na2SiO3 and CaO), at fixed mass ratios. The effect of several process parameters was considered, including milling time and speed rotation. The produced pre-geopolymer powders were then incorporated into formulations of pastes, mortars and bituminous mixes. The pastes physicochemical and mechanical properties were studied. The obtained results were compared with those of pastes made by the conventional method under the same conditions. The kinetics of pastes geopolymerization reaction were followed by infrared spectrometry in situ just after the hydration of the PGP. In addition, the indirect mechanosynthesis process has been used to improve the reactivity of clay.The results demonstrated the mechanosynthesis process efficiency for producing the pre-geopolymer powders. These give rise after hydration to geopolymer pastes with a similar structure to that of conventional geopolymers. This process has also helped to improve the mechanical performances of geopolymer products. The pre-geopolymer powders based on illitic clay, produced by indirect mechanosynthesis, give rise to pastes with mechanical resistance reaching 72.5 MPa after 28 curing days at 20 ° C and 50% of relative humidity, against 12.5 MPa for the classic case. The results obtained on slag-based mortars show mechanical strengths reaching 38 MPa after 28 curing daysFinally, the preliminary results on slag PGP-based bituminous mixes reveal better water and rutting resistance, even after 100,000 cycles, than those of the reference formulas without PGP
10
Carvalheiras, João António de Sousa. "Estudo da reciclagem de resíduos de fibras de vidro em geopolímeros, argamassas e telas de impermeabilização." Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/17198.
Повний текст джерелаАнотація:
Mestrado em Engenharia de MateriaisDesenvolveu-se uma parceria entre a Universidade de Aveiro, Ria Blades, S.A. e Saint-Gobain Weber Portugal, S.A. com objetivo de encontrar formas de aproveitamento dos resíduos de fibra de vidro produzidos na Ria Blades, S.A., que atualmente são depositados em aterro. O trabalho incidiu em três produtos-alvo: telas de impermeabilização, argamassas e geopolímeros. No que diz respeito às telas de impermeabilização, de base polimérica (poliuretano), os resíduos foram aplicados como agente de reforço. Estudou-se o efeito da incorporação das fibras na aderência, na resistência à tração e na durabilidade perante ciclos de gelo-degelo. Quando incorporadas fibras de vidro, registou-se um aumento na aderência ao suporte relativamente à amostra padrão e um crescimento (de cerca de 20 vezes) na resistência à tração. Na incorporação em argamassas bastardas, o objetivo foi perceber o efeito da substituição das fibras poliméricas atualmente usadas, pelas fibras de vidro residuais. Estudou-se o efeito na percentagem de ar incorporado e densidade do amassado, bem como a variação de massa e de dimensão, módulo de elasticidade, resistência à compressão e flexão do produto endurecido. A incorporação de fibra de vidro não aparenta prejudicar o desempenho das argamassas, sendo os resultados semelhantes nas amostras padrão. Apesar de as quantidades incorporadas serem apenas de 0,1%, é possível que a utilização destes resíduos tenha impactos economicamente positivos para as duas empresas. Nos geopolímeros, a incorporação das fibras de vidro pretendeu explorar dois efeitos distintos: (i) como ligante, em substituição parcial de metacaulino (até 40% em massa); (ii) como agente de reforço da mistura. Numa primeira fase, foi necessário caracterizar as matérias primas e os resíduos para respeitar as razões molares que asseguram uma maior extensão da reação. Foram avaliadas a densidade aparente, resistência à compressão, absorção de água ao longo do tempo de cura e ainda a resistência à flexão no caso de as fibras funcionarem como agente de reforço. Como substituto parcial do metacaulino verifica-se uma descida na resistência à compressão com o aumento de resíduo de fibra de vidro. No entanto com a otimização da formulação com 20% de fibras de vidro foi possível duplicar o valor da resistência à compressão (> 8MPa). Como agente de reforço, os resultados mostram ganhos de resistência à compressão de 4 vezes quando se incorporam fibras de 6mm de comprimento, relativamente a amostras sem reforço. O uso de fibras mais longas (20mm) é mais eficaz no aumento da resistência à flexão.
A partnership has been developed between the University of Aveiro, Ria Blades, S.A. and Saint-Gobain Weber Portugal, S.A. in order to find a way to recycle the glass-fibre residues produced from Ria Blades, S.A. that are currently being send to landfill. Three possible target-products were exploited: waterproofing membrane, mortars and geopolymers. On the waterproofing membrane, based on polyurethane, the residues were incorporated as reinforcing agents and effects on adhesion, tensile strength and resistance to freeze-thaw cycles were determined. An increase of 20 times on the tensile strength has been registered, relatively to the standard sample. On mortars, the aim was to understand the effect of the substitution of the currently used reinforcing-fibres for the wasted glass-fibres. Fresh-state properties such as the entrained air content and density were evaluated. The effect on relevant hardened-state properties was then studied, including the variation of mass and dimensions, the compressive and flexural strengths, and elastic modulus. The behaviour of the mortars doesn’t seem to be affected by the incorporation of glass-fibres because the results from both the mortars with and without glass-fibres are similar. Although the quantity of incorporated glass-fibres is only around 0,1%, its use may have positive economic benefits for both companies. In geopolymers, the incorporation of wasted glass-fibres aimed to explore two distinct effects: (i) use as binder, partially substituting the metakaolin (up to 40 wt.%); (ii) use as reinforcing agent of common matrixes. On the first stage it was necessary to characterize both the raw materials and the glass-fibres, in order to achieve the desirable molar ratios that assure an extended reaction. Hardened samples were characterized in terms of density, compressive strength and water absorption. In the attempted reinforced geopolymers the flexural strength was additionally tested. When the glass-fibres were used as partial substitute of metakaolin, a drop of the compressive strength was observed for higher contents of glass-fibres. Optimizing the mixture for 20 % of glass-fibres allowed to duplicate the compressive strength (> 8 MPa). When 6 mm glass-fibres were used as a reinforcing agent, the compressive strength increased 4 times when compared to samples without reinforcement. Using 20 mm fibres is the most effective way of improving flexural strength.
Частини книг з теми "Geopolymer mortars"
1
Gibson, Robin R. "The Use of Aluminosilicates to Create Novel, High Performance and Sustainable Binders for Mortars, Plasters and Renders With Class Leading Low CO2Footprints." In Geopolymer Binder Systems, 54–71. 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959: ASTM International, 2013. http://dx.doi.org/10.1520/stp156620120076.
Повний текст джерела
2
Faria, T., J. Ferdous, and G. M. Sadiqul Islam. "Ternary Combination of Industrial Wastes for Sustainable Geopolymer Mortars." In Lecture Notes in Civil Engineering, 177–87. Singapore: Springer Singapore, 2021. http://dx.doi.org/10.1007/978-981-16-5547-0_18.
Повний текст джерела
3
Dhakal, Milap, Kunal Kupwade-Patil, Erez N. Allouche, Charles Conner la Baume Johnson, and Kyungmin Ham. "Optimization and Characterization of Geopolymer Mortars using Response Surface Methodology." In Ceramic Engineering and Science Proceedings, 135–49. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2013. http://dx.doi.org/10.1002/9781118807743.ch12.
Повний текст джерела
4
Mallikarjuna Rao, G., and C. H. Kireety. "Durability Studies on Alkali Activated Fly Ash and GGBS-Based Geopolymer Mortars." In Lecture Notes in Civil Engineering, 85–97. Singapore: Springer Singapore, 2018. http://dx.doi.org/10.1007/978-981-13-3317-0_8.
Повний текст джерела
5
Panagiotopoulou, Ch, A. Asprogerakas, G. Kakali, and S. Tsivilis. "Synthesis and Thermal Properties of Fly-Ash Based Geopolymer Pastes and Mortars." In Ceramic Engineering and Science Proceedings, 17–28. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2011. http://dx.doi.org/10.1002/9781118095393.ch2.
Повний текст джерела
6
Jitha, P. T., B. Sunil Kumar, and S. Raghunath. "Studies on Strength Development of Geopolymer Stabilised Soil-LPC (Lime-Pozzolana-Cement) Mortars." In Earthen Dwellings and Structures, 215–24. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-5883-8_19.
Повний текст джерела
7
Singh, N. B., S. K. Wali, S. K. Saxena, and Mukesh Kumar. "Properties of Calcined Clay-Based Geopolymer Mortars in Presence of Alccofine Powder and Recron Fiber." In RILEM Bookseries, 759–66. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-2806-4_84.
Повний текст джерела
8
Andrade, Igor Klaus R., Beatryz C. Mendes, Leonardo G. Pedroti, Carlos M. F. Vieira, and J. M. Franco de Carvalho. "Influence of the Sand Content on the Physical and Mechanical Properties of Metakaolin-Based Geopolymer Mortars." In Characterization of Minerals, Metals, and Materials 2022, 381–89. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-92373-0_37.
Повний текст джерела
9
Revathy, V., and Gouri Antherjanam. "Strength Comparison of Cement Mortar and Geopolymer Mortar." In Lecture Notes in Civil Engineering, 175–82. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-26365-2_17.
Повний текст джерела
10
Panda, Biranchi, Nisar Ahamed Noor Mohamed, Yi Wei Daniel Tay, and Ming Jen Tan. "Bond Strength in 3D Printed Geopolymer Mortar." In RILEM Bookseries, 200–206. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-99519-9_18.
Повний текст джерелаТези доповідей конференцій з теми "Geopolymer mortars"
1
Moukannaa, Samira, Ali Nazari, Ali Bagheri, Mohamed Loutou, and Rachid Hakkou. "Thermal resistance of alkaline fused phosphate sludge-based geopolymer mortar." In The 13th international scientific conference “Modern Building Materials, Structures and Techniques”. Vilnius Gediminas Technical University, 2019. http://dx.doi.org/10.3846/mbmst.2019.073.
Повний текст джерелаАнотація:
The present study investigates the thermal behaviour of phosphate sludge-based geopolymers. Phosphate sludge which is a by-product from phosphate beneficiation processes was activated using the alkaline fusion method to improve the geopolymer activity of this material. Then, the mechanical properties as well as the thermal behaviour of the resulted geopolymer mortar were studied. The effect of sodium hydroxide addition and fusion temperature on the mechanical properties and the thermal behaviour of the geopolymers were assessed using compressive strength tests before and after thermal shock cycles at different temperatures (350, 500, 650 °C). The mineralogical composition of the fused materials was investigated using XRD measurement and the microstructure of the geopolymer mortars was studied using FTIR. The obtained results showed that NaOH content as well as the temperature of fusion are essential parameters controlling the structure and the strength of the developed geopolymeric gel. Exposure to elevated temperatures up to 650 °C induces a decrease in compressive strength between 58 and 71%. However, a further increase in the temperature of exposure till 800 °C induces a development of compressive strength. Overall, geopolymers with good compressive strength up to 40 MPa could be synthesized in the optimum conditions of fusion: 10% of NaOH and 550 °C.
2
Aygörmez, Yurdakul, Orhan Canpolat, Mukhallad Al-Mashhadani, Mucteba Uysal, and Furkan Şahin. "Sulfate resistance of sustainable geopolymer mortars." In Fifth International Conference on Sustainable Construction Materials and Technologies. Coventry University and The University of Wisconsin Milwaukee Centre for By-products Utilization, 2019. http://dx.doi.org/10.18552/2019/idscmt5069.
Повний текст джерела
3
"Properties of Fly Ash-Based Geopolymer Mortars." In SP-334: Sustainable Concrete with Beneficial Byproducts. American Concrete Institute, 2019. http://dx.doi.org/10.14359/51720256.
Повний текст джерела
4
"Fly Ash-Based Lightweight Geopolymer Mortars for Fire Protection." In SP-326: Durability and Sustainability of Concrete Structures (DSCS-2018). American Concrete Institute, 2018. http://dx.doi.org/10.14359/51711008.
Повний текст джерела
5
Canpolat, Orhan, Furkan Şahin, Mucteba Uysal, Mukhallad Al-Mashhadani, and Yurdakul Aygörmez. "Using different types of aggregates including waste concrete in the production of geopolymer mortars." In Fifth International Conference on Sustainable Construction Materials and Technologies. Coventry University and The University of Wisconsin Milwaukee Centre for By-products Utilization, 2019. http://dx.doi.org/10.18552/2019/idscmt5070.
Повний текст джерела
6
Aygörmez, Y., Orhan Canpolat, M. M. Al-mashhadani, and M. Uysal. "Compressive and flexural strength behaviors of metakaolin based geopolymer mortars manufactured by different procedures." In GREEN DESIGN AND MANUFACTURE: ADVANCED AND EMERGING APPLICATIONS: Proceedings of the 4th International Conference on Green Design and Manufacture 2018. Author(s), 2018. http://dx.doi.org/10.1063/1.5066927.
Повний текст джерела
7
Abufarsakh, Ruwa, Hassan Noorvand, Gabriel Arce, Marwa Hassan, and Sujata Subedi. "Fresh and Hardened Properties of Potassium Hydroxide Activated Metakaolin and Fly Ash-Based Geopolymer Mortars." In Tran-SET 2022. Reston, VA: American Society of Civil Engineers, 2022. http://dx.doi.org/10.1061/9780784484609.034.
Повний текст джерела
8
Pilien, Vincent P., Jason Maximino C. Ongpeng, Andres Winston C. Oreta, Lessandro Estelito O. Garciano, Michael Angelo B. Promentilla, Ernesto J. Guades, and Julius L. Leaño Jr. "Fly ash Based Banana Fiber-reinforced Geopolymer Mortar." In IABSE Symposium, Prague 2022: Challenges for Existing and Oncoming Structures. Zurich, Switzerland: International Association for Bridge and Structural Engineering (IABSE), 2022. http://dx.doi.org/10.2749/prague.2022.1212.
Повний текст джерелаАнотація:
<p>Banana fiber-reinforced geopolymer (BFRG) mortar is an engineered cementitious composite (ECC) that can be used in masonry units and repair system of different concrete elements. During geopolymerization, only small amount of carbon dioxide (CO2) is generated and reinforcing it with banana fibers (BFs) made the matrix compact and more earth-friendly. BFs treated with sodium hydroxide (NaOH) enhanced its surface roughness and significantly increased its tensile properties. Design of experiment (DOE) with 13 design mixtures are aimed to obtain the highest value of compressive strength. Factors considered in the DOE are the silica fume (SF) and BF content, ratios of the activator to precursor, water to solids, NaOH to water glass (WG) and fly ash (FA) to sand. The experiment revealed the optimum BFRG mortar and the compatibility of BF to the geopolymer which gained great values for workability, split tensile strength and compressive strength.</p>
9
Saloma, Maulid Muhammad Iqbal, and Ibnu Aqil. "Sulfate resistance of fly ash-based geopolymer mortar." In 3RD ELECTRONIC AND GREEN MATERIALS INTERNATIONAL CONFERENCE 2017 (EGM 2017). Author(s), 2017. http://dx.doi.org/10.1063/1.5002232.
Повний текст джерела
10
Pilien, Vincent P., Lessandro Estelito O. Garciano, Michael Angelo B. Promentilla, Ernesto J. Guades, Julius L. Leaño, Andres Winston C. Oreta, and Jason Maximino C. Ongpeng. "Banana Fiber-Reinforced Geopolymer-Based Textile-Reinforced Mortar." In IOCI 2022. Basel Switzerland: MDPI, 2022. http://dx.doi.org/10.3390/engproc2022017010.
Повний текст джерелаЗвіти організацій з теми "Geopolymer mortars"
1
Wilson, Clint, Jaclyn Mathis, Lawrence Clark, and Anthony Delgado-Connor. Geopolymer nanoceramic mortar liner system for corrosion protection and rehabilitation of stormwater piping : final report on Project F14-AR05. Construction Engineering Research Laboratory (U.S.), August 2017. http://dx.doi.org/10.21079/11681/22787.
Повний текст джерела