Metakaolin
Mostrando 13-24 de 42 artigos, teses e dissertações.
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13. Thermal, Mechanical and Microstructural Analysis of Metakaolin Based Geopolymers
In the present work, geopolymer matrices were developed by alkali activation of metakaolin, using NaOH and sodium silicate as activators. The samples of metakaolin and matrices were studied by thermal analysis (TGA/DTA) at temperatures between 22°C and 1000°C in a nitrogen atmosphere with a heating rate of 10°C/min. The analyses showed gradual mass losses
Mat. Res.. Publicado em: 20/05/2019
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14. Efeito do envelhecimento acelerado sobre as propriedades de microconcreto reforçado com fibras longas de sisal
Resumo Neste trabalho dois microconcretos, com e sem metacaulinita, foram dosados para produção de compósitos laminados reforçados com fibras longas de sisal. Para garantir uma matriz livre de hidróxido de cálcio foi determinado o teor ideal de metacaolinita por análise termogravimétrica de pastas com teores de substituição de 20%, 30% e 40 nas ida
Ambient. constr.. Publicado em: 2019-03
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15. Development of metakaolin and geopolymer proppants with nanocarbon materials
Abstract From the first hydraulic fracturing in the 40’s until nowadays, the techniques of each process step have evolved significantly. This study presents a new approach on the development of metakaolin (MK) and geopolymer based proppant with and without nanocarbon materials such as multi-walled carbon nanotubes and graphene oxide. For manufacturing the
Cerâmica. Publicado em: 2019-01
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16. Effect of sawdust as porosity agent on final properties of geopolymers
Abstract The geopolymers synthesis are based on geopolymerization, a sequence of reactions processed in an alkaline medium through oligomers providing a three-dimensional molecular structure. In this work, the polycondensation of metakaolin was performed with alkaline activators (NaOH and sodium silicate), wood sawdust and other additives. Two different comp
Cerâmica. Publicado em: 2019-01
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17. Retracción química de pastas de cemento con incorporación de metacaolín
Abstract This study shows the influence of partial replacement of Portland cement by metakaolin in the hydration reactions and chemical shrinkage of cementitious pastes. For this, pastes were prepared using metakaolin replacements of 5, 10 and 20% by mass, and a reference paste, using a constant water/solid ratio of 0,5. Chemical shrinkage was measured conti
Ambient. constr.. Publicado em: 2018-09
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18. Fracture Properties of Geopolymer Concrete Based on Metakaolin, Fly Ash and Rice Rusk Ash
Geopolymers are exclusively mineral nature and are considered an alternative to materials based on Portland clinker, whose production accounts for about 5% of anthropogenic CO2 emissions in the world. The geopolymer cement concrete (GCC) may be prepared from natural oxide-aluminosilicates such as metakaolin (MK), or synthetic, such as fly ash (FA) together w
Mat. Res.. Publicado em: 17/11/2017
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19. On The Mechanical Behavior of Metakaolin Based Geopolymers Under Elevated Temperatures
Geopolymers may be described as solid and stable synthesized aluminosilicate materials, whose properties are generally believed to provide a superior durability behavior. The work in hand presents the results of an experimental investigation on the thermomechanical behavior of geopolymer matrices composed by metakaolin (MK), silica fume (SF) and blast furnac
Mat. Res.. Publicado em: 13/07/2017
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20. Study on the NaOH/metakaolin Ratio and Crystallization Time for Zeolite a Synthesis from Kaolin Using Statistical Design
The NaOH/metakaolin ratio and crystallization time were studied for the synthesis of zeolite NaA from a sample of kaolin from a Capim mine. The tests were carried out by using statistical design with axial points and replication of the central point. The samples obtained were characterized by X-ray diffraction (DRX), scanning electron microscopy and chemical
Mat. Res.. Publicado em: 13/04/2017
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21. Metallurgical characterization of kaolin from Atacama, Chile
Abstract In order to determine the exploitation potentiality of a kaolin deposit from Atacama in the north of Chile, two types of kaolin (K-1 and K-2) were characterized by XRD, XRF, SEM/EDXS, size distribution, whiteness and DSC. Kaolinite, quartz, muscovite and albite were recognized as main constituents of the ore deposit, and also a significant amount of
REM, Int. Eng. J.. Publicado em: 2016-12
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22. Geopolymer/PEG Hybrid Materials Synthesis and Investigation of the Polymer Influence on Microstructure and Mechanical Behavior
Geopolymers are aluminosilicate inorganic polymers, obtained from the alkali activation of powders containing SiO2+Al2O3>80wt%, mainly proposed as environmentally friendly building materials. In this work, metakaolin-based geopolymers have been prepared and a water-soluble polymer, polyethylene glycol (PEG), has been added in different percentages to obtain
Mat. Res.. Publicado em: 25/08/2015
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23. Synthesis and characterization of zeolite NaP using kaolin waste as a source of silicon and aluminum
The synthesis of zeolite NaP using kaolin waste, from the Amazon region, as a predominant source of silicon and aluminum has been studied. The zeolitisation process occurred in hydrothermal conditions using static autoclaving and the effects of time, temperature, and the Si/Al ratio were investigated. The starting material and the phases formed as reaction p
Mat. Res.. Publicado em: 25/03/2014
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24. Steel corrosion assessment by electrochemical impedance on metakaolin blended mortars
Since Corrosion of reinforcing steel in concrete is the cause of major economic losses, Portland cement has been traditionally replaced by cements blended with pozzalanic materials, most of which have been found to reduce the corrosion of steel. This paper shows the results of an experimental research aimed to investigate the corrosion of reinforcement in mo
Mat. Res.. Publicado em: 05/11/2013