Geopolymer
Mostrando 1-12 de 26 artigos, teses e dissertações.
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1. Mix design formulation range for metakaolin-based geopolymer synthesis
Abstract This article presents a range of mix design formulations to obtain metakaolin-based geopolymer synthesis. Geopolymer samples were synthesized from metakaolin, a 10 M sodium hydroxide solution, and alkaline sodium silicate. These three components were mixed in different proportions to form a paste which was molded in a cylindrical shape, set at room
REM - International Engineering Journal. Publicado em: 2022
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2. Characterization and mechanical properties of one-part geopolymer based on a pure metakaolin
Abstract Geopolymers are amorphous silicate polymers that have been extensively studied due to their applications, scientific and technical relevance, and their potential as cement in substitution to Portland. Much of the focus has been in the use of precursors and aggregates that are rarely pure and homogeneous with the use of tailings being very common. Th
REM - International Engineering Journal. Publicado em: 2022
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3. Use of glass waste in the production of metakaolin-based geopolymer submitted to room temperature and thermal curing
Resumo O metacaulim é a principal matéria-prima utilizada na síntese de geopolímeros, embora a relação entre os teores de sílica e alumina não seja a ideal. Normalmente, o teor de SiO 2 é ajustado com o uso de silicatos presentes na solução ativadora. Uma opção ecoeficiente seria o uso de resíduos de vidro como fonte adicional de sílica. Este
Ambiente Construído. Publicado em: 2022
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4. Effects of the addition of graphene on the compressive strength of geopolymeric mortar developed from k-feldspar mining waste
Abstract Contemporary organizations are showing a growing interest in the reuse of solid waste from industrial processes with the intention of reducing environmental impacts and reducing costs. The mining activity is one of the main waste generators in Brazil. In parallel, geopolymeric materials have been gaining prominence in studies that make it a possible
REM, Int. Eng. J.. Publicado em: 2021-09
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5. Evaluation of the properties of a foamed geopolymer developed with different types of metakaolin
Abstract The physical and mechanical properties of foamed geopolymers were determined. The geopolymers were made with two different metakaolins (from Metacaulim do Brasil - MB, and Pantano Grande/RS - MPG) as precursors, with NaOH and Na2SiO3 as activators, and with the addition of foam, which was produced with the foaming agent diethanolamide of coconut fat
Cerâmica. Publicado em: 2021-06
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6. Use of rice husk ash to produce alternative sodium silicate for geopolymerization reactions
Abstract This study investigated the feasibility of synthesizing sodium silicate from rice husk ash (RHA) and its application to produce geopolymers. Samples were prepared at different SiO2/Al2O3 molar ratios (3.0, 3.5, and 4.0) for both sodium silicates (commercial and from RHA). They were underwater cured at 60 ºC for 1 h and then at room temperature (25
Cerâmica. Publicado em: 2021-03
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7. Carbon emissions associated with two types of foundations: CP-II Portland cement-based composite vs. geopolymer concrete
ABSTRACT The cement industry is the second-largest single industrial emitter in the world and therefore has an important role to play in reducing the intensity of its carbon emissions: participation of the sector is important to contribute to the goal of the Paris Climate Change Agreement to limit global warming. One of the strategies for reducing the carbon
Matéria (Rio J.). Publicado em: 25/11/2019
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8. Development of Geopolymers for Catalyst Support Applications
A geopolymer with high specific surface area was synthesized from metakaolin, amorphous silica and KOH, in the absence of foaming or saponification agents. The mixture modelling technique was selected for this study among the Design of Experiments tools, using surface area and total pores volume as response variables. The Si/K = 2.46 and Si/Al = 1.37 ratios
Mat. Res.. Publicado em: 25/11/2019
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9. Reuse of iron ore tailings in the production of geopolymer mortars
Abstract A great variety of silica and alumina-rich materials have been investigated in the production of alkaline activated binders (or geopolymers) with low environment impact, e.g. low CO2 emissions. Geopolymer mortars and concretes may be more environmentally friendly if not only Portland cement but also natural aggregates (sand, gravel) are replaced wit
REM, Int. Eng. J.. Publicado em: 16/09/2019
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10. Effect of Curing Temperature, Activator Solution Composition and Particle Size in Brazilian Fly-Ash Based Geopolymer Production
The geopolymer binder is a relatively new class of inorganic binding material of elevated mechanical strength and good chemical properties. This can be produced using clay minerals or byproducts of the industrial processes, such as metakaolin, fly-ash and blast furnace slag. In this work, geopolymers were produced by alkaline activation of a Brazilian fly-as
Mat. Res.. Publicado em: 22/08/2019
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11. 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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12. Synthetic Aluminosilicates for Geopolymer Production
Abstract The use of geopolymer has been studied as a potential substitute for Portland cement due to lower CO2 emission and improvements on structural properties. Some of the major raw materials used in the manufacture of the geopolymer are: steel slag, fly ash and metakaolinite. Due to the impurities contained in these raw materials, the present study uses
Mat. Res.. Publicado em: 24/01/2019