La activación alcalina de diferentes aluminosilicatos como una alternativa al Cemento Portland: cementos activados alcalinamente o geopolímeros

Torres-Carrasco, M.; Puertas, Francisca

doi:10.4067/s0718-50732017000200001

Cited by 85 publications

(63 citation statements)

References 27 publications

(30 reference statements)

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“…This represents an increase of up to 46% in compressive strength (at 28 days) with an OPC increase of only 5%. This is in agreement with the results reported by previous studies [8,[20][21][22] that associate the gain in strength to a greater densification of the cementing matrix promoted by the formation of C-A-S-H and (N,C)-A-S-H type "hybrid gels". An increase in strength on aging longer was also noted.…”

Section: Reaction Kinetics Of the Hybrid Cementsupporting

confidence: 93%

Alkali-Activated Hybrid Concrete Based on Fly Ash and Its Application in the Production of High-Class Structural Blocks

et al. 2020

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This article reports the production and characterization of a hybrid concrete based on the alkaline activation of a fly ash (FA) of Colombian origin, which was added with 10% Portland cement (OPC) in order to promote the compressive strength development at room temperature. The alkali-activated hybrid cement FA/OPC 90/10 was classified as a low heat reaction cement (type LH), according to American Society of Testing Materials, ASTM C1157; the compressive strength was of 31.56 MPa and of 22.68 MPa (28 days) at the levels of paste and standard mortar, respectively, with an initial setting time of 93.3 min. From this binder, a hybrid concrete was produced and classified as a structural type, with a compressive strength of 23.16 MPa and a flexural modulus of rupture of 5.32 MPa, at 28 days of curing. The global warming potential index (GWP 100), based on life cycle analysis, was 35% lower than the reference concrete based on 100% OPC. Finally, its use was validated in the manufacture of a solid block-type construction element, which reached a compressive strength of 21.9 MPa at 28 days, exceeding by 40.6% the minimum strength value established by the Colombia Technical Standard, NTC 4026 (13 MPa) to be classified as high class structural blocks.

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Section: Reaction Kinetics Of the Hybrid Cementsupporting

confidence: 93%

Alkali-Activated Hybrid Concrete Based on Fly Ash and Its Application in the Production of High-Class Structural Blocks

et al. 2020

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“…Las cenizas volantes con un bajo contenido en calcio y arcillas calcinadas (ej. metacaolin) son los precursores más comunes utilizados en la síntesis del geopolímero [6].…”

Section: Marco Teóricounclassified

“…Esto es debido, principalmente, a sus buenas prestaciones, a su buena relación calidad/ precio y a que las materias primas a partir de las cuales se fabrica pueden encontrarse prácticamente en todo el mundo. Sin embargo, el desarrollo de cementos alternativos al cemento Portland que se obtengan a través de procesos que supongan menores emisiones de gases contaminantes a la atmósfera y con un apreciado ahorro energético, constituye una línea de investigación prioritaria y de gran interés a escala mundial [6]. Una activación alcalina de distintos residuos cerámicos con una mezcla de hidróxido de sodio (NaOH) y silicato de sodio (Na 2 SiO 3 ) en concentración de 6M y reporto una resistencia a la compresión de 13 MPa.…”

Section: Marco Teóricounclassified

Propuesta para el diseño de cemento alternativo basado en residuos de ladrillo de arcilla roja activados alcalinamente

Celis-Vergel

2019

Sostenibilidad, Tecnología y Humanismo

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Los cambios constantes que han sufrido los materiales en la construcción se apegan a necesidades de su contexto, es por ello que el concreto es uno de los materiales más importantes para las obras civiles, y su evolución es primordial para la mejora continua y poder ayudar a la comunidad en aprovechar sus beneficios, es por ello que el propósito de esta investigación que se formula desde su primera etapa es poder proponer un concreto a base de los diferentes residuos de los ladrillo de arcilla para la realización de pruebas de laboratorio y así poder saber cómo se comporta el concreto cuando se le añade este material reciclado, con esto podemos esperar resultados que se pudieran aprovechar en varios contextos y así disminuir o mejorar características que ayudan a elevar los costos de producción de este material.

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“…Nowadays, OPC is the main material that is used in the construction industry [1], and its production has a considerable impact on the emission of greenhouse gases into the environment, representing between 5-7% of CO 2 emissions worldwide. In addition, cement plants consume high amounts of primary energy, which is estimated in 3% of the worldwide consumption [2]. These CO 2 emissions are caused by the combustion that is necessary to reach temperatures of around 1450 • C (30-35%) and the decarbonation or decomposition of limestone to produce clinker (50-60%) and the materials transport (around 10%) [3].…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of a Hybrid Cement Based on Fly Ash, Metakaolin and Portland Cement Clinker

2020

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Hybrid cement has become one of the most viable options in the reduction of CO 2 emissions to the environment that are generated by the cement industry. This could be explained by the reduction of the content of clinker in the final mixture and substitution of the remaining percentage with supplementary cementitious materials with the help of an alkaline activation. Following that, properties that are provided by an Ordinary Portland Cement and of a geopolymer are mixed in this type of hybrid material and could be achieved at room temperature. Thereafter, the main objective of this research was to synthesize hybrid cements reducing the clinker content of Portland Cement up to 20% and use metakaolin and fly ash as supplementary cementitious materials in different proportions. The mixtures were alkaline activated with a mixture of sodium silicate and sodium hydroxide, calculating the amounts according to the percentage of Na 2 O that is present in each of the activators. The samples were then characterized using Compressive strength, X-ray diffraction, Fourier Transform Infrared Spectroscopy, and Scanning Electron Microscopy with energy-dispersive X-ray spectroscopy. The results indicated that the hybrid cements have similar mechanical properties than an Ordinary Portland Cement, and they resulted in a dense matrix of hydration products similar to those that are generated by cements and geopolymers.Materials 2020, 13, 1084 2 of 15 that serve as partial or total substitutes are called supplementary cementitious materials (SCMs) [4], of which the best known are ground granulated blast furnace slag (GGBFS), fly ash (FA), silica fume (SF), and calcined clays. The use of these materials can be a viable solution for the reduction of CO 2 emissions [5]. Current cement consumption is projected to be double by 2050, and the use of these materials could highly reduce CO 2 emissions to the environment [4]. Following that, a model of binders is currently being studied, which consists of adding to the mix of supplementary materials a very low portion of CaO in the form of clinker, to obtain a setting at room temperature [1]. During the past decades, alkali-activated and blended cement have attracted strong interest worldwide, due to their advantages of low energy cost, high strength, good durability, and sustainability. A major incentive for the further development of such cements is generated by the great quantity of annual generation of wastes, which cause a need to find new uses for them. The main raw materials used for this proposal are FA, GGBFS, and metakaolin (MK), in which activators, like water glass and sodium hydroxide, are used. Among the alkaline cements, two large groups are known: (a) calcium and silicon-rich activated materials (Me 2 O-MeO-Al 2 O 3 -SiO 2 -H 2 O system); here, the activation of GGBFS (SiO 2 + CaO > 70%) corresponds, under relatively mild alkalinity conditions [6]. A hydrated calcium aluminosilicate gel (C-A-S-H) is the main hydration product generated, similar to the gel generated in the hydrati...

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La activación alcalina de diferentes aluminosilicatos como una alternativa al Cemento Portland: cementos activados alcalinamente o geopolímeros

Cited by 85 publications

References 27 publications

Alkali-Activated Hybrid Concrete Based on Fly Ash and Its Application in the Production of High-Class Structural Blocks

Alkali-Activated Hybrid Concrete Based on Fly Ash and Its Application in the Production of High-Class Structural Blocks

Propuesta para el diseño de cemento alternativo basado en residuos de ladrillo de arcilla roja activados alcalinamente

Synthesis and Characterization of a Hybrid Cement Based on Fly Ash, Metakaolin and Portland Cement Clinker

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