1 1 The Role of Zinc in Metakaolin-Based Geopolymers 2 Lei Wang1,2,3, Daniel A. Geddes1, Brant Walkley1,4, John L. Provis1, Viktor Mechtcherine3, 3 Daniel C.W. Tsang2, * 4 5 1 Department of Materials Science and Engineering, The University of Sheffield, Sir Robert Hadfield 6 Building, Mappin St, Sheffield S1 3JD, United Kingdom. 7 2 Department of Civil and …
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Specimens with metakaolin as a replacement for Portland cement present higher compressive strength and greater resistance to efflorescence; however, the addition of more than 20% …
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The Blaine value of metakaolin is higher in comparison to PCC. While the Blaine value of PCC is 3670 cm 2 /g, the Blaine value of 20% metakaolin–substituted cement increases up to 4752 cm 2 /g (Table 2). Because the specific gravity of metakaolin is smaller than PCC, it reduces the specific gravity of 20% metakaolin–substituted cement.
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Due to the high pozzolanic reactivity and small fineness, metakaolin plays a considerable role in the pore structure evolution of cementitious materials through a number of physical and chemical effects.
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The usage of metakaolin in Portland cement-based materials is very common, but there are only very a few studies on metakaolin blended MPC [25], [26], [27]. Judged from the previous results, metakaolin can significantly increase the strength, prolong the setting time and improve the water resistance of MPC [22].
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Roles of metakaolin in magnesium phosphate cement: Effect of the replacement ratio of magnesia by metakaolin with different particle sizes. ... The usage of metakaolin in Portland cement-based materials is very common, but there are only very a few studies on metakaolin blended MPC [25], [26], [27].
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While most research focuses on the effect of SCMs on cement hydration, the role of the cement on SCM pozzolanicity should also be acknowledged. Work by Cyr et al. [77] has shown, for example, that the pozzolanicity of metakaolin is reduced in low-C 3 A cements.
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As a starting material for the production of the geopolymer metakaolin, slag or alumosiliceous fly ash are commonly used [7,8]. Metakaolin is a dehydroxylated form of the clay mineral kaolinite and its structure is based on an amorphous (non-crystalline) aluminosilicate network, which can be activated by a base to form a corresponding geopolymer.
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TG results showed that metakaolin promoted the formation of additional hydration products at 3d, implying that the pozzolanic reaction of metakaolin was accelerated. MIP …
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Aging of Portland cement, due to its reaction with moisture and atmospheric CO 2 prior to regular use, has the potential to severely impair its hydration reactivity. The effectiveness of using metakaolin to improve the properties of aged Portland cement exposed to a laboratory conditions (RH=65 %, 20 °C) as well as the associated mechanism are studied.
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Sensible thermal energy storage using concrete as a storage medium is a promising technology that helps minimize energy in power plant. The purpose of this study is to evaluate the potential benefits of metakaolin (MK) as a partial substitute for fly ash-based geopolymer for heat resistance. As a partial substitute (5 and 20 wt.%) for fly ash (FA), nine …
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Metakaolin had a low influence on reducing the deterioration of the compressive strength of basalt concrete up to 300 °C. Otherwise, it negatively influenced the compressive strength at 500 °C; it explained the role of metakaolin on cement gel dehydration in reducing the compressive strength.
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AbstractOnce sulfates become limited, the interaction of limestone with metakaolin (MK) is initiated, resulting in the formation of carboaluminates in a blended cement system. In this study, two different types of MKs (sourced from coal mining residue and ...
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The optimization of metakaolin (MK) in pre-cured geopolymer concrete involves developing predictive models to capture the interplay of various influencing factors and guide …
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The hydration reactions of the cement are very complex and there is no single method that determines these reactions. For this reason, a few supplement techniques for various properties and hydration reactions of Portland–composite cement, which are silica fly ash and limestone, containing metakaolin were used in present study. In the first step, the physical, …
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The role of metakaolin (MK) in enhancing the strength of concrete is reviewed and the principal mechanisms identified. ... However, although greater in the metakaolin-cement concretes than the ...
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metakaolin in concrete positively influences durability properties such as penetrability (water absorption, gas permeability and chloride ingress), and helps mitigate ASR.
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Therefore, this study investigates the role of carbonates on the hydration, strength and durability in Portland-metakaolin cement. A total of six blends comprising three carbonate (limestone, dolomite and magnesite) and three non-carbonate (fly ash, quartz and metakaolin) sources were selected to determine the deviations arising in the ...
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The major oxide composition of both Portland cement (PC) and metakaolin (MK) is presented in Table 1. The true densities of the Portland cement and metakaolin, determined by a Helium Pycnometer, were 3.18 and 2.53 g/cm 3, respectively.
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DOI: 10.1016/J.CEMCONCOMP.2021.103999 Corpus ID: 233567290; The role of metakaolin in pore structure evolution of Portland cement pastes revealed by an impedance approach @article{Cai2021TheRO, title={The role of metakaolin in pore structure evolution of Portland cement pastes revealed by an impedance approach}, author={Rongjin Cai and Zushi Tian and …
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Corrosion of concrete sewer pipes by sulfuric acid attack is a problem of global scope. The current paper aims at evaluating two supplementary cementing materia
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Hence, there is an increased need for alternate binder systems with the ability to reduce the effects of chloride attack in concrete. This paper presents a critical review of the …
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Chloride binding is a complex phenomenon in which the chloride ions bind with hydrated Portland cement (PC) phases via physical and chemical mechanisms. However, the current utilization of clays as (Al)-rich …
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Metakaolin improves the mechanical properties and durability of MPC. Metakaolin decreases the early-term hydration heat of MPC and the total porosity. Mechanisms of …
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Title: Metakaolin in Concrete: The Role of Alumina Author(s): Michael Thomas Publication: Web Session Volume: Issue: Appears on pages(s): Keywords: DOI: Date: 10/17/2021 Abstract: Data are presented from a number of studies on the durability of mortar and concrete containing metakaolin (MK), a calcined high-purity kaolin clay (kaolin: Al2O3·2SiO2·2H2O).
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Properties of the alkali activated slag cement with a modifying additive—metakaolin—added in a quantity of 10 % by mass are reported and discussed. ... O., Kavalerova, E. (2015). Role of Metakaolin on Lowering pH of the Alkali Activated Cement Concrete in Barrier Application. In: Scrivener, K., Favier, A. (eds) Calcined Clays for ...
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Metakaolin, produced by calcining kaolinite at high temperature, is a pozzolanic material, suitable to be used in concrete mixes. This paper reviews the research published on …
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Alsallami [63] found that the presence of 10%NMK in normal concrete played a vital role in reducing the deterioration due to the sulfates action. Zhang et al.found that nanometer metakaolin could improve the frost resistance [110, 134], acid rain erosion resistance [135] and electrical conductivity [118] of cement-based
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Role of recycled vehicle tires quantity and size on the properties of metakaolin-based geopolymer rubberized concrete. ... The workability and unit weight of metakaolin based geopolymer concrete reduced by introduction of recycled rubber to the mix. However, the reduction in the slump was more pronounced for mixes having coarse rubber particles ...
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As a low-carbon alternative to the traditional portland cement, geopolymers are produced via the alkali-activation of aluminosilicate precursor powders, normally metakaolin or fly ash. By eliminating the processes of limestone decomposition and high-temperature calcination during the cement manufacturing, the production of geopolymers could ...
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