Consequently, the "pessimum effect" of slag fineness on the ASR-induced expansion of AAS mortars was due to a combination of reaction rate of slag, porosity, shrinkage, strength, amount of dissolved reactive silica from aggregates, and the competition between the reaction of slag and reactive silica as well as the amount of ASR gel and ...
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The exposed slices were immersed in isopropanol for 7 d to arrest the reaction of slag following the standard [33], and then dried in a vacuum oven at 20 °C until constant weight. Some of the slices were crushed into 4–6 mm pieces for MIP tests using a Micrometrics PoreSizer 9500. ... Alkali metal ion (Na) The Na in efflorescence products ...
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When glass is used as supplementary cementitious materials (SCM), the high alkali metal content in the glass can react with reactive silica in aggregates and subsequently cause deleterious ASR ...
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In addition, You et al. [26] demonstrated that as the slag content increased in alkali-activated slag/steel slag pastes, the content of Al 2 O 3 increased from 12 % to 16 % and the amounts of K +, Ca 2 ... S 2− and HS − ions in simulated pore solution of slag-based AAM react with Fe to form Fe-S complexes and reduce the stability of the ...
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The carbonation reaction of steel slag is a process that utilizes CO 2 to react with calcium and magnesium minerals present in the slag, ... These bacteria are alkali-resistant bacteria, playing a catalytic and leading role in the carbonation process [82], [83]. On one hand, they catalyze carbonation reactions by secreting enzymes, and on the ...
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If the alkali-activated slag-steel slag (AASS) binder can obtain similar properties to the AASF binder, the recycling of SS will be realized. Meanwhile, the undersupply of slag and FA for the production of AAMs would also be solved. However, the application of SS to the preparation of AAMs is rarely studied. ... The reaction of slag accelerated ...
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AAM-UHPC is mainly composed of hydration products generated by the reaction of steel slag powder and GGBFS powder interwoven to form a spatial network. ... Huo W., Song S., Zhang J., Yao K., Hu L. Efficient use of steel slag in alkali-activated fly ash-steel slag-ground granulated blast furnace slag ternary blends. Constr. Build. Mater. 2020 ...
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Increasing Ms increases the compressive strength and improves the pore structure, and it significantly increases the drying shrinkage of all samples. This study provides theoretical …
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Research has indicated that alkaline calcium ions generated during the hydration of steel slag can react with silicate ions present in siliceous materials to form C-S-H gel, ... This film effectively prevents direct contact between the alkali metal expansion components of the steel slag and water, thereby achieving the intended control of ...
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This study aims to investigate the valorization of high-volume converter steel slag in alkali activated GGBS systems by using a combined alkali activation and carbonation. To study the influences of activator dosage on GGBS-CSS mixtures during alkali activation and carbonation reaction processes, sodium hydroxide was selected with the ...
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Steel slag (SS) exhibits low hydration activities and expansive phases, which should be pretreated prior to using as binding materials. Thus, these properties of SS were …
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One promising approach is based on aluminosilicate raw materials such as blast furnace slag derived from the iron making process, which can be reacted with an alkali source to produce …
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Blast furnace slag is a by-product of steel production and is widely used in the concrete industry. Its main components are CaO, SiO 2, Al 2 O 3 and MgO. In comparison to cement, it contains less CaO, and more SiO 2 and Al 2 O 3, with various ranges of MgO.Blast furnace slag belongs to the group of precursors that can react with an alkali solution to give a …
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Song [24] attempts were made to alkali-activate fly ash-steel slag, and it was found that when the substitution rate of steel slag for fly ash was between 20%− 50%, the compressive strength at 28 days decreased significantly with increasing substitution rate. ... which provides a calcium source for the reaction. Mixing steel slag powder with ...
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They found that alkali-activated steel slag has a faster reaction, fewer hydration products, poorer crystallization of Ca(OH) 2, a lower Ca/Si ratio, and a similar Al/Si ratio of gels than Portland cement .
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The initial stages of hydration mainly consist of a reaction with alkali metal hydroxides, and the later stage is mainly an experimental reaction with Ca(OH) 2 . The final hydration product after slag activation is similar to the cement C-S-H, but the Ca/Si ratio of the slag hydration product is lower. ... Therefore, the reaction rate of steel ...
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In the present study, the electric arc furnace carbon or stainless steel slag (EAF) and secondary metallurgical slag such as ladle furnace basic slag (LS) were used as precursors in alkali-activation process to obtain chemically stable solid manufacts.
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Alkali-activated binders refer to any binder material formed through the alkali-induced reaction of silica, alumina, and calcium-containing sources. Geopolymerization is characterized by the chemical reaction between aluminosilicate materials and alkali metal silicates, occurring within highly alkaline environments.
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Moreover, it can be produced using industrial waste residues, such as fly ash and steel slag. However, alkali slag cement exhibits cracks at early shrinking, thereby restricting its application and further developments [5,6,7]. Hence, its shrinkage performance, mechanical properties, and compliance with the national standards for the setting ...
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This paper presents a characterization analysis of alkali-activated steel slag. The effect ratio of steel slag and ferronickel slag which are the precursor ma-terials on the compressive strength …
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Atmospheric CO₂ rapidly reacts with steel slag rich in Ca/Mg Hydroxide, producing permanent carbonate minerals. Measurement, Reporting, and Verification (MRV) is at the core of what Alkali Earth does in directly …
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Global research interest has grown in the role of sulfides on the passivation of embedded carbon-steel reinforcement of activated slag materials. As slag reacts and dissolves, so does the CaS phases present in slag, releasing reduced sulfur species (HS −, S n 2−) into the pore solution. 33-37 Alkali-activated slag materials are ...
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In the present study, the electric arc furnace carbon or stainless steel slag (EAF) and secondary metallurgical slag such as ladle furnace basic slag (LS) were used as precursors in an...
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Coal gasification slag is an inevitable by-product of the coal gasification process. This paper explored the feasibility of using activators (calcium hydroxide, sodium hydroxide, calcium sulfate, sodium sulfate) to promote the pozzolanic activity of milled coal gasification coarse slags (MCS), and analyzed the effect of alkali and sulfate activators on the hydration …
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Combined with equations (3−1) to (3−5), it is known that the reaction between the alkali components enhances the alkalinity of the alkali slag slurry system, promoting the destruction, decomposition, and reaggregation of the slag vitreous body, thus making AASC have higher mechanical strength and shorter setting time [21].
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The presence of a high amount of MnO in the slag does not significantly affect the corrosion process of steel under the conditions tested. Mass transport through the mortar to the metal is impeded with increasing exposure time; this is associated with refinement of the pore network as the slag continued to react while the samples were immersed.
WhatsApp: +86 18221755073Alkali-activated materials, as one of the promising substitutes to Portland cementitious binders, are considered environmentally friendly [1] because of the resourceful repurposing of industrial byproducts (e.g., blast-furnace slag and coal fly ash) into clinkerless binders.Alkali-activated slag (AAS), as the most studied alkali-activated material, shows …
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1. Introduction. Alkali-activated cements (AACs), generally regarded as clinker-free cements, are synthesized through the reaction between solid aluminosilicate precursors with latent hydraulic or pozzolanic properties and alkaline activator solutions [1].Numerous investigations have confirmed that metallurgical waste slags such as steel slag [2, 3] and …
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Simultaneous utilization of mine tailings and steel slag for producing geopolymers: Alkali-hydrothermal activation, workability, strength, and hydration mechanism ... the absence of the exothermic peak for sample G15–0 indicated that the hydration reaction of slag was extremely slow and the production of reactants with cementitious properties ...
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In this study, slag (GGBS) was utilized as the primary material, phosphogypsum (PG) as the sulfat activator, and carbide slag (CS) and steel slag (SS) as the alkali activators …
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نشانی: شماره 1688، جاده شرقی گاوک، منطقه جدید پودونگ، شانگهای، چین.
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