Enhancing the performance of MgO-activated slag-fly ash mixes by accelerated carbonation

Dũng, Nguyễn Tiến; Hooper, Thomas J. N.; Unluer, Cise

doi:10.1016/j.jcou.2020.101356

Cited by 15 publications

(8 citation statements)

References 59 publications

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“…The compactness of the alkali-activated blast furnace slag powder is improved when more dosage of MgO is added. This is attributed to the fact that the hydrated magnesium silicate gel formed by MgO and water can cover on the surface of the hydrated calcium silicate gel and fill the pore structure of the hydration products [ 42 , 43 ]. Moreover, as discovered in Figure 7 , the hydration products are more compact when the curing age is higher.…”

Section: Resultsmentioning

confidence: 99%

The Influence of CaO and MgO on the Mechanical Properties of Alkali-Activated Blast Furnace Slag Powder

et al. 2022

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CaO and MgO are both reported as effective activators for blast furnace slag. However, the synergistic effect of these two components on the mechanical properties of alkali-activated blast furnace slag remains unclear. In this study, the flexural and compressive strengths of alkali-activated blast furnace slag powder with MgO and CaO range from 0% to 30% by the mass ratio of alkali-activated blast furnace slag powder are investigated. Moreover, the dry shrinkage rate of alkali-activated blast furnace slag powder is measured. One percent refractory fibers by volume of binder materials are added in the alkali-activated blast furnace slag. Some refractory fibers are treated with water flushing, meanwhile, some refractory fibers are directly used without any treatment. Finally, the scanning electron microscope, the thermogravimetric analysis curves and the XRD diffraction spectrums are obtained to reflect the inner mechanism of the alkali-activated blast furnace slag powder’s mechanical properties. The water-binder ratios of the alkali-activated blast furnace slag powder are 0.35 and 0.42. The curing ages are 3 d, 7 d and 28 d. The measuring temperature for the specimens ranges from 20 °C to 800 °C. Results show that the flexural and compressive strengths increase with the increased curing age, the decreased water-binder ratio and the addition of refractory fibers. The water-treated refractory fibers can improve the mechanical strengths. The mechanical strengths increase in the form of a quadratic function with the mass ratio of MgO and CaO, when the curing age is 3 d, the increasing effect is the most obvious. A higher water-binder ratio leads to an increasing the drying shrinkage rate. The activated blast furnace slag powder with CaO shows a higher drying shrinkage rate. The mechanical strengths decrease with the increasing testing temperature.

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Section: Resultsmentioning

confidence: 99%

The Influence of CaO and MgO on the Mechanical Properties of Alkali-Activated Blast Furnace Slag Powder

et al. 2022

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“…resonances, which is assigned as amorphous Q 4 moieties in a highly-linked aluminosilicate network (ASN) [42,98]. A small narrow resonance at -93 ppm can be observed in mixes 100S, 10Mg and 10Mg5Mk, which has previously been assigned as a small amount of crystalline Q 4 (3Al) in the ASN formed via decalcification [38,42,98]. 5Mg10Mk remains unchanged, much like the 27 Al data, due to the lack of crystalline C-(A)-S-H prior to carbonation.…”

Section: Solid-state Nmrmentioning

confidence: 90%

“…MgO increases the pH level of the medium, which can expedite the dissolution of slag, thus accelerating the reaction [35][36][37]. It was indicated that the CaO content and degree of reactivity of the reactive MgO are the two main factors in the dissolution of slag [34,38]. It was also revealed that the MgO plays a role in slag dissolution since it controls the secondary products such as hydrotalcite depending on the amount of available Al 3+ ion in the systems [39].…”

Section: Introductionmentioning

confidence: 99%

Hydration kinetics and performance of sodium carbonate-activated slag-based systems containing reactive MgO and metakaolin under carbonation

Aktürk

Abolfathi²,

Ulukaya³

et al. 2022

Cement and Concrete Composites

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“…The improvement in material drying shrinkage via fly ash was due to its filler effect, which reduced the content of reactants and reaction activity, resulting in a decrease in mechanical properties. The shrinkage reduction effect was more obvious when a larger amount of fly ash was added [31]. The improvement in material drying shrinkage via gypsum was due to the production of gypsum dihydrate, which can combine with a large amount of water to form a larger solid phase, and the formation of larger-sized dihydrate gypsum.…”

Section: The Influence Of Solution Temperaturementioning

confidence: 99%

Investigating Mechanical Properties of Alkali-Activated Slag Cementitious Material for Load-Bearing Layer of Sandwich Panels

Zhu,

Qu,

Huang

et al. 2023

Materials

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The research presented in this paper is about the mechanical properties of fiber-reinforced alkali-activated slag cementitious sandwich panels with different types and amounts of admixtures. The mechanical properties, drying shrinkage properties, and micro-morphology were used to determine the optimal ratio of the admixtures. The results show that the alkali-activated slag sandwich panels have the characteristics of light weight, high strength and excellent thermal insulation, and the factors such as magnesium oxide, expansion agent and solution temperature have significant influence on their mechanical properties and dry shrinkage. This paper provides a theoretical basis and experimental data for the preparation process and application of alkali-activated slag sandwich panels.

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Enhancing the performance of MgO-activated slag-fly ash mixes by accelerated carbonation

Cited by 15 publications

References 59 publications

The Influence of CaO and MgO on the Mechanical Properties of Alkali-Activated Blast Furnace Slag Powder

The Influence of CaO and MgO on the Mechanical Properties of Alkali-Activated Blast Furnace Slag Powder

Hydration kinetics and performance of sodium carbonate-activated slag-based systems containing reactive MgO and metakaolin under carbonation

Investigating Mechanical Properties of Alkali-Activated Slag Cementitious Material for Load-Bearing Layer of Sandwich Panels

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