Characterization and Hydration Mechanism of Ammonia Soda Residue and Portland Cement Composite Cementitious Material

Xu, Dong; Fu, Pingfeng; Wen, Ning; Li, Keqing

doi:10.3390/ma14174794

Cited by 9 publications

(6 citation statements)

References 33 publications

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“…FA used was classified as a kind of low-calcium fly ash, with a similar X-ray result compared with the study of Zhang et al [ 22 ], which also presented a spherical morphology. As for the used ASR, compared with the study of Xu et al [ 23 ], NaCl or CaCl 2 cannot be detected by X-ray, showing a lower content of chloride. In contrast, the main components of ASR from soda ash companies tested by the Axios PW4400 wavelength dispersive X-Ray fluorescence spectrometer are calcium carbonate, gypsum and magnesium hydrate ( Table 1 ).…”

Section: Role Of Fly Ash In Moc Pastesmentioning

confidence: 84%

Eco-Sustainable Magnesium Oxychloride Cement Pastes Containing Waste Ammonia Soda Residue and Fly Ash

et al. 2022

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Magnesium oxychloride cement (MOC), a type of special construction material, has drawn much research attention in solid waste utilization and environmental protection due to its eco-friendly production. Ammonia soda residue (ASR), a by-product generated from sodium carbonate manufacturing, is one of the industrial wastes that can be recycled in MOC systems. However, ASR exhibits adverse effects on the fresh performance and volume stability of MOC pastes. This paper aims at improving the properties of ASR-MOC by introducing fly ash (FA), solid waste from the power industry. Firstly, the roles of FA in MOC pastes are evaluated and analyzed. Then, three substitution ratios of FA (33.3%, 50% and 66.7% in weight) for ASR are designed for MOC pastes with 10% to 40% industrial wastes. Flowability, setting, strength and expansion of all mixtures were experimentally studied. Furthermore, X-ray diffraction (XRD) and scanning electron microscope (SEM) approaches were adopted to illustrate the microstructure changes. Results show that by adding different amounts of FA, the inferior flowability of MOC caused by ASR can be improved by 6–23%, the setting process can be prolonged by 30–55% and the expansion ratio can be reduced by 14–66%. The intensity of characteristic peaks of 5-phase and Mg(OH)2, together with the degrees of crystallization in XRD curves, well explain the strength variation and volume stability of ASR-MOC pastes. According to the regulation of relative specification, up to 20% of solid wastes in weight (10% FA + 10% ASR) can be consumed, contributing greatly to the greener sustainable development of construction materials.

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Section: Role Of Fly Ash In Moc Pastesmentioning

confidence: 84%

Eco-Sustainable Magnesium Oxychloride Cement Pastes Containing Waste Ammonia Soda Residue and Fly Ash

et al. 2022

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“…This is because BFS is the main precursor in SR-BFS composite precursors, and the BFS decline means the decrease of active substances; the amount of gel products in the hydration reduces, resulting in strength reduction. Although the CaSO 4 in the SR can promote the formation of ettringite in the system (conducive to early strength growth) [32], and the CaCO 3 crystals in the SR also have a microaggregate effect (improving the structural compactness) [33], these effects did not play a decisive role in the strength development. According to Figure 5c, the compressive strength at each curing age decreased gradually with an increase in the water-binder ratio, which is consistent with that of cement-based materials.…”

Section: Compressive Strengthmentioning

confidence: 98%

“…Additionally, the higher content of SR in SGN8 led to the highest calcite content and the highest corresponding absorption peak intensity in this sample. The absorption peaks near 1640 cm −1 and 3440 cm −1 were caused by the H-O-H bond's bending and stretching vibrations, which were the crystal water's internal vibration absorption characteristics [33,47]. The crystal water mainly came from C-(A)-S-H gel, HC, and ET [33].…”

Section: Ftir Analysismentioning

confidence: 99%

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Mechanical Properties and Microstructure of Alkali-Activated Soda Residue-Blast Furnace Slag Composite Binder

et al. 2022

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This study prepared an alkali-activated soda residue (SR)-blast furnace slag (BFS) composite binder by adding a large amount of SR to the alkali-activated material system. Considering many factors, such as the Na2O content, ratio of SR to BFS and the water-binder ratio, the variation patterns in the new binder’s mechanical properties and its micro-evolution mechanisms were assessed. The results show that the compressive strength first grew and then dropped with the Na2O content, with an optimal level at 3.0%. At this level, the strength values of the 3d and 28d samples were 10.5 and 27.8 MPa, respectively, exceeding those in the control group without Na2O by 337.5 and 69.5%, respectively. As the Na2O admixture increased from 0 to 3%, the fluidity of the mortar decreased from 156 mm to 127 mm due to the high frictional resistance caused by the faster generation of hydration products, and the high water absorption of SR also led to reduced fluidity. The new binder’s hydration process mainly generated C-(A)-S-H gel, ettringite (ET), hydrocalumite (HC), calcium hydroxide (CH), and other crystalline hydrates. A 3% Na2O content inhibited the ET growth but significantly promoted the formation of uniformly distributed C-(A)-S-H gel and HC. Crystals grew in the pores or were interspersed in the gel, filling microcracks and significantly increasing the structure density and strength. Excessive Na2O (>3%) could promote the generation of non-uniformly distributed gel, producing more macropores in the matrix and reducing its strength. Additionally, the increased SR content was not conducive to C-(A)-S-H gel formation, but significantly promoted ET formation, which would inhibit strength development. This study provides a theoretical basis for replacing cement with this new binder in pavement bricks and other unreinforced products.

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“…Notably, it lacks heavy metals and polluting organic matter (Chen et al, 2022). Current utilization efforts mainly involve its incorporation into cement (Xu et al, 2021), mortar (Zhang et al, 2017), carbonized brick (Zhao et al, 2017), soil conditioning (Pan and Xu, 2017), cementitious materials and concrete (Xu et al, 2020), engineering soil (Gong et al, 2023), and as a component in flue gas desulfurization and adsorption (Peng and Liu, 1999;Rui et al, 2006). However, these methods have limitations in scale and efficiency, necessitating a comprehensive expansion of ammonia-alkali white mud utilization.…”

Section: Introductionmentioning

confidence: 99%

Study on characteristics of ammonia alkali white mud and mechanical properties of preparation of fluid solidified soil

Fu,

Li,

Zhang

et al. 2024

Front. Mater.

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To address the challenges posed by the significant quantity of ammonia-alkali white mud, this study explores the preparation of fluid solidified soil using ammonia-alkali white mud, mineral powder, and fly ash. The findings reveal that ammonia-alkali white mud primarily comprises sulfate, carbonate, and soluble chloride salt, with an alkaline solution and a well-developed pore structure. Optimal fluid solidified soil formulation, comprising 30% white mud, 30% salt mud, 25% mineral powder, 10% fly ash, and 5% calcium oxide, yields a slurry fluidity of 176 mm and a compressive strength of 3.98 MPa at 28 days. Microscopic analysis highlights AFt and C-S-H gel as the principal hydration products of fluid solidified soil. The fine particles of calcium carbonate in ammonia-alkali white mud fill the structural pores and intertwine with the hydration products, facilitating the formation of a dense structure, which constitutes the primary source of strength in fluid solidified soil. Furthermore, the heavy metal content of the solidified soil aligns with the first type of land use requirements outlined in the GB 36600-2018 standard, and the toxicity of the leaching solution adheres to the emission concentration limit stipulated by GB 8978-1996.

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Characterization and Hydration Mechanism of Ammonia Soda Residue and Portland Cement Composite Cementitious Material

Cited by 9 publications

References 33 publications

Eco-Sustainable Magnesium Oxychloride Cement Pastes Containing Waste Ammonia Soda Residue and Fly Ash

Eco-Sustainable Magnesium Oxychloride Cement Pastes Containing Waste Ammonia Soda Residue and Fly Ash

Mechanical Properties and Microstructure of Alkali-Activated Soda Residue-Blast Furnace Slag Composite Binder

Study on characteristics of ammonia alkali white mud and mechanical properties of preparation of fluid solidified soil

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