Optimization of gypsum and slag contents in blended cement containing slag

Sun, Huaqiang; Qian, Jueshi; Yang, Yalun; Fan, Chuanhe; Yue, Yanfei

doi:10.1016/j.cemconcomp.2020.103674

Cited by 79 publications

(9 citation statements)

References 55 publications

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“…Special focus should also be paid to the combined effect of slag and other dispersed additives on the properties of composites. Fly ash, nanosilica, lime, and gypsum, together with slag, improve the individual properties of composites based on them [39][40][41][42].…”

Section: Holding Time Daysmentioning

confidence: 99%

Nano-Modified Vibrocentrifuged Concrete with Granulated Blast Slag: The Relationship between Mechanical Properties and Micro-Structural Analysis

et al. 2022

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Currently, in civil engineering, the relevant direction is to minimize the cost of the manufacture of the hollow structures of annular sections, as well as their construction and installation efficiency. To optimize the costs associated with building products and structures, it is proposed to apply the technology of vibrocentrifugation, to reconsider and comprehensively approach the raw materials for the manufacture of such products and structures. The purpose of this study is a theoretical substantiation and experimental verification with analytical numerical confirmation of the possibility of creating improved variotropic structures of vibrocentrifuged concrete nano-modified with ground granulated blast-furnace slag. The study used the methods of electron microscopy, laser granulometry, and X-ray diffraction. Slag activation was carried out in a planetary ball mill; samples were prepared on a special installation developed by the authors—a vibrocentrifuge. The optimal and effective prescription–technological factors were experimentally derived and confirmed at the microlevel using structural analysis. The mathematical dependencies among the composition, macrostructure, microstructure, and final properties of vibrocentrifuged concrete nano-modified by slag are determined. Empirical relationships were identified to express the variation of some mechanical parameters and identify the relationship between them and the composition of the mixture. The optimal dosage of slag was determined, which is 40%. Increases in strength indicators ranged from 16% to 27, density—3%.

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Section: Holding Time Daysmentioning

confidence: 99%

Nano-Modified Vibrocentrifuged Concrete with Granulated Blast Slag: The Relationship between Mechanical Properties and Micro-Structural Analysis

et al. 2022

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“…In ordinary Portland cement, gypsum was added to relieve the hydration process of tricalcium aluminate (C 3 A) and prevent the occurrence of setting flash. , Several theories have been proposed on the mechanism of inhibition effect of gypsum on C 3 A, principally a covering layer (AFt or other hydrated products) and the adsorption effect of sulfate ions on the active sites inhibiting the further dissolution. , Scrivener and Quennoz revealed that the addition of gypsum in the cementitious system with different alite/C 3 A ratios caused a different hydration behavior, promoting the hydration reactivity of alite and changing the microstructure of the C–S–H. , In blended cement, in addition to the presence of aluminate phases (C 3 A and C 4 AF) in the cement, the use of supplementary cementitious materials also introduces a large amount of aluminate phases, which result in a delay in the cement hydration process. In a word, the gypsum amount required to balance the aluminate phases should be modified according to the content, species, and characteristics of aluminates in the cement system. , “Ferrite phases” usually associate with a solid solution with a stoichiometric ratio of Ca 2 Fe 2– x Al x O 5 (0 ≤ x ≤ 1.4) existing in Portland cement . Huang pointed out that the Al/Fe ratio in ferrite phases and the gypsum content have a significant influence on the hydration progress of the ferrite phase .…”

Section: Introductionmentioning

confidence: 99%

“…In a word, the gypsum amount required to balance the aluminate phases should be modified according to the content, species, and characteristics of aluminates in the cement system. 14,15 "Ferrite phases" usually associate with a solid solution with a stoichiometric ratio of Ca 2 Fe 2−x Al x O 5 (0 ≤ x ≤ 1.4) existing in Portland cement. 16 Huang pointed out that the Al/Fe ratio in ferrite phases and the gypsum content have a significant influence on the hydration progress of the ferrite phase.…”

Section: ■ Introductionmentioning

confidence: 99%

Improvement of the Hydration Kinetics of High Ferrite Cement: Synergic Effect of Gypsum and C₃S–C₄AF Systems

Ke-chang

Shen

Yang

et al. 2021

ACS Sustainable Chem. Eng.

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High ferrite cement (HFC) has attracted widespread attention due to the low carbon footprint and energy consumption. Gypsum, one of the essential components in Portland cement, plays a crucial role in the performance development of the matrix. However, the effect of gypsum on the performance evolution of HFC is obscure and unpredictable owing to the transformation of mineral phase composition including C 4 AF and C 3 S. Understanding the effect of gypsum is of great significance to further optimize the performance development and promote the application of HFC. This work was designed to investigate the influence of gypsum on the hydration kinetics of mineral phases and early performance development of HFC. Based on the experiment results, the underlying mechanism was explored and the role of gypsum in HFC can be divided into three aspects: (1) it changes the dissolution−precipitation process of C 4 AF and the reaction environment (pH value); (2) it relieves the inhibition effect of Al 3+ ions from C 4 AF on the hydration of C 3 S; and (3) it enhances the hydration kinetics of C 3 S and the formation of ettringite. As a result, the early performance development of HFC was improved evidently and the role of gypsum revealed in our work is of great significance to promote the sustainable development of HFC.

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“…The amount of slag used was expressed as slag/quartz content, which was in the range of ~28-47%. In the study of the Sum et al [24], optimization of gypsum and slag content in blended cement containing slag was investigated. For these experiments, blast furnace slag was also used.…”

Section: Introductionmentioning

confidence: 99%

Waste Slag from Heating Plants as a Partial Replacement for Cement in Mortar and Concrete Production. Part I—Physical–Chemical and Physical–Mechanical Characterization of Slag

et al. 2020

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Numerous factors influence the complexity of environmental and waste management problems, and the most significant goal is the reuse of materials that have completed their “life cycle” and the reduction in the use of new resources. In order to reduce impact of waste slag on the environment, in the present study, waste slag, generated in heating plants after lignite combustion, was characterized in detail and tested for application as a replacement for cement in mortar or concrete production. For physical–chemical characterization of slag, different experimental and instrumental techniques were used such as chemical composition and determination of the content of heavy metals, investigation of morphological and textural properties, thermal analysis, X-ray, and infrared spectroscopy. Physical–mechanical characterization of slag was also performed and included determination of activity index, water requirement, setting time and soundness. A leaching test was also performed. Presented results show that waste slag may be used in mortar and concrete production as a partial cement replacement, but after additional combustion at 650 °C and partial replacement of slag with silica fume in the minimal amount of 12%. The maximal obtained cement replacement was 20% (17.8% slag and 2.2% of silica fume).

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Optimization of gypsum and slag contents in blended cement containing slag

Cited by 79 publications

References 55 publications

Nano-Modified Vibrocentrifuged Concrete with Granulated Blast Slag: The Relationship between Mechanical Properties and Micro-Structural Analysis

Nano-Modified Vibrocentrifuged Concrete with Granulated Blast Slag: The Relationship between Mechanical Properties and Micro-Structural Analysis

Improvement of the Hydration Kinetics of High Ferrite Cement: Synergic Effect of Gypsum and C₃S–C₄AF Systems

Waste Slag from Heating Plants as a Partial Replacement for Cement in Mortar and Concrete Production. Part I—Physical–Chemical and Physical–Mechanical Characterization of Slag

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Optimization of gypsum and slag contents in blended cement containing slag

Cited by 79 publications

References 55 publications

Nano-Modified Vibrocentrifuged Concrete with Granulated Blast Slag: The Relationship between Mechanical Properties and Micro-Structural Analysis

Nano-Modified Vibrocentrifuged Concrete with Granulated Blast Slag: The Relationship between Mechanical Properties and Micro-Structural Analysis

Improvement of the Hydration Kinetics of High Ferrite Cement: Synergic Effect of Gypsum and C3S–C4AF Systems

Waste Slag from Heating Plants as a Partial Replacement for Cement in Mortar and Concrete Production. Part I—Physical–Chemical and Physical–Mechanical Characterization of Slag

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Improvement of the Hydration Kinetics of High Ferrite Cement: Synergic Effect of Gypsum and C₃S–C₄AF Systems