Effects and mechanisms of slag reinforced coal gangue geopolymers

Q, H; Zhu, Hongguang; Chen, H Y; Yadong, Ni; Wang, T; Yang, Sen

doi:10.1088/1757-899x/474/1/012040

Cited by 3 publications

(3 citation statements)

References 13 publications

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“…Then in the EDS spectra, it is found that the product is mainly composed of elements such as C, O, Si, Al, and Ca, which is consistent with the results of the XRD spectra. It is inferred that the hydration products are between C-S-H and C-A-S-H or mixtures thereof, which is similar to the experimental results of Ma et al 12 . It can be further found by EDS spectroscopy that at the age of 7d (Fig.…”

Section: In Uence Of Curing Agessupporting

confidence: 89%

“…This is due to the fact that the content of Ca 2+ in the system is continuously increased with the increase of slag A-S-H gel crystals. Meanwhile, the high charge density of Ca 2+ ions drives gel precipitation to from the formation of the three-dimensional disordered mesh that lls the internal structure of the geopolymer 12 , and ultimately the compressive strength of the geopolymer is improved.…”

Section: Compressive Strengthmentioning

confidence: 99%

“…It is found that replacing part of the coal gangue with slag could accelerate the generation of C-S-(A)-H gel crystals, thereby re ning the internal structure, resulting in a signi cant increase in the compressive strength of the geopolymer 10,11 . For example, Ma et al suggested that when the slag substitution rate is increased to 20%, the compressive strength of geopolymer is much higher than that of P.O42.5 cement, which is gradually viewed as a substitute for cement 12 .…”

Section: Introductionmentioning

confidence: 99%

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Preparation of coal gangue based geopolymer and electrical conductivity studies

Zha,

Lv,

et al. 2024

Preprint

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Geopolymers are both an effective way to achieve solid waste utilization of coal gangue and an environmentally friendly alternative to ordinary Portland cement. At the same time, the rich ionic content of geopolymers gives them superior conductivity, which makes them potentially valuable for applications in a variety of fields such as nondestructive testing, ice and snow melting, and electromagnetic shielding. However, the influence of external factors on its conductivity is still unclear, which limits its wide application in construction. In this study, coal gangue and slag are used to prepare geopolymer under alkaline excitation conditions, and the influence laws of alkali equivalent, slag substitution rate, modulus and water-cement ratio on its consistency, compressive strength and resistivity are investigated, and the changing law of resistivity of specimens with the curing ages and water content are also explored. It is found that the compressive strength is affected by alkali equivalent, slag substitution rate, modulus and water-cement ratio. When the alkali equivalent, slag substitution rate, modulus and water-cement ratio are taken to 12%, 55%, 1.2, 5 or12%, 45%,1.2, 4 respectively, the compressive strength at 28 days could be more than 80 MPa. Resistivity is first decreased and then increased with increasing alkali equivalent, increasing slag substitution rate, or increasing modulus, and is decreased with increasing water-cement ratio, and all of them are increased with increasing curing ages. At the age of 7 days, it is most significantly affected by alkali equivalent, while after the age of 14 days, it is more significantly affected by modulus and slag substitution rate than alkali equivalent; the effect of water-cement ratio is smaller at different ages. In addition, the resistivity is shown to increase significantly with decreasing water content, and the resistivity is increased by nearly 5–6 orders of magnitude when the specimens are transformed from the surface-dry state to the dry state.

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Section: In Uence Of Curing Agessupporting

confidence: 89%

Section: Compressive Strengthmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Preparation of coal gangue based geopolymer and electrical conductivity studies

Zha,

Lv,

et al. 2024

Preprint

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High-capacity utilization of coal gangue as supplementary cementitious material, geopolymer, and aggregate: A review

Wu,

Chen,

Song

et al. 2024

Construction and Building Materials

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Activation Mechanism of Coal Gangue and Its Impact on the Properties of Geopolymers: A Review

et al. 2022

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Coal gangue is one of the industrial solid wastes that may harm the human body through the ecosystem for a long time. Using coal gangue in geopolymer preparation can effectively reduce cement output and meet the sustainability requirements. In this paper, the physical and chemical characteristics, including the heavy metal content, of coal gangue from different producing areas are described. Then, the mechanism of physical activation (mechanical and thermal activation), chemical activation, and compound activation of coal gangue are illustrated. The machinability, as well as the mechanical, microscopic, and toxicity consolidation properties of geopolymers prepared from coal gangue, are summarized and analyzed. The results indicate that the coal gangue geopolymers can have higher mobility and mechanical strength than cement-based composites by adjusting high calcium element material, alkali activator content, Na2SiO3 modulus, and curing condition. After physical activation, coal gangue is used in geopolymer preparation with a chemical activator (alkali excitation agent), which effectively forms a three-dimensional silicon aluminate polymer network. The pore structure is dense, the physical fixation and chemical bonding are strengthened, and the solidification and adsorption of heavy metal ions are improved. Further, it can also be applied to solidifying radioactive waste, which is following the future development direction.

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Effects and mechanisms of slag reinforced coal gangue geopolymers

Cited by 3 publications

References 13 publications

Preparation of coal gangue based geopolymer and electrical conductivity studies

Preparation of coal gangue based geopolymer and electrical conductivity studies

High-capacity utilization of coal gangue as supplementary cementitious material, geopolymer, and aggregate: A review

Activation Mechanism of Coal Gangue and Its Impact on the Properties of Geopolymers: A Review

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