Preparation and characterization of coal gangue geopolymers

Cheng, Yi; Ma, Hui; Chen, Hongyu; Wang, Jiaxin; Shi, Jinjie; Li, Zonghui; Yu, Mao-Hong

doi:10.1016/j.conbuildmat.2018.07.220

Cited by 144 publications

(46 citation statements)

References 34 publications

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“…Previous studies on coal mining waste have demonstrated the potential for its use in alkali-activated material since it is rich in silicon and aluminum (6)(7)(8). However, pre-treatment processes are required (6,9). The aim of this research was to evaluate the influence of three different wastes on the mechanical performance and microstructural development of AAM, since the chemical, physical and mineralogical characteristics play an important role in this regard (44).…”

Section: Discussionmentioning

confidence: 99%

“…The FTIR transmission spectra are shown in Figures 11, 12 and 13. The presence of the broad band for O-H asymmetric stretching (3000-3700 cm −1 ) and the H-O-H deformation band (1600 cm −1 ), indicate chemically-bound water, which is associated with the formation of hydrated compounds (9,45). The broad band between 800 cm −1 and 1200 cm −1 is assigned to the asymmetric stretching vibration of Si-O-T (T is Al or Si).…”

Section: Pastes: Microstructural Analysismentioning

confidence: 99%

“…The main chemical compounds are SiO 2 and Al 2 O 3 , with traces of Fe, S, Ca and Mn (6)(7)(8). Some aluminosilicates are also present in the mineral phases, with little or no reactivity, and pre-treatment processes can promote more amorphous phase formation and less crystalline products (6,9). These characteristics can enhance the potential for coal gangue to be used in the production of construction materials.…”

Section: Introductionmentioning

confidence: 99%

“…Researchers have noted that it is necessary to include a secondary material, either to increase the calcium content of the alkaline medium (18) or to increase the aluminum content (19). A combination of NaOH and Na 2 SiO 3 , or addition of Ca(OH) 2 can provide an alkaline medium for coal gangue alkali-activated cement (9,20). Cheng et al (9) ensured early strength by using Portland cement as a source of CaO.…”

Section: Introductionmentioning

confidence: 99%

“…A combination of NaOH and Na 2 SiO 3 , or addition of Ca(OH) 2 can provide an alkaline medium for coal gangue alkali-activated cement (9,20). Cheng et al (9) ensured early strength by using Portland cement as a source of CaO.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Influence of different sources of coal gangue used as aluminosilicate powder on the mechanical properties and microstructure of alkali-activated cement

2019

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Coal mining wastes are associated with serious environmental problems; they have potential as building materials, including alkali-activated cement. In this study, the effect of different coal mining wastes on the mechanical properties and microstructural development of alkali-activated materials (AAMs) was evaluated through XRD, SEM and FTIR spectroscopy. Different alkali-activated compounds were produced; the alkaline solution was composed of NaOH+Na2SiO3. The results obtained using the calcined coal sludge showed excellent mechanical performance, with compressive strength higher than 60 MPa. However, addition of metakaolin and ordinary Portland cement was necessary to increase the mechanical performance of calcined coal gangue materials. The formation of N-A-S-H gel and the incorporation of iron ions into the cementitious matrix were evidenced. Ultrasonic pulse velocity indicated the early polymerization during the reaction processes. The study verified that the different characteristics of the wastes influence the performance of alkali-activated materials.

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Section: Discussionmentioning

confidence: 99%

Section: Pastes: Microstructural Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Influence of different sources of coal gangue used as aluminosilicate powder on the mechanical properties and microstructure of alkali-activated cement

2019

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Engineering performance of reinforced lightweight geopolymer concrete beams produced by ambient curing

Öztürk

2021

Structural Concrete

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The use of lightweight concrete can provide specific advantages that are favoring for mitigating seismic risk in building design. On the other hand, a significant reduction of carbon footprint could be possible through the use of geopolymer concrete. However, geopolymer concrete is mostly assessed through small specimens without reinforcement elements. This paper aims to couple the advantage of lightweight mixtures and ambient-cured geopolymerization in reinforced beams. To do this, engineering performance of reinforced lightweight geopolymer concrete was extensively investigated with different aspects. In mixtures, pumice and volcanic tuff aggregates were used with an appropriate gradation. Flexural strength, deflection capacities, initial stiffness, ductility, and energy dissipation capacity of reinforced geopolymer beams were investigated with the proposed configuration. Compressive strength and unit weight of the developed mixtures were also evaluated to meet design requirements for lightweight concrete. Results indicated that certain engineering properties (energy dissipation capacity and initial stiffness) of developed lightweight geopolymer concrete were considerably comparable with lightweight Portland cement-based concrete. Although compressive strength and unit weight of the developed geopolymer mixtures were satisfying, microstructural analysis indicated a weak bonding behavior between paste and lightweight aggregates.

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Experimental study on bond performance between deformed steel bar and coal gangue concrete

Wen

Gao

Huo

et al. 2022

Structural Concrete

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Coal gangue concrete (CGC), a great low cost and environment-friendly material, is considered to be the most effective substitute for normal concrete. The bond performance of steel bar embedded in CGC determines the feasibility of using CGC as structure material. So, this study presents an experimental program to investigate the bond strength of steel bar embedded in CGC compared to the one in normal-aggregate concrete. The experimental program contains 75 specimens that are tested using the pull-out test. In this study, coal gangue coarse aggregate replacement ratios (0%, 25%, 50%, 75%, and 100%), water-cement ratio (0.50, 0.45, and 0.40), and rebar diameters (14 mm, 16 mm, and 18 mm) were considered to analyze the variation law of bond strength. The test results show that the bond strength increased slightly with the decrease of water-cement ratio. The bond strength decreased slightly with the increase the aggregate replacement ratio if the replacement ratio was less than 50%. In contrast, the bond strength decreased significantly when the aggregate replacement ratio was more than 50%. In addition, the bond strength increases first and then reduces with increasing of bar diameters. Lastly, a new model of predicting the bond strength between the deformed steel bar and coal gangue concrete was proposed in this study because the widely used prediction models for the bond strength were not suitable for the coal gangue concrete.

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Preparation and characterization of coal gangue geopolymers

Cited by 144 publications

References 34 publications

Influence of different sources of coal gangue used as aluminosilicate powder on the mechanical properties and microstructure of alkali-activated cement

Influence of different sources of coal gangue used as aluminosilicate powder on the mechanical properties and microstructure of alkali-activated cement

Engineering performance of reinforced lightweight geopolymer concrete beams produced by ambient curing

Experimental study on bond performance between deformed steel bar and coal gangue concrete

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