Mechanical properties and microstructure evaluation of fly ash - Slag geopolymer foaming materials

Su, Lijuan; Fu, Guosheng; Li, Bing; Sun, Qi; Zhang, Xiangdong

doi:10.1016/j.ceramint.2022.03.081

Cited by 30 publications

(7 citation statements)

References 30 publications

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“…The loss of compressive strength was probably caused by the surplus replacement of FA with GGBFS, which has also been reported by Zhang et al 10 . Su et al 12 . synthesized a kind of high‐porosity FA/GGBFS geopolymer foam using high FA content.…”

Section: Introductionsupporting

confidence: 65%

“…Xu et al 11 also developed a type of FA/GGBFS geopolymer foam, in which a GGBFS substitution of 40% was used. The compressive strength was merely about 50% of the one that has a comparable thermal conductivity produced by Zhang et al 10 The loss of compressive strength was probably caused by the surplus replacement of FA with GGBFS, which has also been reported by Zhang et al 10 Su et al 12 synthesized a kind of highporosity FA/GGBFS geopolymer foam using high FA content. It showed no significant improvement of compressive strength even in comparison to the FA-based geopolymer foam without the addition of GGBFS.…”

Section: Introductionmentioning

confidence: 58%

“…It showed no significant improvement of compressive strength even in comparison to the FA-based geopolymer foam without the addition of GGBFS. As the thermal conductivity was not measured by Su et al, 12 while the porosity was not measured by Zhang et al, 10 the comparison was made with reference to the FA/GGBFS geopolymer foam synthesized by Xu et al 11 With a comparable porosity, the compressive strength was no more than 50% of the reference one. As reviewed, the current database on the highstrength FA-based geopolymer foam is fairly limited.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Investigation on pore properties, thermal conductivity, and compressive behavior of fly ash/slag‐based geopolymer foam

Zhou

Xie

et al. 2023

Int J Applied Ceramic Tech

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Geopolymer foam has emerged as a promising inorganic porous material in the last decade. Despite of the numerous advantages, there are some pending issues to be addressed, on top of that is the low compressive strength. To overcome this, this study synthesizes a high‐strength geopolymer foam by the partial substitution of fly ash (FA) with ground granulated blast furnace slag and carries out an intensive investigation into its microstructure, pore properties, thermal conductivity as well as compressive behavior. The microstructure is firstly analyzed by X‐ray diffraction and Fourier transform infrared spectroscopy techniques. The pore characteristics are also scrutinized, including pore size distribution, total porosity and water absorption. Then, the thermal conductivity is investigated and the applicability of basic effective thermal conductivity models to characterize the relationship with total porosity is evaluated. Afterward, the compressive strength together with the softening coefficient is examined, and the relationship with total porosity is also studied. Finally, comparisons between the proposed geopolymer foam and other FA‐based geopolymer foams in the literature are performed. The results show that the proposed geopolymer foam possesses not only a comparable thermal conductivity but also a far superior compressive strength, which sheds light on the widespread applications in thermal insulation.

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Section: Introductionsupporting

confidence: 65%

Section: Introductionmentioning

confidence: 58%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Investigation on pore properties, thermal conductivity, and compressive behavior of fly ash/slag‐based geopolymer foam

Zhou

Xie

et al. 2023

Int J Applied Ceramic Tech

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“…The fitted wavenumbers of the main peaks ranged from 969 to 1028 cm −1 , which corresponded to the absorption peak of the C-(A)-S-H gel [ 44 ]. According to the literature, the bands at 840 cm −1 –1300 cm −1 in Table 4 are divided into five forms of [SiO 4 ] [ 45 , 46 ]. For the CKD-slag binder pastes, the main existing form of [SiO 4 ] of the C-(A)-S-H gel was entirely Q 2 Si, suggesting that the hydration degree of the product remained unchanged with increased CKD content.…”

Section: Resultsmentioning

confidence: 99%

Mechanical Behavior and Microstructure Evaluation of Quicklime-Activated Cement Kiln Dust-Slag Binder Pastes

Hu,

Dong,

Cui

et al. 2024

Materials

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Cement kiln dust (CKD) is a by-product of cement production, which has the shortcomings of low utilization and high-temperature activation. This study combined CKD and slag as precursors for preparing pastes through quicklime activation under ambient conditions. The effects of quicklime and CKD content on the workability (flowability and setting time), macro-mechanical properties, and micro-structure of the CKD-slag binders were analyzed. The experimental results showed that the rapid precipitation of Ca2+, Si4+, and Al3+ ions from the CKD provided more nucleation sites for the formation of calcium aluminosilicate hydrate (C-(A)-S-H) gel and enhanced the reactivity of the binder system under the influence of the activator (CaO). The specimens had the highest unconfined compressive strength (UCS) (24.6 MPa) after 28 days with 10% quicklime content and 60% CKD content; scanning electron microscopy with energy-dispersive X-ray (SEM-EDX) analysis showed that the Ca/Si ratio of the C-(A)-S-H gel was minimized, leading to a denser microstructure and better binding ability under this mixing proportion. Therefore, this study may provide novel binder materials with a high proportion of CKD under ambient conditions.

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“…The thermal insulation ability of foamed geopolymer is provided mainly by tiny bubbles (generally less than 3 mm) inside the material, which reduce the density at the same time [10]. However, the proportions of interconnected pores and large-aperture pores can be increased [11], impacting the mechanical and thermal insulation properties [5,12,13], causing structural deterioration and reducing the service life of structural components. This considerably restricts the wide application of foamed geopolymer [14].…”

Section: Introductionmentioning

confidence: 99%

Mechanical and Thermal Insulation Properties of rGFRP Fiber-Reinforced Lightweight Fly-Ash-Slag-Based Geopolymer Mortar

Zhang

Qiu

et al. 2023

Sustainability

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As a lightweight cementitious material for thermal insulation, the mechanical performance of foamed geopolymer is always compromised by its density reduction. In this study, recycled-glass-fiber-reinforced plastic (rGFRP) fiber was used to reinforce the fly ash-slag based foamed geopolymer, and vitrified micro bubbles (VMB) were applied to further decrease the thermal conductivity and modify the resistance of the lightweight mortar against drying shrinkage. The results revealed that the density, compressive strength, and thermal conductivity of the foamed geopolymer with/without VMB decreased with the increase in foaming agent content. By adding 2~6% of rGFRP fiber, the compressive strength was increased by 25~165%, and the drying shrinkage was reduced the most, by 55%. After the addition of 10% of VMB, the density, thermal conductivity, and drying shrinkage of foamed geopolymer mortar were further decreased, with the highest reductions of 8%, 26%, and 64%, respectively, due to the reduced pore volume and increase proportion of closed pores. With 6% of rGFRP fiber and 25% of foaming agent, the lightweight geopolymer mortar had the optimum performance, with compressive strength of 1.343 MPa, thermal conductivity of 0.134 W/(m·K), and drying shrinkage of 0.095%. This study developed a sustainable lightweight mortar with multiple types of industrial by-products, which benefit both the development of thermal insulation materials and reuse of solid wastes.

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Mechanical properties and microstructure evaluation of fly ash - Slag geopolymer foaming materials

Cited by 30 publications

References 30 publications

Investigation on pore properties, thermal conductivity, and compressive behavior of fly ash/slag‐based geopolymer foam

Investigation on pore properties, thermal conductivity, and compressive behavior of fly ash/slag‐based geopolymer foam

Mechanical Behavior and Microstructure Evaluation of Quicklime-Activated Cement Kiln Dust-Slag Binder Pastes

Mechanical and Thermal Insulation Properties of rGFRP Fiber-Reinforced Lightweight Fly-Ash-Slag-Based Geopolymer Mortar

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