Wang, S.; Liang, Y.; Mo, D.; Zhang, C.; Xue, J.; Song, X.; Wang, Y. Silica Fume Improves the Mechanical Properties of Alkali-Activated Slag/Fly Ash Pastes Subjected to Elevated Temperatures. Preprints2023, 2023040365. https://doi.org/10.20944/preprints202304.0365.v1
APA Style
Wang, S., Liang, Y., Mo, D., Zhang, C., Xue, J., Song, X., & Wang, Y. (2023). Silica Fume Improves the Mechanical Properties of Alkali-Activated Slag/Fly Ash Pastes Subjected to Elevated Temperatures. Preprints. https://doi.org/10.20944/preprints202304.0365.v1
Chicago/Turabian Style
Wang, S., Xuewen Song and Yachao Wang. 2023 "Silica Fume Improves the Mechanical Properties of Alkali-Activated Slag/Fly Ash Pastes Subjected to Elevated Temperatures" Preprints. https://doi.org/10.20944/preprints202304.0365.v1
Abstract
Recycling of metallurgical solid waste has intriguing increasing attention for fabricating cementitious materials, due to its low-carbon emission, cost-effectiveness, and environmental conservation. Herein, the effects of silica fume (SF) on the microstructure and mechanical properties of alkali-activated slag/FA (fly ash) pastes subjected to elevated temperatures (150, 500, 850, and 1200℃) are investigated, to clarify the fact that whether or not the SF generates positive roles in mechanical properties of slag/FA geopolymers. The results show that the replacement with 10 wt% SF (silica fume) promotes the increasing pore volume with a diameter of 0.2~3 μm at room temperature, leading to an increase in the compressive or flexural strength, “right shifts” of endothermic peak and the initial-final temperature of mass loss, presenting a denser and compact fracture surface. Meanwhile, the mineral phase of gehlenite and labradorite emerges after exposure above 850℃ from the XRD results. Furthermore, the bloating effect of the incorporated SF occurs due to the formation of a liquid phase altogether with the amorphous silicates after exposure to 1200℃, leading to a greater deformation and enhancement of restructuring involved in the [SiO4]4− and [AlO4]5−. It explores an effective recycling approach for fabricating paste binders using metallurgical solid wastes.
Chemistry and Materials Science, Materials Science and Technology
Copyright:
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