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Performances and microstructure of one-part fly ash geopolymer activated by calcium carbide slag and sodium metasilicate powder
https://orcid.org/0000-0002-5332-7862
https://orcid.org/0000-0002-7938-8057
https://orcid.org/0000-0002-1796-3968
Highlights The 1d compressive strength of the sample can reach 24.8 MPa. The effect of compound activator is better than that of single activator. Preparation of fly ash geopolymer with Na2SiO3/carbide slag synergistic wet-grinding. Compound activators are expected to reduce the use of NaOH activators. It provides an effective way for the utilization of low calcium fly ash.
Abstract As the raw material of geopolymer, F-class fly ash (FFA) often needs strong alkali such as NaOH to stimulate due to its low reactivity. In this study, FFA was refined and activated by a wet grinding process, and the activation effect of calcium carbide slag (19 %) and sodium silicate (1 %, 3 % and 5 %) was evaluated when used alone or in combination. The results show that the compound activator significantly improves the hydration products and mechanical properties of the wet-grinding FFA geopolymer. Compared with the single activation system, the 28-day hydration product content of the compound activation (co-activation) system increased by 67 %, and the 1-day compressive strength reached 24.8 MPa (at least an increase of 118 %). In addition, the co-activation system significantly improved the pore structure of the geopolymer and increased the chain length and Al/Si ratio of the C-S-H gel. The results of this study showed that co-activation and mechanical activation can significantly enhance the FFA geopolymer's mechanical characteristics and microstructure, greatly encourage the ingestion of industrial solid waste, lower the application costs of high pH activators, and efficiently provide a method for the utilization of FFA.
Performances and microstructure of one-part fly ash geopolymer activated by calcium carbide slag and sodium metasilicate powder
https://orcid.org/0000-0002-5332-7862
https://orcid.org/0000-0002-7938-8057
https://orcid.org/0000-0002-1796-3968
Highlights The 1d compressive strength of the sample can reach 24.8 MPa. The effect of compound activator is better than that of single activator. Preparation of fly ash geopolymer with Na2SiO3/carbide slag synergistic wet-grinding. Compound activators are expected to reduce the use of NaOH activators. It provides an effective way for the utilization of low calcium fly ash.
Abstract As the raw material of geopolymer, F-class fly ash (FFA) often needs strong alkali such as NaOH to stimulate due to its low reactivity. In this study, FFA was refined and activated by a wet grinding process, and the activation effect of calcium carbide slag (19 %) and sodium silicate (1 %, 3 % and 5 %) was evaluated when used alone or in combination. The results show that the compound activator significantly improves the hydration products and mechanical properties of the wet-grinding FFA geopolymer. Compared with the single activation system, the 28-day hydration product content of the compound activation (co-activation) system increased by 67 %, and the 1-day compressive strength reached 24.8 MPa (at least an increase of 118 %). In addition, the co-activation system significantly improved the pore structure of the geopolymer and increased the chain length and Al/Si ratio of the C-S-H gel. The results of this study showed that co-activation and mechanical activation can significantly enhance the FFA geopolymer's mechanical characteristics and microstructure, greatly encourage the ingestion of industrial solid waste, lower the application costs of high pH activators, and efficiently provide a method for the utilization of FFA.
Performances and microstructure of one-part fly ash geopolymer activated by calcium carbide slag and sodium metasilicate powder
https://orcid.org/0000-0002-5332-7862
https://orcid.org/0000-0002-7938-8057
https://orcid.org/0000-0002-1796-3968
Highlights The 1d compressive strength of the sample can reach 24.8 MPa. The effect of compound activator is better than that of single activator. Preparation of fly ash geopolymer with Na2SiO3/carbide slag synergistic wet-grinding. Compound activators are expected to reduce the use of NaOH activators. It provides an effective way for the utilization of low calcium fly ash.
Abstract As the raw material of geopolymer, F-class fly ash (FFA) often needs strong alkali such as NaOH to stimulate due to its low reactivity. In this study, FFA was refined and activated by a wet grinding process, and the activation effect of calcium carbide slag (19 %) and sodium silicate (1 %, 3 % and 5 %) was evaluated when used alone or in combination. The results show that the compound activator significantly improves the hydration products and mechanical properties of the wet-grinding FFA geopolymer. Compared with the single activation system, the 28-day hydration product content of the compound activation (co-activation) system increased by 67 %, and the 1-day compressive strength reached 24.8 MPa (at least an increase of 118 %). In addition, the co-activation system significantly improved the pore structure of the geopolymer and increased the chain length and Al/Si ratio of the C-S-H gel. The results of this study showed that co-activation and mechanical activation can significantly enhance the FFA geopolymer's mechanical characteristics and microstructure, greatly encourage the ingestion of industrial solid waste, lower the application costs of high pH activators, and efficiently provide a method for the utilization of FFA.
Performances and microstructure of one-part fly ash geopolymer activated by calcium carbide slag and sodium metasilicate powder
Yang, Jin (author) / Bai, Hang (author) / He, Xingyang (author) / Zeng, Jingyi (author) / Su, Ying (author) / Wang, Xiaodong (author) / Zhao, Huang (author) / Mao, Chunguang (author)
2023-01-02
Article (Journal)
Electronic Resource
English
Strength properties of slag/fly ash blends activated with sodium metasilicate
| DOAJ | 2017
| DOAJ | 2018