Eine Plattform für die Wissenschaft: Bauingenieurwesen, Architektur und Urbanistik
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Early mechanical properties and microstructural evolution of slag/metakaolin-based geopolymers exposed to karst water
Abstract As a type of corrosive mixed solution, karst water contains not only chloride and sulfate ions, but also a significant amount of bicarbonate ions. The early mechanical properties and microstructure of a metakaolin-based geopolymer and metakaolin/slag geopolymers (with 20 and 40 wt% slag replacing the metakaolin) immersed in karst water were investigated using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Barrett-Joyner-Halenda (BJH) analysis, and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS). The results showed that a reduction in mechanical strengths associated with variations in the pore size, excess of alkalis (Na2O), decalcification of C-S-H, and calcium carbonate precipitation occurred after immersion in karst water. Furthermore, the geopolymers with the addition of less slag had a greater ability to resist corrosion by karst water. This is related to the formation of calcium carbonate in the calcium-rich geopolymer, along with the excess of alkali (Na+) for activated slag led to dissolve to the karst water.
Early mechanical properties and microstructural evolution of slag/metakaolin-based geopolymers exposed to karst water
Abstract As a type of corrosive mixed solution, karst water contains not only chloride and sulfate ions, but also a significant amount of bicarbonate ions. The early mechanical properties and microstructure of a metakaolin-based geopolymer and metakaolin/slag geopolymers (with 20 and 40 wt% slag replacing the metakaolin) immersed in karst water were investigated using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Barrett-Joyner-Halenda (BJH) analysis, and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDS). The results showed that a reduction in mechanical strengths associated with variations in the pore size, excess of alkalis (Na2O), decalcification of C-S-H, and calcium carbonate precipitation occurred after immersion in karst water. Furthermore, the geopolymers with the addition of less slag had a greater ability to resist corrosion by karst water. This is related to the formation of calcium carbonate in the calcium-rich geopolymer, along with the excess of alkali (Na+) for activated slag led to dissolve to the karst water.
Early mechanical properties and microstructural evolution of slag/metakaolin-based geopolymers exposed to karst water
Xiang, Jichun (Autor:in) / Liu, Leping (Autor:in) / He, Yan (Autor:in) / Zhang, Ning (Autor:in) / Cui, Xuemin (Autor:in)
Cement and Concrete Composites ; 99 ; 140-150
11.03.2019
11 pages
Aufsatz (Zeitschrift)
Elektronische Ressource
Englisch
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