Preparation of Metakaolin Based Geopolymer and Its Three- dimensional Pore Structural Characterization
来源期刊：Journal Of Wuhan University Of Technology Materials Science Edition2015年第3期
论文作者：张云升 ZHANG Wenhua SUN Wei LI Zongjin LIU Zhiyong
文章页码：550 - 555
摘 要：Three types of pure geopolymer pastes（poly-sialate PS, poly- sialate-siloxo PSS, and polysialate-siloxo PSDS） were fi rst prepared by alkali（Na OH and KOH） activated metakaolin. Then a void space network was employed to simulate the 3-D pore-throat distribution across the unit cell of the various hardened geopolymer pastes with reference to their experimental mercury intrusion curves. Based on the simulated 3-D pore-throat structure models, a wide range of pore-level properties such as porosity, connectivity, permeability and tortuosity of various geopolymer pastes were calculated. The 3-D structural model and calculated parameters showed that most of the pores in Na-PS geopolymer paste was very small size pores ranging from 0 to 100 nm. A few very large pores were spread amongst the small pores, resulting in a very high penetration pressure, permeability resistance. Unlike Na-PS geopolymer paste, pore size with medium size of Na-PSS, K-PS and K-PSS geopolymer pastes distributed uniformly across the unit cell, and the size changes of adjacent pores in the 3 geopolymer pastes were little, producing higher penetration pressure, lower permeability, smaller connectivity and larger tortuosity. In contrast, pores in Na-PSDS and K-PSDS geopolymer pastes were relatively large and distributed concentratively, which caused samples to be easily penetrated by mercury, methane and nitrogen etc under relatively low pressures.
张云升1，ZHANG Wenhua1，SUN Wei1，LI Zongjin2，LIU Zhiyong1
1. Jiangsu Key Laboratory for Construction Materials, Southeast University2. Department of Civil and Engineering, Hong Kong University of Science and Technology
摘 要：Three types of pure geopolymer pastes（poly-sialate PS, poly- sialate-siloxo PSS, and polysialate-siloxo PSDS） were fi rst prepared by alkali（Na OH and KOH） activated metakaolin. Then a void space network was employed to simulate the 3-D pore-throat distribution across the unit cell of the various hardened geopolymer pastes with reference to their experimental mercury intrusion curves. Based on the simulated 3-D pore-throat structure models, a wide range of pore-level properties such as porosity, connectivity, permeability and tortuosity of various geopolymer pastes were calculated. The 3-D structural model and calculated parameters showed that most of the pores in Na-PS geopolymer paste was very small size pores ranging from 0 to 100 nm. A few very large pores were spread amongst the small pores, resulting in a very high penetration pressure, permeability resistance. Unlike Na-PS geopolymer paste, pore size with medium size of Na-PSS, K-PS and K-PSS geopolymer pastes distributed uniformly across the unit cell, and the size changes of adjacent pores in the 3 geopolymer pastes were little, producing higher penetration pressure, lower permeability, smaller connectivity and larger tortuosity. In contrast, pores in Na-PSDS and K-PSDS geopolymer pastes were relatively large and distributed concentratively, which caused samples to be easily penetrated by mercury, methane and nitrogen etc under relatively low pressures.
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