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Hydrothermal Solidification of Kaolinite–Quartz–Lime Mixtures
Author(s) -
Maenami Hiroki,
Watanabe Osamu,
Ishida Hideki,
Mitsuda Takeshi
Publication year - 2000
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.2000.tb01458.x
Subject(s) - tobermorite , kaolinite , quartz , hydrothermal circulation , materials science , flexural strength , lime , mineralogy , calcium silicate hydrate , calcium silicate , silicate , chemical engineering , metallurgy , chemistry , composite material , cement , engineering
The strength development of hydrothermally solidified kaolinite–quartz–lime systems with kaolinite as the aluminum source was studied. The starting materials were mixed so that the Ca/(Si + Al) atomic ratio was in the range 0.23 to 0.25, and the Al/(Si + Al) ratio was between 0 to 0.50. Specimens were formed by uniaxial pressing and hydrothermal treatment under saturated steam pressure at 200°C for 2 to 20 h. For quartz‐rich systems with Al/(Si + Al) = 0 and 0.05, strength development by the formation of calcium silicate hydrates, such as C–S–H and tobermorite (Ca 5 (Si 6 O 18 H 2 )·(4H 2 O), was observed. On the other hand, in the case of kaolinite‐rich systems with Al/(Si + Al) = 0.24 to 0.50, strength development by the formation of hydrogarnet (Ca 3 Al 2 (SiO 4 )(OH) 8 ) was recognized, resulting in flexural strengths between 15 to 20 MPa. It is proposed that strength development is related to the formation of mesopores (∼0.04 μm) that accompanied formation of the hydrogarnet.