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Microstructure of Mature Alite Pastes
Author(s) -
MARCHESE BERNARDO
Publication year - 1978
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.1151-2916.1978.tb09326.x
Subject(s) - alite , microstructure , aragonite , materials science , phase (matter) , calcite , portland cement , mineralogy , silicate , cement , chemical engineering , composite material , chemistry , clinker (cement) , organic chemistry , engineering
Tricalcium silicate and Fe‐bearing alite pastes hydrated 4 years and portland cement paste hydrated 33 days were studied by SEM, TG, and XRD. SEM studies of the effect of water, NaCl, and MgSO 4 solutions on the microstructure of alite are reported. The characteristics of the attack were clarified by examining both sides of the fracture plane. The Ca(OH) 2 phase present in the fresh fracture surface is very unstable toward water, NaCl, and MgSO 4 solutions. When exposed to MgSO 4 solution the Ca(OH) 2 reacts, producing Mg(OH) 2 and CaSO 4 ·2H 2 O. The C‐S‐H gel phase is more resistant to the various reactants. The presence of calcite, aragonite, and Ca(OH) 2 and their proportion in the surface layer depend on the characteristics of the environment.