A thermodynamic and experimental study of the conditions of thaumasite formation
作者： Thomas Schmidt , Barbara Lothenbach , Michael Romer , Karen Scrivener , Daniel Rentsch
DOI: 10.1016/J.CEMCONRES.2007.11.003
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摘要: The formation of thaumasite was investigated with the progressive equilibrium approach (PEA). This experimentally simulates conditions various levels sulfate addition in hardened cement pastes. influence limestone, time, C(3)A content, temperature and leaching on investigated. results show that is favoured at lower temperatures (8 degrees C) independently type clinker (high or low content) used. Thaumasite found to form only systems where limestone present sufficient had been added. precipitated systerns Al has already consumed ettringite inolar SO3/Al2O3 ratio exceeded 3. In leached samples (reduction portlandite alkalis) slightly less formed whereas gypsum are under these conditions. PEA, used investigate chemical aspects attack be a good tool for simulating external attack. Generally, detected were it modelled stable significant amounts. However, this study not reached after 9 months. (C) 2007 Elsevier Ltd. All rights reserved.
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