Monitoring early hydration of calcium sulfoaluminate clinker

Initial hydration and setting were continuously monitored in calcium sulfoaluminate clinker (KCSA) mixed with water or 2 M NaOH with isothermal conduction calorimetry, ultrasonic pulse velocity (UPV) measurement, the Vicat apparatus, and (in- and ex-situ) X-ray diffraction. P-wave acceleration (ap)...

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Detalles Bibliográficos
Autores: Padilla Encinas, Pilar, Palomo, Ángel, Blanco-Varela, María Teresa, Fernández-Carrasco, Lucía, Fernández-Jiménez, Ana
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2021
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/257647
Acceso en línea:http://hdl.handle.net/10261/257647
Access Level:acceso abierto
Palabra clave:Calcium sulfoaluminate clinker
Calorimetry
Ultrasonic pulse velocity
Setting times
In situ X-ray diffraction
Descripción
Sumario:Initial hydration and setting were continuously monitored in calcium sulfoaluminate clinker (KCSA) mixed with water or 2 M NaOH with isothermal conduction calorimetry, ultrasonic pulse velocity (UPV) measurement, the Vicat apparatus, and (in- and ex-situ) X-ray diffraction. P-wave acceleration (ap) proved highly useful to detect very rapid initial reactions, not generally perceptible with other techniques. Setting in the water-hydrated KCSA pastes was mediated by ettringite formation. Flash setting due to calcium aluminate hydrate precipitation was observed in the 2 M NaOH-hydrated clinker. Ye'elemite reacted most intensely at later times in both pastes, inducing AFt and AH precipitation and the formation of smaller proportions of other calcium aluminate hydrates that densified the matrix.