2024-03-28T16:28:22Zhttp://digital.csic.es/dspace-oai/requestoai:digital.csic.es:10261/1225792021-07-22T10:02:21Zcom_10261_23com_10261_3com_10261_31col_10261_402col_10261_410
Assessment of restoration of alkaline reserve during realkalisation of carbonated cementitious materials
Castellote, Marta
Llorente, Irene
Campo, Javier
Resumen del trabajo presentado a la "VII Reunión de la Sociedad Española de Técnicas Neutrónicas" celebrada en Pamplona del22 al 25 de junio de 2014.
Neutron diffraction has been successfully applied to solve different problems related to construction materials, mainly profiting the possibility of studying the bulk of materials using quite big specimens, the difference in scattering between light and deuterated water and in situ monitoring the experiments, making it possible the establishment of the kinetics of the processes. In this work, in-situ monitoring of the electroosmotic flux, during realkalisation, by neutron diffraction is reported. This was achieved by designing the experimental set-up in a way to take profit of the incoherent scattering of the H of the water. Two series of cement pastes, cast with CEM I and CEM I substituted in a 35% by fly ash, previously carbonated at 100% CO2, were submitted to realkalisation treatments followed on line by simultaneous acquisition of neutron diffraction data. The analysis of soluble carbonates in the specimen, after the experiments, has confirmed the electroosmotic flux as the driving force of the realkalisation treatment. Additionally, it has been confirmed that as a consequence of the treatment, there is precipitation of portlandite on the rebar and on the zone close to the negative electrode as far as the pH is high enough. The provision of Ca2+ ions comes mainly from the dissolution of calcite. So, it has been assessed the possibility to restore the alkaline reserve by passing enough amount of charge during the realkalisation treatment.
2015-09-24T10:25:04Z
2015-09-24T10:25:04Z
2014
2015-09-24T10:25:04Z
comunicación de congreso
SETN 2014
http://hdl.handle.net/10261/122579
eng
Sí
closedAccess