Print Email Facebook Twitter Study of carbonation rate of synthetic C-S-H by XRD, NMR and FTIR Title Study of carbonation rate of synthetic C-S-H by XRD, NMR and FTIR Author Wu, B. (TU Delft Materials and Environment) Ye, G. (TU Delft Materials and Environment; Universiteit Gent) Date 2019 Abstract Supplementary cementitious materials (SCMs) like fly ash (FA) and blast furnace slag (BFS) are broadly used in concrete to replace part of the Ordinary Portland Cement (OPC) because of both economic and environmental issues. In concrete blended with SCMs, C-S-H with different C/S ratios, formed from the hydration and pozzolanic reactions of blended cement, is the major calcium-bearing phases which reacts with CO2 during carbonation. Therefore, it is important to study the carbonation rate of different C-S-H phases. In this paper, the C-S-H phases (C/S ratio: 0.66 to 2.0) were synthesized and used for accelerated carbonation testing. Synthetic C-S-H phases with different C/S ratios were identified by X-ray diffraction and 29Si nuclear magnetic resonance (NMR). Carbonation rate and products of different C-S-H phases are also determined. The results show that C-S-H (I) phases with different target C/S ratio (lower than 1.40) were synthesized in the mix solution of lime and fume silica. The portlandite appears in the products when the designed C/S ratio is higher than 1.40 under this synthetic condition. C-S-H with lower C/S ratio is decomposed faster than that with a higher C/S ratio. After exposition to the accelerated carbonation condition for three days, in this research, the C-S-H phases with different C/S ratio were all fully decomposed to CaCO3 and silica gel. Subject C-S-HC/S ratioCarbonation rateStructure To reference this document use: http://resolver.tudelft.nl/uuid:efd7186f-3e93-4765-8734-5a783298d461 ISSN 0046-7316 Source Heron, 64 (1-2), 21-38 Part of collection Institutional Repository Document type journal article Rights © 2019 B. Wu, G. Ye Files PDF 2.pdf 844.46 KB Close viewer /islandora/object/uuid:efd7186f-3e93-4765-8734-5a783298d461/datastream/OBJ/view