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Effect of synthesis procedure on carbonation of calcium‐silicate‐hydrate
Author(s) -
Hunnicutt William,
Struble Leslie,
Mondal Paramita
Publication year - 2017
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/jace.14899
Subject(s) - carbonation , calcium silicate hydrate , thermogravimetric analysis , hydrate , chemistry , alkali metal , calcium hydroxide , sodium hydroxide , inorganic chemistry , silicate , decomposition , calcium silicate , fumed silica , chemical engineering , mineralogy , nuclear chemistry , materials science , cement , organic chemistry , metallurgy , engineering
Carbonation of synthesized calcium‐silicate‐hydrate (C–S–H) is difficult to avoid and can have significant impact on the molecular structure. Considerable carbonation was observed in C–S–H synthesized from the double decomposition of sodium silicate and calcium nitrate solutions but not in C–S–H synthesized from the direct reaction of fumed silica and calcium hydroxide solution. In order to isolate the cause of the greater carbonation in C–S–H synthesized by double decomposition, carbonation was induced in phase‐pure C–S–H by reaction with four different water‐based solutions containing dissolved CO 2 with varying pH and alkali content. Powder X‐ray diffraction, thermogravimetric analysis, and 29 Si nuclear magnetic resonance were used to probe the carbonation and the resulting changes in molecular structure. The pH of the solution was seen to strongly influence the degree of carbonation, while the alkali content had much less effect.