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In Situ 27 Al NMR Studies of Cement Hydration: The Effect of Lithium‐Containing Setting Accelerators
Author(s) -
Luong Tim,
Mayer Hermann,
Eckert Hellmut,
Novinson Thomas I.
Publication year - 1989
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/j.1151-2916.1989.tb06045.x
Subject(s) - magic angle spinning , induction period , lithium (medication) , in situ , materials science , nuclear magnetic resonance spectroscopy , phase (matter) , isotopes of lithium , aluminium , chemistry , cement , analytical chemistry (journal) , ion , composite material , stereochemistry , catalysis , organic chemistry , ion exchange , medicine , endocrinology
Hydration of calcium aluminate cements is known to cause phase transformations during which the coordination number of aluminum by oxygen changes from 4 to 6. Systematic 27 Al magic angle spinning and wide‐line nuclear magnetic resonance (NMR) experiments at 78.3 MHz with detailed attention to the quantitative aspects of quadrupolar NMR spectroscopy show that the fraction of Al(6) is a monotonic function of the water/solid (w/s) ratio and does not depend on the type and concentration of setting accelerators. In situ 27 Al wide‐line NMR measurements during the hydration process can provide good estimates of the induction period and the rate of the phase conversion. Using this approach, lithium carbonate at a concentration of 0.5 wt% of the mixing solution has been shown to eliminate the induction period but to leave the rate of the phase conversion essentially unchanged.