A Magnetic Resonance Imaging Technique to Determine Lithium Distribution in Mortar
J. J. Young, B. J. Balcom, T. W. Bremner, M. D. A. Thomas,
and K. Deka
Appears on pages(s):
alkali-silica reaction; lithium; magnetic resonance imaging; nondestructive testing
Magnetic Resonance Imaging (MRI) is a nondestructive technique that can be used to spatially resolve distributions of certain nuclei. Lithium is a relatively sensitive nucleus for MRI. Therefore, it is possible to directly measure the distribution of lithium in cement based materials. Lithium salts are used in concrete to suppress alkali-silica reaction. The MRI relaxation parameters associated with lithium in cement-based materials are relatively short by traditional MRI standards. Due to the short relaxation parameters, special MRI measurement techniques and hardware considerations had to be developed in order to quantify lithium distributions in cement based materials. MRI has the potential to play an important role in concrete technology. While this method has been developed for laboratory studies, measurements could be made on cores extracted from existing concrete structures.