Title:
A Neutron Diffraction-Based Technique for Determining Phase-Resolved Strains in Portland Cement
Author(s):
Sean E. Mikel, Joseph J. Biernacki, and Thomas Gnäupel-Herold
Publication:
Materials Journal
Volume:
106
Issue:
5
Appears on pages(s):
455-460
Keywords:
calcium hydroxide; diffraction; micromechanics; neutron; portland cement; strains.
DOI:
10.14359/51663146
Date:
9/1/2009
Abstract:
The use of X-ray diffraction to directly measure in-place mechanically induced strains in portland cement has recently been demonstrated. These experiments, however, used relatively low energy X-rays, so strain determinations were limited to near-surface effects, for example, ~100 microns (~0.004 in.). Because neutrons are heavy particles, they offer the possibility of deep sample penetration measured in centimeters. The present work evaluates the application of neutron diffraction for measuring bulk in-place strains resolved within mesoscale volumes of approximately 200 mm3 (0.0122 in.3). The findings show that both mechanically induced strains and autogenously generated drying strains can be adequately resolved, offering an essentially new noninvasive method for in-place determination of mechanical responses in portland cement and its composites.