SEM/X-Ray Imaging of Cement-Based Materials.
SEM/X-Ray Imaging of Cement-Based Materials.
(888 K)
Bentz, D. P.; Stutzman, P. E.; Haecker, C. J.; Remond,
S.
Microscopy Applied to Building Materials, 7th
Euroseminar. Proceedings. June 29-July 2, 1999, Delft,
The Netherlands, Delft University of Technology, Delft,
The Netherlands, Pietersen, H. S.; Larbi, J. A.;
Janssen, H. H. A., Editor(s)(s), 457-466 pp, 1999.
Keywords:
cements; x ray imaging; correlation; image analysis;
microstructure; scanning electron microscopy;
segmentation; fly ash
Abstract:
Scanning electron microscopy and X-ray imaging
techniques have been developed for imaging the complex
microstructure of cement-based materials such as cement
powder and fly ash. By combining the information
available in the backscattered electron and relevant
X-ray images, an accurate segmentation of the image into
individual cement clinker phases or other components can
be accomplished. This paper reviews the image
acquisition and processing techniques used in performing
this analysis, as well as the statistics that can be
used to characterize the final 2-D microstructures, such
as area fractions, surface fractions, and two-point
correlation functions. In addition, two applications
are presented: 1) the imaging of a series of fly ashes
from different sources, and 2) the analysis of cement
microstructure as a function of grinding fineness. The
resultant images provide the quantitative
characterization needed for input into three-dimensional
computer models of cement hydration and microstructural
development.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899