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Dale P. Bentz1 and Paul E. Stutzman1
Characterization of cement particles is complicated due to their wide size range, complex shapes, and multi-phase nature. Accurate characterization should allow for better prediction of cement performance and more realistic modelling of cement microstructural development. This paper presents a technique, based on scanning electron microscopy and digital image processing, for obtaining two-dimensional digital images of actual portland cement particles in which all major phases are identified. By combining backscattered electron and X-ray images, an image segmented into the major cement phases may be created. These images can be analyzed to determine any number of quantitative measures such as phase fractions or phase perimeters. The technique has also been successfully utilized in obtaining realistic starting images for input into a two-dimensional cement microstructure model which simulates the hydration process.
KEYWORDS: building technology, cement particles, characterization, hydration, image processing, interfacial zone, microstructure, phase analysis, scanning electron microscopy, simulation, X-ray images.
1 Chemical engineer and physical scientist respectively, Building Materials Division, Building and Fire Research Laboratory, National Institute of Standards and Technology, U.S. Department of Commerce, Gaithersburg, MD 20899