NIST Time|NIST Home|About NIST|Contact NIST

HomeAll Years:AuthorKeywordTitle2005-2010:AuthorKeywordTitle

SEM Analysis and Computer Modelling of Hydration of Portland Cement Particles.


pdf icon SEM Analysis and Computer Modelling of Hydration of Portland Cement Particles. (866 K)
Bentz, D. P.; Stutzman, P. E.

ASTM STP 1215;

American Society for Testing and Materials (ASTM). Petrography of Cementitious Materials. Proceedings. ASTM STP 1215. 1995, Am. Soc. for Testing and Matl., Philadelphia, PA, DeHayes, S. M.; Stark, D., Editor(s)(s), 60-73 pp, 1995.

Keywords:

building technology; cement particles; characterization; hydration; image processing; interfacial zone; microstructure; phase analysis; scanning electron microscopy; simulation; x ray images

Abstract:

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.