Loading...
Quantitative Backscattered Electron Analysis Techniques for Cement-Based Materials
Zhao, Hong Darwin, David
Zhao, Hong
Darwin, David
Citations
Altmetric:
Abstract
Backscattered electron imaging and x-ray microanalysis are used to identify phases within polished epoxy impregnated cement paste sections. A silicon-magnesium standard is applied and an objective procedure is developed for the calibration of the scanning electron microscope and the image analysis system, so that the L;tensity of individual phases in cement paste appears within reproducible ranges when using backscattered electron imaging, The techniques allow for consistency in quantitative analysis of cement microstructure. Image analysis of cement phases is carried out and a statistical basis is established for the number of frames that must be analyzed to obtain a satisfactory level of confidence in the data. Backscattered electron imaging of polished surfaces of cement paste can be used to distinguish the phases within unhydrated cement particles and the phases of cement I hydration products. The existence of calcium hydroxide within inner product is confirmed, For image analysis, the number of frames required for a selected level of confidence decreases as the magnification decreases, while the total area required increases as the magnification decreases. To achieve a desired level of confidence in image analysis for the phases of hydrated cement paste, unhydrated cement particles require the greatest number of frames, while inner product and calcium silicate hydrate require the least number of frames.
Description
Date
1990-06
Journal Title
Journal ISSN
Volume Title
Publisher
University of Kansas Center for Research, Inc.
Research Projects
Organizational Units
Journal Issue
Keywords
Backscattered electron imaging, Backscattering coefficient, Calibration, Cement paste, Cracking, Epoxy impregnation, Gray levels, Hydration, Image analysis, Intensities, Microstructures, Phases, Polishing, Quantitative analysis, Standard, Voids, X-ray dot mapping, X-ray microanalysis
Citation
Zhao, H., and Darwin, D., "Quantitative Backscattered Electron Analysis Techniques for Cement-Based Materials," SM Report No. 24 Research Grant AFOSR-89-0296, The Air Force Office of Scientific Research, June 1990, 57 pp.