Backscattered electron image analysis of cement paste specimens: Specimen preparation and analytical methods

1991 ◽  
Vol 21 (2-3) ◽  
pp. 388-390 ◽  
Author(s):  
Knut O. Kjellsen ◽  
Rachel J. Detwiler ◽  
Odd E. Gjørv
Keyword(s):  
Image Analysis ◽  
Cement Paste ◽  
Analytical Methods ◽  
Specimen Preparation ◽  
Electron Image ◽  
Backscattered Electron

Microstructural Gradients in Cement Paste Around Aggregate Particles

1987 ◽  
Vol 114 ◽  
Author(s):  
Karen L. Scrivener ◽  
Ellis M. Gartner
Keyword(s):  
Image Analysis ◽  
Cement Paste ◽  
Interfacial Zone ◽  
Microstructural Investigation ◽  
Analysis Technique ◽  
Single Piece ◽  
Quantitative Image ◽  
Backscattered Electron ◽  
Condensed Silica Fume ◽  
Aggregate Particles

ABSTRACTThe effectiveness of condensed silica fume as a strength enhancing additive in concrete has been attributed to its ability to modify the interfacial zone between paste and aggregate. This paper describes a microstructural investigation of this interface using backscattered electron (bse) imaging combined with quantitative image analysis.Composite specimens were made in which a single piece of aggregate was embedded in cement paste. Granite, dolomite and garnet aggregates were used. After curing, the specimens were sectioned perpendicular to the surface of the aggregate particles and polished. The variation in porosity, amount of anhydrous material and calcium hydroxide (CH), with distance from the aggregate surface was measured. It was found that the porosity increases in the paste close to the interface, while the content of anhydrous grains decreases. No significant increase in CH content was found near the interface.The results confirm the applicability of the bse - image analysis technique, but indicate that the interfaces in specimens prepared in this manner may not be representative of aggregate paste interfaces in concrete.

scholarly journals APPLICATION OF IMAGE ANALYSIS TO ASSESSING CRITICAL PORE SIZE FOR PERMEABILITY PREDICTION OF CEMENT PASTE

2011 ◽  
Vol 22 (2) ◽  
pp. 97 ◽  
Author(s):  
Jing Hu ◽  
Piet Stroeven
Keyword(s):  
Image Analysis ◽  
Pore Size ◽  
Cement Paste ◽  
Image Resolution ◽  
Effective Media ◽  
Theory Comparison ◽  
Backscattered Electron ◽  
Image Analysis Techniques ◽  
Insight Into ◽  
Good Agreement

This paper explores image analysis techniques that provide insight into the nature of pore structure as observed in backscattered electron images of polished sections. On the basis of mathematical morphology, the pore size distribution is characterised and the critical pore size is determined for cement paste at different hydration time. The influence of image resolution is investigated. The permeability of cement paste can be predicted according to General Effective Media (GEM) theory. Comparison between permeability estimation and experiment results reveals good agreement.

The Use Of Backscattered Electron Microscopy And Image Analysis To Study The Porosity Of Cement Paste

1988 ◽  
Vol 137 ◽  
Author(s):  
Karen L. Scrivener
Keyword(s):  
Electron Microscopy ◽  
Image Analysis ◽  
Cement Paste ◽  
Serial Section ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Image Analyser ◽  
Backscattered Electron ◽  
Solid Phases ◽  
Serial Section Reconstruction

AbstractIn backscattered electron images of polished sections of cement paste pores can be identified down to a size of about 0.05 microns. Moreover, the contrast between pores and the solid phases is sufficient to allow the pores to be distinguished and quantified by an image analyser. There is a good correlation between measures of porosity obtained by this technique and those obtained by methanol absorbtion methods despite the lower limit to resolution.The bse method can also be used to study the distribution of the porosity in space. However, as only two dimensional sections can be examined, there are difficulties in determining the connectivity by this method. The possibility of using serial section reconstruction is examined and discussed.Despite the difficulty in relating two dimensional characterisation to three dimensional properties, several techniques have been used with some success for sandstones. Results from these techniques for cement paste are presented and discussed.

Analysis of Phases in Cement Paste using Backscattered Electron Images, Methanol Adsorption and Thermogravimetric Analysis

1986 ◽  
Vol 85 ◽  
Author(s):  
Karen L. Scrivener ◽  
H. H. Patel ◽  
P. L. Pratt ◽  
L. J. Parrott
Keyword(s):  
Image Analysis ◽  
Thermogravimetric Analysis ◽  
Calcium Hydroxide ◽  
Cement Paste ◽  
Image Analyzer ◽  
Hydration Products ◽  
Grey Level ◽  
Methanol Adsorption ◽  
Backscattered Electron ◽  
Material Porosity

ABSTRACTIn backscattered electron (bse) images of polished cement sections, anhydrous material, calcium hydroxide, other hydration products (mainly C-S-H) and porosity can be distinguished on the basis of their grey level in the image. Using an image analyzer connected directly to the SEM, it is possible to resolve these four components and so measure their relative proportions and distributions. The effects of magnification and the number of fields measured on the accuracy of bse image analysis are examined. The volume fractions of anhydrous material, porosity and calcium hydroxide derived from bse image analysis are compared with those obtained by other techniques and good correlation was found for the measurement of anhydrous material and porosity.

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