Page 14 - report P Lemoine feb 2013c

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matrix region crystal region
25 160
20
120 Yasrec Y fired
Y asrec
Y fired
Load, mN 15 Load, mN 80
10
40
5
0 0
0 200 400 600 800 1000 0 200 400 600 800 1000
Depth, nm Depth, nm

Figure 10: Nanoindentation averaged Load Displacement curves for the Y as rec and

Y fired samples, for individually positioned indents.

The mechanical property frequency histograms for the crystal regions are shown in
figure 11 and 12, respectively for the E and H values. Comparing to the same

measurements made with random positioning (figure 3 and 4), one can see that here
the E and H values are much higher. One should note, however, that cementous

materials are a complex mixture of a variety of phases; these regions identified in the

optical micrographs as ‘crystals’ may correspond to a variety of different phases with
varying composition and mechanical properties.

The mechanical property frequency histograms for the matrix regions are shown in
figure 13 and 14, respectively for the E and H values. These measurements are more

in line with those obtained in figure 3 and 4 for random positioning, probably because
the matrix constitutes the larger fraction of the cement.

One also observe that, for these indents individually positioned on these two specific

regions, the E and H values for the no Y asrec sample are systematiquely lower.

The variation in measurements on those histograms, for these individually positioned

indents are smaller than for the randomly positioned indents. Moreover, in the crystal
regions, the COV are lower than in the matrix region. This is probably due to the fact

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