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35mm and 20mm for middle part II in average (Figure.1, 3). Over all dimensional fluctuations
were about 1‐2%.
Figure 3. Sample set (parts I, II and III) with inserted heat source and thermocouple. The silicon paste
with Al2O3 powder filler (Midland Silicon Ltd.) was used to improve thermal contact between all parts.
The weight of each part of specimen set was measured before the measurement. After than the
average volume densities of samples were recalculated and are plotted in figure 4 in
dependency on moisture content. This plot gives the view on sate of conditioning. While the
sample batches P1 and P2 show nearly linear dependency, the sample batches P5 and P6 show
larger data scattering. The first reason of larger data scattering for lower density material is that
the fluctuations of pore distribution should be larger than in a case of material having higher
densities. This is the reason why the sample of 0 Wt% of moisture have the volume density
greater than those one with moisture content 3 and 6 Wt%. Similar behaviour was observed for
P6 specimens with 10 and 15 Wt% of moisture. The next reason of data scattering is caused
most probably by the fact that moisture conditioning was broken. The measurements were
performed in hot days from August till September 2008. The samples were kept just at room
temperatures in plastic bags sealed with plastic zip and were probably dried in not defined
way. Unfortunately, the moisture content was not able to recalculate before the measurement
due to lost of weight data measured before the conditioning of materials in dry state. So in this
case another view on data plot based on dependency on densities instead of moisture content
give more reliable information on this problem. This fact is illustrated on figure 4, 5 and 6.
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