RESULTS AND DISCUSSION
Bulk Samples
Despite the homogenization of the particles, Figures 1 and 2 show that the three
elaborated thin sections present different particle dominance and type of pores, and poorly
sorted, even when the ratio was the same (60:40 Cf-T, Ve-T). Figure 1b shows a greater
number of T particles (35%) than Figure 1a and c (10-15%), which present more Cf (up to
85%); whereas, Figure 1b is poorly sorted, compared to the other thin sections in the same
Figure 1, which were classified as moderately sorted. It is noteworthy that Figure 1c has
more closed packing voids than the other thin sections from the same figure because
interconnected vughs were generated as the Cf particles grouped together. Bullock et al.
(1985) indicated that the mixture of organic and inorganic materials generates complex
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packing voids, given the presence of storage and percolation pores. The fact that the ratio
between particles is different, even within the same mixture, can cause dominance in a
container of percolation pores, as in the case of T, while in other containers there might
be a dominance of storage pores, as in the case of Cf. These macropores have a
percolation function, which further complicates reproducibility of the physical data in
bulk samples, since some containers may have greater drainage than others. Coconut fiber
has been reported to have variations in its physical properties, according to its origin
(Vargas et al., 2008a), while T has variations in the percentage of porosity even within
mines in the same locality (Vargas et al., 2008b); thus it is always necessary to evaluate
the properties of each material.