The pattern and extent of variation of microfibril angle (MFA) in normal and compression tracheids of softwood were investigated by using confocal laser scanning microscopy technique. All measurements support the idea that the orientation of microfibrils in single wood tracheids is not uniform. MFA of the radial wall of earlywood tracheids was highly non-uniform and had an approximately circular form of arrangement around the bordered pits (inside the border). Between the bordered pits the measured MFAs were less than the other parts of the tracheid. In the latewood tracheids MFA was less variable. The average orientation of simple pits in the crossfield region was consistent with the mean MFA of the tracheids; however some of the measurements showed a highly variable arrangement in the areas between the simple pits. In many cases the local measured MFAs of compression wood tracheids agreed with the orientation of natural helical cavities of compression wood. Comparing the measured results in different growth rings showed that MFAs in juvenile wood are generally larger than in perfect wood.

A methodology for assessment of long term properties of unbound recycled granular materials for use in base courses of road pavements is described. A special polymer technique is described for observing the fragmentation and anisotropy of granular materials after compaction. This method has two main advantages: simple and speed of use. The method also uses a modified Proctor Test with polymer impregnation being applied under vacuum. The compaction and analysis of a limestone aggregate sample is briefly described. The vertical and horizontal cross-sections of the sample were observed using digital imaging and processing techniques, and observations of cut segments observed with a microscope. Important information about aggregate shape, size, orientation and distribution throughout the volume and within the compaction layers is gathered through visual observation and morphological analysis. The method is also applicable to other observational issues, such as rheological state changes of inter-granular contacts due to changes in cement past thus, for example, enabling the fundamental behaviour patterns of alkali-aggregate reaction to be studied in detail.

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