Bamboo has been identified as a possible substitute for the declining supply of timber in Malaysia. The unique characteristics of bamboo, being fast growing and abundantly available, qualify bamboo as a material of the future.
The main objective of this study was to determine the within culm variation of physical, anatomical and mechanical properties (at different moisture conditions) of G. scortechinii splits and strips for structural application. The relationships between these traits were also studied.
The physical and anatomical properties of splits strips from different height position and section showed significant variation. Studies on the anatomical characteristics at the transverse section have provided important information regarding mechanical properties at different moisture conditions and also concerning failure characteristics.
Bamboo is known for its hygroscopic character. An in-depth study of the dimensional changes of bamboo splits and strips showed significant differences between the radial and tangential directions. Physical changes were observed in the samples after the second cycle of moisture changes, including irregular shrinkage, distortion and cracks. Exposure of samples to different relative humidities on desorption and adsorption provides new information on the equilibrium moisture contents attainable by G. scortechinii. The Hailwood and Horrobin model was used to help explain the sigmoidal shape observed in
the study. The fibre saturation point of G. scortechinii obtained by extrapolation was 23.6 percent.
A study of the microfibril angle in the secondary wall of bamboo fibres confirmed findings of earlier investigations (from other countries using different species) although with some deviations. The mean microfibril angle determined at the broad and narrow lamellae were 6° and 86.1 ° respectively.
The mechanical properties of splits and strips from different height positions (internode and with node present) from mature 4-year old bamboo G. scortechinii were determined at different moisture conditions. Bamboo shows a similar behaviour as wood, with most mechanical properties increasing with decrease in moisture. The mechanical properties of
bamboo samples tested in the green condition is about 57 percent lower than when tested below the fibre saturation point. The mechanical properties are generally higher for the internode than the node but for the strips-middle, the mechanical properties were higher in samples with node present. This finding thus eliminates initial assumptions that due to their
low strength and stiffness the presence of nodes would be a hindrance to utilisation. A statistical model was also developed to explain the effect of sample variation in the properties determined.