On the influence of Dendrocalamus giganteus bamboo microstructure on its mechanical behavior

This paper reports the experimental results of the investigation on the microstructure of Dendrocalamus giganteus bamboo laminae and the influence on its mechanical properties. The laminae were extracted from the central culm sector and from specific wall thickness positions in order to identify the fiber volume fraction, porosity and other matrix constituents, due to the functionally gradient characteristic. Samples were prepared from each set of laminae, both for microanalysis and for mechanical testing, under proposed configurations. The microscale morphology was observed and characterized both qualitatively and quantitatively through transmitted and reflected light microscopy, scanning electron microscopy and X-ray microtomography. An original method was proposed to quantify porosity through a humidity variation test. Tension and compression tests were carried out and their results were discussed with respect to the bamboo microstructure. Additionally the modes of failure were registered and analyzed. Results show that voids constitute an expressive portion of the culm. The mechanical properties are dictated by the fiber volume fraction when the specimens were tested under tensile load and by the density variation when tested under compressive load.