Experimental characterization of mechanical properties of Bambusa blumeana bamboo poles and determination of design values

Abstract

This research examines the geometric, physical and mechanical properties of graded Bambusa blumeana poles in their natural round form. It presents the first systematic large-sample experimental characterization of all mechanical properties described by ISO 22157:2019. By testing over 1262 samples, it derives the mean and 5th percentile characteristic values of the examined mechanical properties. Findings reveal that a significant percentage of the graded population does not meet the minimum requirements of ISO 22156:2021. However, this does not render the species unviable, as evident by its successful use in thousands of bamboo houses in the Philippines. Instead, it highlights the need to ensure the standard is inclusive of a wider range of bamboo species. Furthermore, the coefficient of variations of the examined mechanical properties are similar to that of conventional building material, i.e. timber, highlighting the quality of the grade. The results also indicate that the ISO 12122–1:2014 non-parametric methods (based on AS/NZS 4063.2) return characteristic values that are consistent with other contemporary standards. In contrast, the parametric approaches for deriving characteristic values seem less suited for the examined dataset. Overall, the derived characteristic values are promising for the engineered design of bamboo structures using round Bambusa blumeana poles.