Structural Properties and suitability of bamboo as a building material.

Abstract

This study investigated the structural properties and suitability of bamboo as an alternative building material with the hope to conserve the declining wood resource. Specifically, three bamboo species, Dendrocalamus asper (Schult. & Schult.f.) Baker, Bambusa vulgaris Schrad.ex J.C.WendI, and Oxytenanthera abyssinica (A.Rich.) Munro at ages 3, 4, and 5 years were examined with the focus to; determine their structural properties at different ages and assess the impact of basic density on the selected strength properties of those bamboo species. Bamboo culms were collected, prepared and tested their Modulus of Rupture (MoR), Modulus of Elasticity (MoE), and Compressive strength parallel to grain, following ISO standards at 12% moisture content using the Tinius olsen universal testing machine. Results showed that D. asper exhibited the highest MoR at both 3 and 4 years, along with the highest MoE across all ages. B. vulgaris displayed the highest MoR at 5 years, while O. abyssinica consistently showed the highest compressive strength at all ages. One way analysis of variance showed significant differences in MoR between D. asper and B. vulgaris (p=0.004), as well as between D. asper and O. abyssinica (p=0.001) at 3 years. Significant differences were also observed at 4 years among all species (p<0.001). The MoE at 5 years showed significant differences among all species (p<0.001). Basic density was found to positively influence MoR and compressive strength parallel to the grain, with moderate correlations for MoR and for compressive strength, while it did not significantly affect MoE. It was concluded that, all species demonstrated increased MoR, MoE, compressive strength and basic density with age, indicating that bamboo strengthens as it matures. Structural properties varied differently among bamboo species. From this study, D. asper can be recommended for structural applications due to its superior MoR and MoE at ages 3 and 4. B. vulgaris is optimal for high-strength applications at 5 years, while O. abyssinica is best suited for applications requiring high compressive strength. Further research is suggested to explore bamboo properties beyond 5 years of age and under varied environmental conditions, as well as to investigate additional strength properties not covered in this study.