Evaluation of the Frictional Properties of Kara Bamboo and their Effects on Bamboo Structural Joints

Housing provision remains a critical challenge in developing countries, and bamboo offers a sustainable solution due to its unique properties. In Iran, local species such as Karabamboo are cultivated, yet effective use in construction requires detailed knowledge of both material properties and joint behavior. This study investigates the wear resistance and friction coefficient of Karabamboo across different culm surfaces, alongside the frictional behavior of various bamboo joint configurations. Results show that the R-θ plane along the R direction exhibited the highest friction coefficient (0.4672) and wear resistance (4.672), while the Z-θ plane along the Z direction on the external culm surface showed the lowest values (0.1927 and 1.927, respectively). Additionally, four joint types—L-shaped, telescopic, sandwich, and mortise (nested)—were fabricated using metal hose clamps and tested under tension. The L-shaped joint demonstrated the highest load-bearing capacity, whereas the telescopic joint had the lowest. The study also found that the effective gripping length of the hose clamp in tensile testing is approximately twice the clamp width. These findings provide crucial insights into designing more efficient bamboo joints and advancing sustainable construction practices with local bamboo species.