Flexural Properties of Multiple Bamboo Beams with Connection Joints

Bamboo is a natural material widely used in buildings and bridges that has good mechanical properties. However, the longitudinal connection of bamboo culms is a major problem for the bamboo industry. In this study, sleeve-nailed bamboo specimens were produced, which contained three bamboo pieces. Two bamboo pieces with similar diameters were longitudinally joined by inserting a short bamboo culm with a smaller diameter, fixed with nails. The flexural performance of single beams and two-culm beams were studied. The load-displacement curves and fracture behavior of the specimens were investigated. The results show that the flexural bearing capacity of the single connected bamboo specimen was relatively smaller than that of an unconnected one, while the flexural bearing capacity of the two-culm beam was improved significantly. It can be seen that the lateral connection of bamboo specimens can improve the bearing capacity of the combined bamboo culms. This study provides a basis for promoting the application of sleeve-type nailed connections for bamboo.