Cyclic behaviour of exterior bamboo scrimber beam-to-column connections

With the advance in manufacturing technology, hot-pressed bamboo scrimber has been produced and widely utilised in construction practices in China. However, no design methods are available for bamboo scrimber members at present. Even though design equations for glulam structures are often used for bamboo scrimber members and connections, significant differences exist in the mechanical property of glulam and bamboo scrimber, which might lead to inaccurate estimations of the behaviour of bamboo scrimber structures. This paper describes the cyclic behaviour of exterior bamboo scrimber connections connecting I-beams and box columns. Four beam-to-column connections with welded steel angles and T-stubs were studied under reversed cyclic loading, and the influence of connection type and the number of bolts on the beam flange was considered. The load-displacement curve, failure mode, load capacity, ductility, stiffness degradation and viscous damping coefficient were obtained from the experimental results. Test results showed that connections with steel angles generally developed better ductility than those using T-stubs connecting the beam and column. When the number of bolts on the beam flange was increased, the energy dissipation of connections could be significantly increased. Besides, the shear resistance, distortion and strain of panel zones were studied, which could gain insight in the shear design of exterior connections. The contributions of the beam, column and panel zone to the total deformation of connections were analysed. Design recommendations were developed finally for application of bamboo scrimber beam-to-column connections in building structures. The experimental study provides valuable data for the design and practical application of this type of beam-column connection in building structures.