Theoretical and experimental analysis of two-culm bamboo beams

Guadua angustifolia is a species of bamboo native to South America. The aim of this study was to accomplish experiments and finite-element simulations to determine the stiffness of two-culm G. angustifolia beams, as typically used in the construction of low-rise buildings. Calculations were also accomplished to find the moment of inertia (i.e. effective) to assess beam deflections using a solid mechanics formula that includes bending and shear effects. First, full-scale tests of simple culms were performed with four different spans to find the axial and the circumferential–axial shear moduli. Next, full-scale tests of two-culm beams with two shear connectors located at L/6 from the supports were performed. There was a marginal increase of stiffness compared to that of two-culm beams without connectors. Finite-element simulations confirmed that the stiffness of two-culm beams with connectors is similar to that of two superimposed culms. Only the addition of cement mortar yielded an important increase of st...