Experimental and analytical investigations on flexural behavior of bamboo beams strengthened with steel bars

The embedding of steel bars is proposed to enhance the load-bearing performance of bamboo beams. Based on laboratory tests, the bending behavior of bamboo beams reinforced with steel bars or prestressed steel bars was analyzed using finite element software. Comparing the finite element simulation results with those measured in tests, it can be found that the load–displacement curves coincide with each other, and the strain development processes in the mid-span are basically the same. The prediction by the finite element simulation has good accuracy. The embedding of steel bars and prestressed steel bars can effectively improve the ultimate bearing capacity (up to 27.0%), bending stiffness at the serviceability limit state (up to 42.61%), ductility (up to 22.9%), and material utilization efficiency (up to 34.1%) for the bamboo beams. The embedding of steel bars makes the bamboo in the compression zone of the beams develop with higher efficiency, and applying the prestress for steel bars can produce reverse bending deformation and reduce the actual deflection for the reinforced bamboo beam under service load. Under the same reinforcement ratio, the prestress level has a relatively small influence on the ultimate bearing capacity (up to 4.5%) and stiffness (up to 4.5%) of the reinforced beam.