Abstract: The bending performances of 21 bamboo plyboard enhanced glue-lumber beams were studied. Under the effects of bamboo plyboard layer number and thickness, the timber beam failure modes, ultimate load and mid-span deflection parameters were analyzed. Experimental results show that, compared to pure glue-lumber beams, the failure load of beams, with 1-3 layers of scuffing bamboo plyboard on the bottom, is increased by 16.8% ~ 45.9%. With the increase in the number of bamboo plyboard layers, the deformation capacity of the beams becomes stronger. However, the intercalated sliding becomes more obvious, which makes the bearing capacity of the beams decreases instead of increases. When the total thickness of the bamboo plyboard remains the same, the decrease in the thickness of each layer bamboo plyboard has no obvious influence on the failure modes of glue-lumber beam reinforced by bamboo plyboard. The total deformation is obvious and the ductility increases. The span-section strain of reinforced glue-lumber boards accords with the plane section assumption. The glue-lumber on the top of the beams reaches the compressive strength and has a certain plastic height when failure occurs. The scuffing-bamboo on the bottom of the beams reaches to the ultimate tensile strain. A formula to calculate the flexural capacity of the bamboo plyboard enhanced glue-lumber beams was put forward, which was verified. The optimum ratio of the thickness of the bamboo plyboard was given.

Key words: civil engineering, bamboo plyboard enhanced glue-lumber beam, bending performance, failure mode, bearing capacity calculation