An investigation of the flexural performance of bamboo-concrete composite beams with precast light concrete slabs and dowel connectors

Bamboo-concrete composite (BCC) beam is an attractive structural system due to the synergistic use of bamboo and concrete components. To reduce the weight and achieve industrial production of such beams, this paper presents a novel BCC beam with precast lightweight concrete slab, which could be referred to as an assembled bamboo-lightweight concrete composite (ABLCC) beam or semi-ABLCC beam. In this paper, the shear performance of an ABLCC connection system was investigated first. The experimental variables include the diameter of the dowels and the manufacturing processes of the specimens. The test results showed that the ABLCC connection system had a similar shear strength but a higher stiffness than the cast-in-place bamboo-lightweight concrete composite (PBLCC) connection system. Increasing the diameter of the dowels improved the shear capacity of the systems. Then the flexural performance of ABLCC beams was investigated. Experimental parameters, including the diameter of the dowels, the spacing of the dowels, and the manufacturing processes of the specimens, were taken into consideration in the bending tests. The failure mode of the ABLCC beams was tensile fractures of the bamboo fibers at the bottom of the beam and crushing of the concrete under the loading point. The ABLCC beams had remarkable properties in terms of the bending capacity and flexural stiffness, which were 1.49–1.96 times and 2.18–3.47 times higher than those of the bamboo beams, and 1.11 times and 1.09 times higher than those of the PBLCC beams, respectively. The bending capacity, flexural stiffness and combination efficiency of the ABLCC beams decreased with increasing dowel spacing. The results of analytical methodologies used to predict the mid-span deflection of the ABLCC beams were in good agreement with the test results.