Comparative investigation on beam-to-beam connection with different types of connecting plates

Abstract

The spliced glued laminated timber (glulam) beams have extensive applications in large-span timber structures since the length of the long solid wood beams is limited by transportation and construction. This paper investigated the flexural performance of glulam beam-to-beam connections with connecting plates and self-trapping screws. The influence of connecting plate types (steel plate, bamboo scrimber, and plybamboo plate) on the flexural performance of the spliced beams was studied. A total of 12 beams were designed, including the intact beam group (3 specimens) and the spliced beam group (9 specimens). The failure modes, ultimate bearing capacity, stiffness, moment-rotation curves, and carbon emissions of spliced beams with different connecting plates were studied. The test results showed that the failure mode of the spliced beams mainly included bending failure of glulam and fracture of the connecting plates. The average bearing capacity of the spliced beams with bamboo scrimber plates and those with steel plates could reach the intact beams. The average stiffness of the spliced beams with bamboo scrimber plates was higher than that of the splice beams with steel plates, reaching 97.6% of the intact beams. The average bearing capacity and stiffness of the splice beams with plybamboo plate reached 80.9% and 92.7% of the intact beams, respectively. A theoretical model of the spliced beams with bamboo scrimber plates was proposed and verified by tests data. Comparisons of the analytical and the test results reveal that the model can predict the moment capacity of the spliced beams with bamboo scrimber plates corresponding specific failure mode in this test.