An experimental study on shear strength of glubam

Glued-laminated bamboo (glubam) is a new type of structural material, which is developed as a potential alternative to the glued-laminated lumber or glulam. Similar to modern timber structures, connecting the glubam elements using steel joints requires a good understanding of the shear behavior of the material. In this study, glubam boards with three different bamboo strip (or fiber) configurations are manufactured and studied. Three types of glubam boards were manufactured and tested, including glubam with two bidirectional fiber arrangements at the ratios of 4:1 and 1:1, respectively, in the two orthogonal directions, and also the unidirectional fiber arrangement. The shear strengths in different loading conditions are experimentally investigated, following testing specifications for conventional wood. The study found that the in-plane shear strength values follow a normal distribution well, whereas the out-of-plane shear strength values can be statistically expressed by Weibull distribution. Based on the test results, the out-of-plane shear strengths and the in-plane shear strengths of glubam are studied, and the characteristic values and the design values are suggested. The relationship between the out-of-plane shear strength and the bidirectional ratio of bamboo strip (or fiber) has also been obtained with reasonably good correlation to the test results.