Experimental study on bearing capacity performance of glued bamboo-wood bolted joints

Abstract

The paper presented an experimental investigation of glued bamboo-timber bolted joints to study the influence of bolt grade, bolt diameter, and material type on the load-bearing capacity of bolted joints. The results showed that the failure mode of glued bamboo-timber bolted joints was characterized by compression deformation of the bolt holes, with a plastic hinge failure occurring at each shear plane. Additionally, the failure of the specimens involved the failure of both the primary material and the adjacent substrate at the edge of the joint. As the diameter of the bolts increased, the load-bearing capacity of the specimens also increased. The increase in maximum load from a bolt diameter of 10 mm to 12 mm was 13.78 %, while the increase in maximum load from a bolt diameter of 12 mm to 14 mm was 42.29 %. Enhancing the bolt grade increased the load-bearing capacity of the specimens. The increase could be 10.32 % under the circumstance of WBW (wood on the outer layer and bamboo on the inner layer) combination while 8.4 % when it was BWB (bamboo on the outer layer and wood on the inner layer) combination. Moreover, when the material type was changed into BWB, the increase in load-bearing capacity was 55.33 % and 32.84 % when the diameter varies. The load-bearing capacity of the BWB material was higher than that of the WBW material. After comparing the existing methods of calculating bolt load carrying capacity, optimizations were made to the calculation formulas in Eurocode 5. The modified formula provided more accurate predictions of the load-bearing capacity of glued bamboo-timber bolted joints.