胶合竹植筋深度及直径对抗拔性能的影响

采用胶合竹梁、双组份环氧树脂胶黏剂,不同直径和长度的公制螺纹杆,进行胶合竹顺纹双端植筋拉伸试件制备及测试,初步分析研究了植入深度和植筋杆直径2个因素对胶合植筋强度和破坏模式的影响。抗拉试验破坏模式主要为植筋杆的拔出破坏和螺纹杆的韧性断裂破坏2种模式,其中植筋杆的拔出破坏位于胶合竹/胶黏剂界面;胶合竹顺纹双端植筋的破坏载荷及名义剪切强度随螺纹杆直径和植入深度增加而增大;胶合竹基材较胶合木基材渗透性差,植筋杆受力不能很好地传递到竹材内部,是影响抗拔载荷主要因素之一。

Effects of the glued-in threaded rod depth and diameter on the connection strength of structural glued laminated bamboo

Through the both-end pullout test on the glued-in threaded rods in bamboo plywood, the effects of the depth and the diameter of the embedded rods in the bamboo glulam on the connection strength and the failure modes were investigated. Two failure modes were identified during the pullout test: the fracture of threaded rods and the pullout failure of the rods that existed in the interface between bamboo and the adhesive. The pullout critical load and the normal shear strength of both-end glued-in rods in bamboo plywood increased with an increase of the diameter and embedded length of the threaded rods. In addition, the low stress transfer efficiency caused by the poor permeability of bamboo is the main reason for hindering the further improvement of the connection strength of bamboo plywood composites.