单波 邓钧远 叶芯 肖岩

摘   要：基于已有的推出试验，选择螺杆、凹槽和预紧力凹槽3种连接件，开展了5根胶合竹-混凝土组合梁的四点抗弯试验，研究连接件类型与数量对组合梁抗弯性能的影响. 试验结果表明，组合梁具有较高的初始组合效应，在正常使用极限状态内的组合效应相对稳定，且组合梁的抗弯刚度和承载力随连接件数量增加而提高;对于采用螺杆连接件的组合梁，其极限承载力取决于指接部位的抗拉强度;对于凹槽类连接件的组合梁，其极限承载力主要由端部连接件的抗剪切强度控制;采用预紧力凹槽连接件的半装配式组合梁与现浇施工方式的凹槽组合梁相比较，其抗弯性能很接近，但施工效率显著提高;欧洲规范EC 5中的等效截面刚度法高估了试件的承载力，不适合直接套用于组合梁.

关键词：组合梁;胶合竹;抗弯性能;组合效应

中图分类号：TU398.4                  文献标志码：A

文章编号：1674—2974（2021）01—0154—09

Abstract：Based on the existing pull-out tests on shear connectors， total five glued laminated bamboo （glubam）-concrete composite beams were tested under four-point bending loading to investigate the effect of connector type and numbers on the bending performance of composite beams. Three types of connector were selected in the current study including the screw connector，the notch connector and the pre-tightening notched connector. Test results show that all composite beams with different connectors exhibit high initial composite action and relatively stable composite action under the serviceability limit state. For the composite beams with screw connectors， the ultimate load carrying capacity is determined by the tensile strength of the glubam at the fingure joint. However， the ultimate load carrying capacity of the composite beams with notch connectors and the pre-tightening notched connectors mainly relied on the shear strength of the end connector. The semi-prefabricated composite beam with pre-tightening notched connectors shows the similar bending capacity when compared with the corresponding casting in-situ composite specimen， indicating a good prospect considering its high construction efficiency. The equivalent stiffness method predicted by Eurocode 5 overestimates the load carrying capacity of all specimens， and it is not suitable for glubam-concrete composite beams.

Key words：composite beams;bamboo;bending performance;composite action

我國木材资源匮乏，国内所需的木材严重依赖进口的方木和原木，这严重制约了我国现代木结构的发展. 但我国竹林资源丰富，尤其是具有丰富的大径级毛竹. 对毛竹进行破片重组胶合，制成高强度的工程竹材，并用于建筑结构，成为绿色建筑领域的研究热点[1-2].

胶合竹（glued laminated bamboo）是由单向竹帘正交层叠、热压胶合而成的一种工程竹材，最早由肖岩等[3-4]提出并开展研究. 为了与国外广泛应用的胶合木（glulam）相对应，肖岩等将胶合竹命名为glubam，目前已在竹木结构研……