重组竹-混凝土界面粘结-滑移本构模型

Bond-slip constitutive model of bamboo scrimber-concrete interface

为研究胶粘剂连接的重组竹-混凝土界面粘结性能及构建粘结-滑移本构模型,对44个重组竹-混凝土粘结试件进行单剪试验,并考虑了粘结长度、重组竹粘结宽度与厚度、混凝土强度及胶层厚度等因素对粘结性能的影响。研究结果表明:在不同影响因素下,试件破坏模式基本相同,均为混凝土表面发生剥离破坏,粘结界面间裂缝从加载端产生并向自由端发展,破坏过程分为弹性阶段、软化阶段和脱粘平台阶段;界面峰值剪应力随重组竹厚度、混凝土强度、胶层厚度增加而增大,随粘结宽度增加而减小。根据试验粘结-滑移曲线,建立了重组竹-混凝土界面粘结-滑移本构模型,与实验结果进行对比,该模型能较好地反映重组竹-混凝土界面剪应力与滑移量间的关系。

In order to study the bonding performance of bamboo scrimber-concrete interface connected by adhesive and construct bond-slip constitutive model,single shear tests were carried out on 44 bamboo scrimberconcrete bonding specimens.Plus,the effects of bond lengths,widths and thicknesses of bamboo scrimber,concrete strengths,and adhesive layer thicknesses on the shear performances of bond interfaces were also taken into consideration.The results of the study show that the failure modes of the specimens are almost the same under different influencing factors.That is,debonding failure occurs on the concrete surfaces,and the cracks between the bond interfaces develop from the loading stage to the free end.The failure process can be divided into elastic stage,softening stage and debonding platform stage.With the thickness of bamboo scrimber,the strength of concrete,and the thickness of glue layer increasing,the peak shear stress of the interface also increases;however,the peak shear stress decreases with the increase of the bonding width.According to the experimental bond-slip curve,a bond-slip constitutive model of bamboo scrimber-concrete interface was established.Compared with the experimental results,this model can better reflect the relationship between the shear stress and slippage of bamboo scrimberconcrete interface.