偏心加载条件下钢筋与混凝土界面局部黏结参数的预测  

Prediction of local bond parameters of the steel-concrete interface under eccentric loading conditions

作　　者：庞瑞阳 杨树桐[1] 房恩惠 孙忠科 兰天 PANG Ruiyang;YANG Shutong;FANG Enhui;SUN Zhongke;LAN Tian(College of Engineering,Ocean University of China,Qingdao 266404,China)

机构地区：[1]中国海洋大学工程学院,山东青岛266404

出　　处：《四川建筑科学研究》2025年第1期10-19,共10页Sichuan Building Science

基　　金：国家自然科学基金项目(52178259);山东省自然科学基金重点项目(ZR2020KA001)。

摘　　要：考虑钢筋混凝土黏结界面的非均匀性和非连续性,针对试件不同的失效模式分别建立了确定局部抗剪强度τ_(f)和剪切断裂能G_(Ⅱf)的预测模型。通过对界面失效过程的分析,引入微观特征参数d_(eff)表征界面的非均匀性。此外,引入与剪切裂缝扩展相关的离散系数C以及与界面局部滑移相关的离散系数β,分别表征界面的非连续性。随后,采用钢筋偏心拔出试验,结合所提出的预测模型,探究了试件的失效模式以及偏心加载对黏结性能的影响。结果表明:局部黏结参数受混凝土保护层影响显著,但在不同失效模式下的变化规律存在区别;局部抗剪强度高于平均抗剪强度,且两者的差异随黏结长度的增加而变大;剪切断裂能对钢筋直径的变化更敏感。Considering the heterogeneity and discontinuity of the steel-concrete bond interface,a prediction model was established to determine the local shear strength(τ_(f))and shear fracture energy(G_(IIf))for various failure modes of the specimens.The micro-characteristic parameter(d_(eff))is introduced to characterize the heterogeneity of the interface by analyzing the failure process of the interface.In addition,a discrete coefficient C associated with shear crack extension and a discrete coefficient β associated with local slip at the interface are introduced to characterize the discontinuity of the interface,respectively.Subsequently,the failure modes of the specimens and the effects of eccentric loading on bond properties were investigated using the eccentric pullout test of steel bars in conjunction with the proposed prediction model.The results indicate that the local bond parameters are significantly influenced by the concrete cover,but there is variation in the pattern of change among different failure modes.The local shear strength is observed to be higher than the average shear strength,and the disparity between the two increases with the bond length.The shear fracture energy is found to be more sensitive to changes in the diameter of the steel bar.

关 键 词：变形钢筋 局部抗剪强度 剪切断裂能 黏结滑移模型 失效模式 

分 类 号：TU375[建筑科学—结构工程]