基于颗粒流的新老混凝土加固构件轴压性能细观研究  

Meso-study on the axial compression performance of new and old concrete reinforced members based on particle flow

作　　者：姜仲洋 李志华[1] 张聪[1,2] JIANG Zhongyang;LI Zhihua;ZHANG Cong(School of Environment&Civil Engineering,Jiangnan University,214122 Wuxi,China;State Key Laboratory of Green Building Materials,100024 Beijing,China)

机构地区：[1]江南大学环境与土木工程学院,无锡214122 [2]绿色建筑材料国家重点实验室,北京100024

出　　处：《应用力学学报》2022年第2期342-349,共8页Chinese Journal of Applied Mechanics

基　　金：国家自然科学基金资助项目(No.51908247);江苏省自然科学基金资助项目(No.BK20170192);绿色建筑材料国家重点实验室开放基金资助项目(No.YA-616)。

摘　　要：考虑到混凝土是一种非均质材料,为研究新老混凝土界面黏结特性和破坏机理,利用PFC3D细观离散元软件对新老混凝土黏结试块双面剪切性能和增大截面法加固钢筋混凝土构件轴压力学性能进行数值研究。结果表明,对于双面剪切试验,新老混凝土剪切-位移数值曲线与试验曲线基本一致,模型接触断裂主要发生在新老混凝土界面处,裂缝数量随着模型达到峰值后急剧上升,在界面处形成贯通的断裂面;在轴压试验模拟中,轴压力、混凝土应变关系数值曲线与试验结果吻合较好,数值结果能较好地预测软化阶段,模型中接触断裂主要发生在柱中部及下部位置,与实际破坏模式相符。Considering that concrete is a kind of heterogeneous material,in order to study the interfacial bonding characteristics and failure mechanism of new and old concrete,PFC3 D mesoscopic discrete element software was used to simulate the double-sided shear performance of new and old concrete specimens and the axial compression mechanical properties of reinforced concrete members strengthened by increasing section method.The results showed that in the double-sided shear test,the numerical curve of shear displacement of new and old concrete is basically consistent with the test curve,the contact fracture of the model mainly occurs at the interface of new and old concrete,and the number of cracks increases sharply after the model reaches the peak value,and a transfixed fracture surface is formed at the interface.In the simulation of axial compression test,the numerical curve of the relationship between axial compression and concrete strain is consistent with the experimental curve,and the numerical simulation can well predict the softening stage.The contact fracture mainly occurs in the middle and lower parts of the column,which is consistent with the actual failure mode.

关 键 词：离散元法 新老混凝土 界面破坏 细观 加固 

分 类 号：TU317[建筑科学—结构工程]