带肋钢筋-混凝土界面黏结破坏行为细观模拟

Mesoscale modelling of bond failure behavior of ribbed steel bar and concrete interface

钢筋与混凝土之间的良好黏结是钢筋混凝土结构共同承载受力的基本前提.结合混凝土细观结构及带肋钢筋结构特征,考虑钢筋与混凝土间摩擦阻力及机械咬合作用的影响,建立了带肋钢筋与混凝土界面非线性黏结破坏行为研究的细观尺度分离式相互作用模型.在与已有试验结果吻合良好的基础上,首先讨论了细观力学分析方法的优势,研究了钢筋-混凝土界面黏结-滑移行为与破坏机制,分析了钢筋黏结应力的分布特征.进而基于细观数值分析方法讨论了骨料分布、保护层厚度、混凝土强度等级、钢筋直径和钢筋肋高等因素对钢筋-混凝土界面黏结破坏行为的影响规律,得到了一些规律性认识.

The good bond between rebar and concrete is an essential prerequisite for the bearing force of reinforced concrete structures.In the simulation method,the concrete heterogeneity and rebar characteristics were taken into account.Considering frictional resistance and the mechanical interlocking between reinforcement and concrete,the paper established meso-scale separate interaction model which researches the nonlinear bonding damage behavior ribbed bar and concrete.Based on the good agreement between the simulation results and the experimental results,the advantages of the mesoscopic mechanical analysis method were discussed first,and the bond slip behavior and failure mechanism of the reinforced concrete interface were studied.Finally,the distribution characteristics of the bond stress of the bar was analyzed.Furthermore,based on the mesoscopic numerical analysis,the influences of the aggregate distribution,thickness of concrete cover,strength of concrete,steel bar diameter and height of rib on the bond failure behavior of reinforced concrete interface are discussed,and some regular knowledge is obtained.