箍筋锈蚀对RC框架柱耗能能力影响研究

Study on influence of stirrups corrosion on energy dissipation capacity of RC frame column

在钢筋混凝土构件中,箍筋不仅起着钢筋骨架的作用,而且约束构件的横向变形,改善其抗震性能。箍筋锈蚀后,其截面减小和力学性能变化会导致混凝土构件的破坏形式从延性向脆性转变。从约束指标和核心区混凝土抗压强度两方面改进约束混凝土的本构关系,合理反映箍筋锈蚀对核心区混凝土的影响。并借助OpenSees软件按此本构关系添加新材料对RC框架柱进行数值模拟,研究箍筋锈蚀对构件耗能能力的影响。最后与纵筋锈蚀引起的粘结退化对构件损伤的影响进行对比,发现箍筋锈蚀对构件的变形和损伤影响不可忽略。

In the reinforced concrete components, stirrups not only play the role of reinforced skeleton, but also constraint the lateral deformation of components to improve the seismic performance. Due to the reduction of cross-section and the change of mechanical property after stirrups corrode, the failure mode of reinforced concrete components changes from ductile to brittle. The constitutive relation of constraint concrete was improved from the perspectives of constraint indicator and the compressive strength of concrete core area, reflecting how the stirrup corrosion affects the performance of concrete core area reasonably. Then with the OpenSees software, a RC frame column was simulated using a new kind of material according to the constitutive relation to study how the stirrup corrosion affects the energy dissipation capacity of components. Finally, compared with the influence on component damage caused by the bond degradation owning to longitudinal reinforcement corrosion, it is found that the effects of change of stirrup corrosion on deformation and damage of the component cannot be ignored.