近海大气环境下锈蚀RC框架节点抗震性能试验研究

为研究近海大气环境下锈蚀RC框架梁柱节点的抗震性能,该文设计了6个RC框架梁柱节点试件,采用人工气候加速腐蚀技术对试件进行了加速腐蚀试验,进而对试件进行了拟静力加载试验,获得了不同钢筋锈蚀程度和轴压比下梁柱节点的破坏形态及抗震性能衰减规律。试验结果表明：对于梁柱节点构件,箍筋锈蚀较纵筋严重,由于锈蚀箍筋对节点核心区混凝土的约束削弱,节点区域破坏程度加重;随钢筋锈蚀率的增大,试件的强度、延性及耗能能力均发生不同程度的退化,表现为构件承载和变形能力的降低;锈蚀程度相同时,随轴压比的增大,试件的刚度退化更加显著,轴压比较小的试件在开裂前刚度退化明显,屈服后趋于稳定。

Experimental research on seismic behaviors of beam-column joints of corroded RC frame in the coastal atmosphere

In order to study the seismic behaviors of beam-column joints of corroded RC frame in the coastal atmosphere, the accelerated corrosion tests for 6 beam-column joint specimens of RC frame were conducted by applying the technique of artificial climate accelerated corrosion, and the quasi-static tests were then carried out. The failure modes and seismic degradation characteristics of joints were obtained under different corrosion degree and axial compression ratio. The results showed that for corroded joints, the corrosion degree of stirrups was more serious than that of longitudinal reinforcement, and as a result of the reduced constraint of corroded stirrups, the severe damage of joints can be observed. With the increase of corrosion rate of stirrups, the strength, ductility, energy dissipation, bearing capacity and deformation capacity of joints degenerated with different extents. When the corrosion degree was same, the stiffness degradation appeared to be more apparent with the increase of axial compression ratio. It was also shown that the stiffness degradation was serious before cracking for the joints with small axial compression ratio, and then tended to be stable after yielding.