Evaluation for Shear Resisting Mechanism of RC Beams Having Localized Corrosion in Longitudinal Reinforcement

本文对钢筋锈蚀损伤钢筋混凝土构件的抗剪机理进行了试验和分析研究。在试验中，研制了一种嵌入RC梁腹板混凝土的测量仪器，用于获取钢筋腐蚀状况对混凝土内部的影响信息。此外，实验中还采用了一种能够识别混凝土表面应变局部化的图像分析方法。试验结果表明，随着纵向钢筋的增加，腐蚀裂纹对决定性斜裂纹的萌生和扩展产生了影响。非线性分析表明，随着钢筋腐蚀的加剧，粘结性能下降，具有足够锚固配筋的钢筋混凝土梁的抗剪承载力增加。钢筋混凝土梁的这种行为可以通过晶格模型中拱单元的响应来解释，这些单元代表了梁中系拱机制的形成。

This study presents experimental and analytical investigations to evaluate the shear resisting mechanism of RC members damaged due to steel corrosion. In the experiment, a developed measurement instrument embedded in the web concrete of RC beams is used to obtain the internal information in the concrete being affected by the corrosion condition of reinforcement. In addition, an image analysis which can identify the localization of strain on the concrete surface is used in the experiment. The experiment shows the influence of corrosion cracks occurred along with the longitudinal reinforcement on the initiation and propagation of the decisive diagonal crack due to the further loading. Moreover, the nonlinear analysis shows that the shear carrying capacity of the RC beams having sufficient anchorage reinforcement increases when the bond property degrades as the steel corrosion proceeds. This behavior of the RC beams can be explained by means of the response of arch elements in the lattice model that represent the formation of the tied arch mechanism in the beam.