关键词: 桥梁工程, 钢筋混凝土梁, 抗弯性能, 加速锈蚀试验, 劣化分析, 承载能力评估

Abstract: In order to effectively predict the deterioration rule of the flexural behavior of the corroded reinforced concrete beams (RC beams), the flexural behavior study on three groups of RC beams was conducted based on accelerated corrosion method. The influence of different longitudinal reinforcement corrosion rates on the failure mode, strain distribution and load deflection curve of RC beams was discussed. Based on the applicability evaluation of the existing theoretical models, combined with the time-varying material analysis model, an analysis method for the degradation rule of flexural bearing capacity of RC beams was proposed. The results show that with the increase of corrosion degree of longitudinal bars, the plastic deformation characteristics of RC beams continuously decrease, and the failure mode changes from pure plastic bending to brittle shear bending. As the neutral axis of the mid-span section moves upward, the assumption of plane section cannot be satisfied gradually. Moreover, the flexural bearing capacity of the beam decreases continuously, and the bearing platform of load-deflection curve gradually becomes shorter until it disappears. According to the applicability analysis of the existing bending capacity models, it is found that the calculation accuracy of Sun Bin model is the highest and the discreteness is the least. The deterioration analytical method of flexural behavior of RC beams based on the Sun Bin model can obtain the deterioration curves which are in good agreement with the experimental results.

Key words: bridge engineering, reinforced concrete beams, flexural behavior, accelerated corrosion experiments, deterioration analysis, assessment of load-carrying capacity