锈损钢筋混凝土结构截面刚度衰变分析

Decay Analysis of Cross-Section Stiffness of Corroded Reinforced Concrete Structure

针对钢筋锈蚀导致的钢筋混凝土截面刚度衰变问题,基于Python语言,开发截面刚度非线性仿真程序,建立无损伤截面与损伤截面二维数值模型;分别考虑混凝土强度、截面尺寸与材料劣化导致的钢筋屈服强度降低、钢筋截面面积减小和混凝土截面损伤等问题,开展无损伤截面与损伤截面的弯矩-曲率关系计算分析,提出了考虑锈蚀率、混凝土强度与配筋率的截面刚度退化实用计算模型。研究结果表明:混凝土强度和截面尺寸影响无损伤截面刚度,截面尺寸相对刚度的影响更明显;钢筋锈蚀对损伤截面刚度的影响极为显著,随着锈蚀率的增加,截面开裂时和钢筋屈服时刚度不断减小,且开裂、破坏阶段提前发生;刚度退化实用计算模型可为钢筋锈蚀损伤混凝土结构性能检测评定提供参考。

Aiming at the problem of stiffness degradation of reinforced concrete cross-sections caused by corrosion of steel bars,a non-linear simulation program for cross-section stiffness based on the Python language was developed,and two-dimensional numerical models of non-damaged cross-sections and damaged cross-sections were established.Considering the concrete strength,the section-size and the reduction of yield strength of reinforcing bar,the reduction of reinforcing bar cross-section area and the damage of concrete cross-section caused by material deterioration,the moment-curvature relationship between non-damaged cross-sections and damaged cross-sections was calculated and analyzed,and a practical calculation model considering the degradation of cross-section stiffness including corrosion rate,concrete strength and reinforcement ratio was proposed.The calculation results show that the concrete strength and the section-size affect the stiffness of non-damaged cross-sections;relatively speaking,the influence of the section-size on the stiffness is more obvious.The influence of the steel corrosion on the stiffness of the damaged cross-sections is extremely significant.With the increase of the corrosion rate,the stiffness decreases when the section cracks and the steel bar yields,and the cracking and failure stages occur in advance.The proposed gradually practical calculation model of stiffness degradation can provide reference for the evaluation of the performance of corroded reinforced concrete structures.