氯离子侵蚀环境下的RC梁退化概率模型

基于现有规范的抗力计算公式,采用Monte Carlo数值模拟方法建立了由氯离子侵蚀引起的钢筋锈蚀下的RC梁抗力时变退化概率模型.模型考虑了混凝土、箍筋、斜筋和主筋对结构抗力的贡献,以及钢筋锈蚀过程对结构性能的影响,其对分析和评定服役混凝土结构的可靠性提供了一定借鉴意义.研究表明：保护层厚度对钢筋锈蚀初始时间影响显著,构件在65年以前受剪抗力退化更快,而在65年之后受弯抗力退化更快.

Degenerated probabilistic model of RC beam under chloride environment

In this paper,based on the existing standard formulas, the probability model of RC beam degradation of bearing and resistance capacity is established by using Monte Carlo numerical simulation under the environment that steel-bar corrosion results from the chloride. It considered the contribution of concrete, stirrups, diagonal bars and longitudinal bars to structure resistance ,and the effect of the progress of steel corrosion on the structure performanceo It is beneficial to analyze and evaluate the reliability of old concrete structure as a reference. The results show that, the depth of the concrete cover has a marked effect on initiation time of reinforcement bar corrosion. The shear capacity of member will degrade faster in the previous 65 years,and the flexural capacity of member will degrade faster after that.