碳化概率模型及混凝土结构碳化失效概率分析

Probabilistic carbonation model and carbonation failure probability assessment of concrete structures

混凝土碳化分析是评估混凝土结构长期性能的重要内容。该文分析总结了现有混凝土碳化理论和经验模型。在现有确定性模型基础上,通过添加模型修正项的方法修正确定性模型的误差,建立混凝土碳化概率模型。概率模型中模型参数的后验统计分布特征利用已有检测数据通过贝叶斯更新手段获得。基于建立的碳化概率模型,构建混凝土结构碳化时变失效概率的分析方法,该方法充分考虑模型不确定性对混凝土结构碳化时变失效概率的影响。运用该方法对一钢筋混凝土简支板的碳化性能进行了分析评估。

Concrete carbonation analysis is of vital importance for the long-time performance assessment of concrete structures. In this work, the theoretical and empirical concrete carbonation models in current use are investigated. By adding model correction terms to the deterministic model and correcting the potential bias in the deterministic model, the probabilistic carbonation model is constructed. The posterior statistics of the model parameters are computed through the Bayesian updating approach based on the field test data of concrete carbonation. The corresponding time-variant probability analysis for the concrete carbonation process is established based on the developed probabilistic model. The influence of the model uncertainty on the concrete carbonation failure probability is taken into consideration. Furthermore, the above process is applied to a simply supported concrete slab to evaluate the carbonation performance of this concrete structure.