混凝土结构锈胀开裂预测的路径概率模型

针对氯盐环境下服役混凝土结构钢筋锈蚀、锈蚀程度不易检测及混凝土锈致开裂的现状,基于混凝土锈胀开裂过程的随机性,提出一种预测钢筋锈蚀、混凝土锈胀裂缝开展时变特性的概率模型,并编制了计算程序.该模型可以模拟混凝土中钢筋锈胀开裂发展进程的路径,有效评估氯盐侵蚀环境下混凝土结构中钢筋锈蚀状况和锈胀裂缝宽度不同时段的概率分布,同时能估计构件钢筋样本锈蚀百分比.通过对濒海环境下某混凝土桥下部结构的耐久性评估,验证了该模型的准确性.该模型实现了对服役混凝土结构耐久性能的有效预测,评估结果可为工程维修和加固提供理论依据.

Path probability model of corrosion-crack assessment for existing reinforced concrete structures

For the status that corrosion of reinforcement, indetectable corrosion degree and corrosion-induced crack of existing concrete structures in chloride-laden environment, a path probability model(PPM) to predict the stochastic corrosion crack development of reinforced concrete(RC) structures with time was proposed. The time-dependent probability distribution of steel corrosion ratio, crack width of concrete due to corrosion and percentage of corroded steel samples of elements were estimated effectively on a series of random paths of corrosion crack process simulated by computer programme. The substructure of an RC bridge in chloride laden environment was illustrated to verify the precise and effectiveness of the present model by the assessment result of field inspection data. The model can effectively predict the durability behavior of existing concrete structures and the predicted result is a reasonable proof for optimal strategies of maintenance and repair.