基于氯盐侵蚀的钢筋混凝土桥面板寿命预测  

Service Life Prediction of Reinforced Concrete Bridge Deck Under Chloride Attack

作　　者：张菊辉[1] 王伟[1] 管仲国[2] 

机构地区：[1]上海理工大学环境与建筑学院,上海200093 [2]同济大学土木工程学院,上海200092

出　　处：《材料导报（纳米与新材料专辑）》2016年第2期401-405,共5页

基　　金：国家自然科学基金(51408359;51378384);上海高校青年教师培养资助计划(ZZslg15064)

摘　　要：基于考虑温湿度耦合传导下的氯离子在非饱和混凝土内的渗透数值模型,以中国香港沿海处的某座钢筋混凝土高架桥为研究对象,预测临空区桥面板的腐蚀开始时间。系统分析了初始温湿度的变化、水灰比、保护层厚度及矿物掺合料对钢筋腐蚀开始时间的影响。结果表明:较高的初始温度和相对湿度能够延缓结构腐蚀开始时间;混凝土水灰比和保护层厚度是影响构件抗氯离子腐蚀的主要因素;添加粉煤灰或矿渣均能明显提高混凝土抵抗氯离子的侵蚀能力。提出氯盐侵蚀下钢筋混凝土桥面板腐蚀开始时间的简化公式,指出当水灰比小于0.4时,采用年平均值来表征环境变量边界条件的变化是比较合理的。Based on the chloride diffusion model coupled with temperature and humidity transfer in non-saturated concrete, a reinforced concrete viaduct located in Hong Kong marine environment was taken as a research object, and the corrosion initiation time of bridge deck exposed in air was predicted. The influence of change in the initial tem- perature, initial relative humidity, water-cement ratio and mineral admixtures on the corrosion initiation time was ana- lyzed. The results showed that a higher initial temperature and relative humidity can delay the corrosion initiation time. The water-cement ratio and concrete cover depth are main influencing factors on chloride ingress into concrete. Adding slag or flash ash into concrete can improve the capacity of concrete resisting the ingress of chloride. A simpli- fied equation to predict the corrosion initiation time for RC bridge deck under chloride environments was proposed. It was pointed that when the water-cement ratio is less than 0. 4, using the annual mean values to characterize the varia- tion of the boundary conditions of the environmental variables is reasonable.

关 键 词：温湿度耦合 腐蚀开始时间 氯离子 扩散模型 边界条件 

分 类 号：TU528.1[建筑科学—建筑技术科学]