盐渍土环境下氯离子侵入混凝土模型研究  

Model of Chlorion Ingress of Concrete from Saline Soil

作　　者：乔頔[1] 夏文俊[2] 赵阳[2] 周欣[2] 徐永福[1] 

机构地区：[1]上海交通大学船舶海洋与建筑工程学院,上海200240 [2]江苏省交通工程建设局,江苏南京200002

出　　处：《公路交通科技》2011年第10期153-158,共6页Journal of Highway and Transportation Research and Development

基　　金：江苏省交通科研项目(09Y35)

摘　　要：氯离子侵入引发钢筋腐蚀,降低了盐渍土环境下钢筋混凝土结构物使用寿命。综合考虑混凝土孔隙溶液中氯离子的扩散、电迁移以及毛细吸附等运移方式,建立盐渍土环境下氯离子侵入混凝土模型,预测结构物寿命。采用有限元方法分析扩散电场、毛细作用对氯离子运移过程的影响。分析表明,多种离子运移产生的电场加速了氯离子的运移过程,且毛细作用在早期会使氯离子在混凝土表层累积。采用氯离子侵入模型,分析了保护层厚度对结构使用寿命的影响,建议连云港盐渍土环境下混凝土保护层厚度应不小于50 mm。Chloride ingress of reinforced concrete buried in saline soil will cause corrosion of interior steel and shorten service life. A comprehensive model which takes three mechanisms into account, including diffusion, migration and capillary absorption, was proposed to simulate the chloride transport process in concrete pore solution and predict the service life of reinforcement. The influence of electric field diffusion and capillary suction on chloride transport was analyzed by using finite element method. It is shown that the electric field generated by multi-ion transport will accelerate chloride ingress, and chloride will accumulate in the surface layer of concrete at early stage due to capillary suction. With the proposed model, the influence of cover thickness on service life was given. It is suggested that the thickness of concrete protective cover buried in saline soil in Lianyungang should be at least 50 mm.

关 键 词：环境工程 氯离子侵入 有限元法 盐渍土 钢筋混凝土 扩散电场 毛细作用 

分 类 号：U416.166[交通运输工程—道路与铁道工程] TU448[建筑科学—岩土工程]