盐渍环境地铁混凝土结构耐久性设计

Concrete Durability Design for Metro Station in Saline Environment

以西宁市某地铁车站为例,结合盐渍环境下混凝土结构腐蚀机理分析,综合近年来的试验研究及工程实践,高性能混凝土中添加粉煤灰、硅灰等矿物掺和料更适用于盐渍地区的地铁车站结构。根据地铁车站的自身特点和明挖顺作工法要求,混凝土耐久性设计采用"内增外防"的综合防水防腐措施。提出适用于盐渍环境下地铁明挖车站的结构混凝土强度等级和相适应的掺加料用量指标、混凝土耐久性控制技术指标以及结构附加防腐措施,为盐渍环境下地下工程建设提供借鉴和参考。

Taking a metro station in Xining as an example,through corrosion mechanism analysis of concrete in saline environment,based on experimental study and engineering practices recent years,the paper thinks that the high performance concrete containing fly ash and silicon ash or other mineral admixture is more suitable for metro station structure in saline areas.According to the feature of metro station structure and requirement of open cut and cover method(the main techniques adopted in urban metro construction),comprehensive waterproof and anticorrosion measures were applied to concrete durability design of this example.In this paper,concrete strength grade,amount of adding materials,concrete durability control indexes and additional anticorrosion measures are proposed for open-cut metro station structure in saline environment.It also provides reference for underground engineering construction in saline environment.