荷载与氯化物耦合作用下高性能混凝土中钢筋锈蚀试验

Experimental study of steel bars corrosion in HPC affected by load and chloride

为研究高性能混凝土（HPC）在通电加速锈蚀环境下,氯离子侵蚀和荷载耦合作用对其中钢筋锈蚀影响的规律和机理,以粉煤灰单掺、粉煤灰与矿渣复掺、阻锈剂以及应力水平为变量因素,设计了12组HPC配合比并分别制作内置两根钢筋的小梁试件.采用PARSTAT 4000电化学工作站对混凝土内钢筋进行腐蚀速度测试,并通过观测腐蚀产物更直观掌握钢筋的锈蚀情况.试验结果表明,荷载明显地增加了试件中钢筋的锈蚀程度;掺入不同矿物掺和料和阻锈剂可以明显改善HPC中钢筋的锈蚀情况,降低钢筋的失重率,其保护层最大开裂宽度也得到明显控制.在试验基础上提出了具有高抗锈蚀性能的高性能混凝土配合比建议,为工程应用提供技术支持.

To investigate the rule and mechansim of the rate and extent of steel bars corrision in high performance concrete（HPC）,12 HPC mix proportions spesimens（considered fly ash,slag and anti-corrosion admixtures）are designed and every concrete specimen prism is inserted with two embedded steel bars and the steel bars are connected to external direct current techniques to accelerate the corrision.To measure the rate of corrision,eletrochemical methods are used.For intuitive perception,observations of the corrosion products are conducted.The results show that the load increases the corrosion rate of steel bars in concrete apparently.The extent and rate of corrision changes from different mineral admixtures and anticorrosion admixtures,as well as the maximum width of crack of the protective layer.The experimental results in provide technical supports for engineering applications.