水灰比对水工混凝土中钢筋锈蚀的影响

通过电化学试验方法,探讨了非开裂状态下混凝土水灰比对混凝土中钢筋锈蚀的影响规律,以研究钢筋锈蚀破坏引起的水工混凝土结构失稳破坏.研究表明,降低水灰比,可以延长钢筋开始锈蚀的时间;进入稳定锈蚀阶段后,水灰比越小,稳定腐蚀电流密度就越小,水灰比与稳定腐蚀电流密度存在一定的函数关系,且数据相关性良好;降低水灰比能有效改善混凝土.钢筋界面区的微观结构,降低了界面区的氧气含量,同时也减少了界面区的毛细孔水及层间水含量,氧气和水含量的减少降低了钢筋锈蚀速率.

Influence of ratio of water to cement on corrosion of steel bar in hydraulic concrete

To study the destruction of hydraulic concrete structure resulting from the corrosion of steel bar, the influence of ratio of water to cement (W/C) on corrosion of steel bar in concrete without cracks were carried out using electrochemical tests. The results showed that the corrosion of steel bar was delayed at low W/C. It also showed that at stable corrosion time, the W/C had a well function relationship with stable corrosion current density. Further studies showed that with low W/C, concrete microstructure was compacted effectively decreasing of oxygen, capillary water, and interlayer water on the interface of concrete and steel bar, which was beneficial for preventing from the corrosion of steel bar. Therefore, reducing the ratio of water to cement can effectively delay the corrosion of steel bar reinforced concrete without cracks.