钢筋表面微区电位分布的原位测量

In-Situ Measurement of Potential Distribution on Surfaceof Reinforcing Steel in Simulated Concrete Pore Solution

应用自行研制的扫描微参比电极联机测量系统,原位测量了钢筋在模拟混凝土孔隙液中表面微区电位分布.结果表明,钢筋在纯饱和Ca(OH)2溶液中处于钝态.当溶液的pH降低和外加Cl-时,钢筋表面微区电位分布即发生变化,电位差变大,钢筋表面随之发生点腐蚀.

A scanning micro-reference-electrode technique controlled by micro-computer was used to (measure) the potential distribution on the surface of the reinforcing steel and to study the pitting initiation in early stage of the reinforcing steel in chloride-free and chloride-contaminated simulated concrete pore (solutions). The results showed that the reinforcing steel exhibited different corrosion characteristics in the different solutions. There were some unstable micro-pitting nuclei on the surface of the steel in the pure (Ca(OH)_2) solution and the steel remained passivated. However, the potential distribution on the surface of the reinforcing steel varied considerably and the pitting corrosion occurred on the steel when a sufficient quantity of Cl^- was added to the solution and pH fell.