混凝土内钢筋锈蚀速率时变的全过程模式

讨论恒定气候环境下，混凝土内钢筋锈蚀速率的变化。在恒定气候环境和氯盐侵蚀条件下，对混凝土中钢筋的锈蚀电流密度进行测量。测量结果表明，在钢筋锈蚀过程中，锈蚀速率(锈蚀电流密度）具有时变特性，并且其时变过程可以划分为6个阶段。试验结果也显示了混凝土强度及混凝土电阻率对钢筋锈蚀速率变化的影响。基于不同锈蚀水平下钢筋与混凝土交界面过渡区(ITZ）的细观结构，开展了试验结果的机理分析，发现锈蚀层的发展和锈胀开裂是影响锈蚀过程的主要因素。最后，建立了钢筋锈蚀速率时变的全过程模式。

Time-variation full process mode of steel bar corrosion in concrete

This paper discusses the corrosion rate variation of reinforcing steels in concrete in constant climate environment. The corrosion current density of steel bar in concrete under a constant climate environmental condition and chloride attack. The results indicate that the corrosion rate (corrosion current density) of the steel bars is time-dependent during a corrosion process, and the time-dependent process can be divided into six phases in the full lifetime. The results also show that the effects of the concrete strength and the electrical resistivity of the concrete on the variation of the corrosion rate. This study conducts the mechanism analyses about the test results based on the microstructure of the interfacial transition zone (ITZ) between the steel bars and the concrete at different corrosion levels. The growth of the corrosion layer and the corrosion cracking are the main factors influencing the corrosion process. The time-variation mode of the corrosion rate of steel bars in full process is developed.