恒定气候混凝土内钢筋锈蚀速率的时变特征与机理

为了深入研究混凝土中钢筋腐蚀龄期对钢筋锈蚀速率的影响，通过加速腐蚀试验研究了不变环境条件下混凝土中钢筋腐蚀电流强度的经时变化过程，并通过微观测试技术对混凝土中钢筋锈蚀层发展过程进行了机理分析，全面解释了钢筋腐蚀速率的经时变化过程规律．结果表明：钢筋表面锈蚀层（水泥浆体与铁锈物混合层）的形成与发展是钢筋锈蚀速率发生变化的主要原因；在气候环境条件恒定条件下，混凝土内钢筋的锈蚀速率的时变过程可分为锈蚀初期的下降阶段、平稳发展阶段和混凝土开裂后的上升阶段．

Change Characteristic and Mechanism of Rebar Corrosion Rate with Time in Concrete Under Constant Climate

To study the effects of corrosion time on the changing laws of rebar corrosion rate in concrete under constant climate,the time-variant rules of corrosion rate were researched using accelerated corrosion experiments.The process and mechanism of expansion process of rust layer were analyzed by scanning electron microscope and the time-dependent change rules of corrosion rate were proposed.The results show that the formation and development of rust layer (mixture of cement gel and rust) of steel/concrete interface are the main causes of rebar corrosion rate change;the developing process of corrosion rate in a constant climate condition can be parted into the three phases: the declining,the stable developing and the ascending after cracking.