混凝土中钢筋的腐蚀行为及腐蚀速率预测

结合理论分析、数值模拟和试验验证,探讨了混凝土中钢筋的腐蚀行为,并建立了钢筋腐蚀速率的预测模型.首先基于试验数据,修正了混凝土的电阻率模型,然后结合混凝土中钢筋腐蚀的电化学原理和宏电池腐蚀模型,分析了保护层厚度、水灰比、氯离子含量和空气相对湿度等因素对钢筋腐蚀过程控制方式和腐蚀速率的影响,并据此建立了混凝土结构钢筋腐蚀速率的预测模型.分析表明,所建立的预测模型能够合理地反映电阻和阴极控制条件下钢筋腐蚀速率的变化趋势,具有较好的预测精度和实用性.

Corrosion Behavior and Prediction of Corrosion Rate for Steel Bar in Concrete

Corrosion behavior of steel bar in concrete was investigated and a prediction model for corrosion rate was developed with commonly used engineering parameters based on theoretical analysis, numerical simulation and experimental validation. An improved model for concrete resistivity was proposed by fitting the experimental data first. Then the influences of water cement ratio, chloride content, cover depth and relative humidity on the control mode of corrosion process and the steel corrosion rate were investigated according to electrochemical mechanism and macro cell corrosion model. Finally, a prediction model for corrosion rate was proposed based on the nonlinear regression with commonly used engineering parameters. Analysis results demonstrate that the proposed model could reflect the variation trend of corrosion rate under both resistivity and cathodic control modes with desirable accuracy and practicality.