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依据电化学原理 ,考虑了混凝土碳化规律以及钢筋锈蚀后半径变化对预测钢筋锈蚀率的影响 ,同时把氧化在混凝土中的扩散系数视为随时间变化的变量 ,提出了一个新的预测模型 ,并通过分析这一模型产生误差的原因 ,提出了用模型因子对预测公式进行修正 .同时 ,理论分析表明 :采用一般的混凝土碳化表达式与采用简化的混凝土碳化表达式相比 ,钢筋锈蚀率预测值会有显著差别 ;而考虑钢筋半径随锈蚀率的增加而减小以及氧气在混凝土中扩散系数随时间变化更符合实际情况 ;另外 ,在同一混凝土构件中 ,箍筋锈蚀程度要比纵筋更为严重 ,这就要求我们重视混凝土结构的抗剪耐久性的失效问题
According to the electrochemical principle, considering the law of carbonation of concrete and the change of the radius after corroded steel, the influence of the corrosion rate on the prediction of rebar corrosion is considered. At the same time, the diffusion coefficient of oxidation in concrete is regarded as the variable with time, a new prediction model is proposed. By analyzing the cause of the error in this model, a model factor is proposed to correct the prediction formula.At the same time, the theoretical analysis shows that compared with the simplified concrete carbonization expression, the prediction value of corrosion rate of steel bar There is a significant difference; considering the reinforcement radius decreases with the increase of corrosion rate and the diffusion coefficient of oxygen in concrete with time more in line with the actual situation; In addition, the same concrete components, stirrups corrosion degree more than longitudinal reinforcement Serious, which requires that we pay attention to the failure of shear resistance of concrete structures