混凝土中钢筋锈蚀深度预测模型

Prediction Model on the Rebar Corrosion Depth in Concrete

通过对在自然环境下经历2 a干湿循环作用的锈蚀钢筋混凝土试件的试验研究,探讨了保护层锈胀开裂后钢筋的锈损程度及其影响因素.依据试验结果,运用数理统计相关知识,对试件的锈蚀特征进行分析,建立了与保护层厚度、表面裂缝宽度、钢筋直径、混凝土强度等级及箍筋间距相关的混凝土中钢筋锈蚀深度预测模型;对模型进行参数敏感性分析表明,表面纵向锈胀裂缝宽度是影响钢筋锈蚀深度的最主要因素,除其他因素外,箍筋间距对纵向钢筋锈蚀深度也具有一定影响,且随箍筋间距减小影响程度逐渐显著;经试验验证,所建立模型具有较强的适用性.

By the wet-dry cycle test on reinforced concrete specimens under natural conditions for two years,corrosion degree of rebars after concrete cover cracking and its influencing factors were measured. Based on the test results,applying the knowledge of mathematical statistics to analyze the corrosion characteristics of samples,a prediction model for the corrosion depth of reinforcement was established in relation to the concrete cover thickness,surface cracks width,bar diameter,concrete strength,stirrup spacing, and so on.The sensitivity analysis to model parameters shows that crack width on the surface is the most important factor for the corrosion depth of steel;stirrup spacing also has a significant effect on the corrosion depth of longitudinal reinforcement;the smaller the stirrup spacing is,the more remarkable the effect is.The experimental data show that the model is of good applicability.