考虑表面氯离子质量分数的沿海混凝土桥梁氯离子扩散修正模型

发布时间：2018-05-02 08:47

本文选题：混凝土结构 + 氯离子扩散模型　；参考：《建筑科学与工程学报》2017年04期

【摘要】：为了研究沿海距海岸距离为5~40km钢筋混凝土桥梁的氯离子扩散规律,建立与之相适应的氯离子扩散模型,对沈山(沈阳—山关海)高速公路沿线25座钢筋混凝土桥梁进行钻芯取样,研究了表面氯离子质量分数和水胶比的关系。引入表面氯离子质量分数实测值与拟合值的比例系数,建立表面氯离子质量分数和距海岸距离的数学关系,结合氯离子表观扩散系数的时间效应对Fick第二定律的解析解进行修正。通过对比实测值和修正模型的拟合值验证模型的适用性。结果表明:构件表面氯离子质量分数与水胶比成正比,比例系数服从正态分布的统计规律;构件表面氯离子质量分数随着距海岸距离的增加而逐渐减小,二者呈指数关系;由修正后的氯离子扩散模型计算得出的拟合值能够包络大多数实测值,拟合结果偏安全。
[Abstract]:In order to study the chloride ion diffusion law of 5~40km reinforced concrete bridge with coastal distance from coast to coast, a corresponding chloride diffusion model was established. The coring samples of 25 reinforced concrete bridges along Shenshan (Shenyang-Shanguanhai) expressway were taken to study the relationship between surface chlorine ion mass fraction and water-binder ratio. The mathematical relationship between the surface chlorine ion mass fraction and the distance from the coast is established by introducing the proportional coefficient between the measured value and the fitting value of the surface chlorine ion mass fraction. The analytical solution of Fick's second law is modified by the time effect of the apparent diffusion coefficient of chloride ions. The applicability of the model is verified by comparing the measured value with the fitting value of the modified model. The results show that the mass fraction of chlorine ion on the surface of the component is proportional to the ratio of water to gel, and the proportional coefficient follows the statistical rule of normal distribution, and the mass fraction of chlorine ion on the surface of the component decreases gradually with the increase of the distance from the coast, which shows an exponential relationship. The fitting values calculated from the modified chloride diffusion model can envelop most of the measured values, and the fitting results are relatively safe.
【作者单位】：大连理工大学海岸和近海工程国家重点实验室;辽宁省交通规划设计院有限责任公司;辽宁大通公路工程有限公司;
【基金】：辽宁省交通科技项目(201512)
【分类号】：U441;U445.73

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