盐湖地区钢筋混凝土结构使用寿命的预测模型及其应用

根据Fick扩散定律，推导出综合考虑混凝土的氯离子结合能力，氯离子扩散系数的时间依赖性和混凝土结构微缺陷影响的新扩散方程，建立了用于预测混凝土使用寿命的氯离子扩散理论模型，用暴露于青海盐湖地区的C20和C40混凝土立方体试件对理论模型进行了实验验证，用在青海盐湖地区实际运行19a的钢筋混凝土结构对理论模型进行了工程验证，结果表明，本文理论模型的预测值与实测值非常吻合，而Fick第二扩散定律与实测值明显不符，此外，运用本文理论模型预测普通钢筋混凝土电杆在盐湖地区的使用寿命仅1．2a，而抗腐蚀钢筋混凝土电杆的使用寿命能够达到50a以上。

Prediction model for service life of reinforced concrete structures in salt lakes and its applications

Based on Fick's law of diffusion, a new multi component diffusion equation was deduced, in which the influences of concrete chloride ion binding capacity, time dependence of chloride diffusivity and micro defect of concrete structures were taken into consideration. On this basis a theoretical model of chloride ion diffusion for concrete service life prediction is obtained. Experimental evaluations were carried out based on C20 and C40 concrete cubes exposed in Qinghai salt lake, and field evaluations were carried out on basis of steel reinforced concrete structures which had been in Qinghai salt lake for 19a. Both evaluations proved that present model yielded good predictions for concrete exposed to salt lake, while predictions based on Fick's law of diffusion did not coincide with the test data. Furthermore, present model predicted a service life of 1.2a for ordinary steel reinforced concrete poles in salt lake while service life predictions for anti corrosion concrete poles might exceed 50a.