高地温对混凝土氯离子渗透性能影响分析

混凝土的抗氯离子渗透性是混凝土耐久性的一个重要指标,影响到引水隧洞等工程的使用寿命。为获得高地温对混凝土氯离子扩散的影响规律,在电通量法获得不同养护温度条件下,混凝土的抗氯离子渗透实验结果的基础上,采用非线性氯离子吸附模型与温度耦合的数值计算方法,分析了不同温度梯度条件下混凝土氯离子扩散规律。结果表明:20～60℃混凝土抗氯离子渗透性能随温度升高而增强; 60～90℃抗氯离子渗透性能随温度升高而迅速降低;随时间的推移自由氯离子在混凝土中呈非线性扩散且深度不断增大,直至穿透混凝土。因此,进行氯离子在混凝土中的扩散分布研究,可以客观地预测混凝土的服役寿命。

Analysis of Influence of High Ground Temperature on Permeability of Concrete Chloride Ion

The chloride ion permeability of concrete is an important indicator of concrete durability, which affects the service life of water diversion tunnels and other projects. In order to obtain the influence of high ground temperature on the chloride ion diffusion of concrete, the numerical calculation method of nonlinear chloride ion adsorption model and temperature coupling is used based on the experimental results of chloride ion penetration resistance of concrete under different curing temperature conditions. The diffusion law of chloride ion in concrete under different temperature gradient conditions was analyzed. The results show that the chloride ion penetration resistance of concrete at 20~60°C increases with the increase of temperature; the chloride ion penetration resistance of 60~90 °C decreases rapidly with the increase of temperature; Free chlorine ions diffuse non-linearly in concrete over time and the depth increases until it penetrates the concrete; Therefore, the study of the diffusion distribution of chloride ions in concrete can objectively predict the service life of concrete.