洞库混凝土结构冷凝结露机理与耐久性对策

Cold Condensation Dew Mechanism and Durability Countermeasures of Concrete Structures in Caverns

文章分析了洞库内洞壁结露导致混凝土结构腐蚀机理,实测了洞库内外一日温湿度环境变化,讨论了洞库洞口风速、通风条件对洞库结露的影响,以及外界大气温度、洞库内空气温湿度以及洞壁温度的变化规律。研究表明,洞库内部温度低于露点温度是必然会出现的物理现象,无人干燥封洞、有人温湿控制、设置除湿系统等应对冷凝结露的措施是提高洞库混凝土结构耐久性有效途径。

Moisture condensation often occurs in the cave wall in service, which will result in the deterioration of the small environment inside the cave, accelerate the corrosion of materials and equipment, reduce the reliability of equipment and lower the durability of the concrete structure of the cave. In this paper, the mechanism of concrete structure corrosion caused by condensation of cave wall is analyzed. The changes of daily temperature and humidity environment inside and outside the cave are measured. The influence of wind speed and tunnel ventilation on tunnel temperature field distribution is discussed. Then, the change rules of ambient air temperature, air temperature and humidity in the cave and the temperature of tunnel wall are summarized. The research shows that it is an inevitable physical phenomenon that the internal temperature of caverns is lower than the dew point temperature, and measures to deal with cold condensation dew, such as unmanned drying and sealing, temperature and humidity control and dehumidification system, are effective ways to improve the durability of concrete structures in caverns.