分析了干湿交替过程中混凝土内湿分布状态变化的机理,建立了海洋潮汐模拟试验系统,并利用该系统研究了海工混凝土中湿分布随高程的变化规律.研究结果表明:海洋环境中不同区位混凝土的湿传输影响深度和稳定湿含量不同;处于稳定海洋大气环境中的混凝土,其内外的湿含量分布较为均匀,湿传输影响深度为0,稳定湿含量为平衡湿含量;在浸泡区,湿传输影响深度为0,稳定湿含量等于饱和湿含量;在干湿循环的浪溅区,存在一定的湿传输影响深度,内部的稳定湿含量等于与大气相平衡的湿含量;在干湿循环的潮差区,稳定湿含量介于饱和湿含量和平衡湿含量之间且随高程的增大而降低,湿传输影响深度随着高程的增长而增大且在浪溅区和潮差区的交界处(潮差区的高潮位)达到最大,该部位水分向混凝土内的传输速率最快,是混凝土结构耐久性设计和维护的关键部位.
In this paper, the variation mechanism of moisture distribution in concrete during the drying-wetting cycle was analyzed, and an experiment system for the marine environment simulation was constructed and is used to investigate the variation of moisture distribution in different zones of marine concrete along the elevated altitude. The results show that the moisture transport-influenc zones of concrete, that the moisture content distribu ng depth and the stable moisture content are dependent on the ion in concrete in stable marine atmosphere environment is re- latively uniform, with a moisture transport-influencing depth of 0 and a corresponding stable moisture content equa- ling the equilibrium value, that the moisture transport-influencing depth of the concrete fully submerged in water is also zero but the corresponding stable moisture content is equal to the saturation value, that there is a spatial distri- bution of the moisture transport-influencing depth of the splash zone subjected to cyclic drying and wetting, with a stable moisture content of the concrete equaling the ambient equilibrium value, and that, in the tidal zone subjected to cyclic drying and wetting, the stable moisture content varies between the saturation and the equilibrium moisture contents and increases inversely with the elevation, while the moisture transport-influencing depth increases posi- tively with the elevation and reaches its peak value in the boundary of the splash and the tidal zones, namely the top water line of tidal zone, which means that the top water line is the key region of durability design and maintenance of concrete structures because moisture transports to the concrete with the highest speed in this region.