Abstract:

In this paper,the variation mechanism of moisture distribution in concrete during the drying-wettingcycle was analyzed,and an experiment system for the marine environment simulation was constructed and is used toinvestigate the variation of moisture distribution in different zones of marine concrete along the elevated altitude.The results show that the moisture transport-influencing depth and the stable moisture content are dependent on thezones of concrete,that the moisture content distribution in concrete in stable marine atmosphere environment is relativelyuniform,with a moisture transport-influencing depth of 0 and a corresponding stable moisture content equalingthe equilibrium value,that the moisture transport-influencing depth of the concrete fully submerged in water isalso zero but the corresponding stable moisture content is equal to the saturation value,that there is a spatial distributionof the moisture transport-influencing depth of the splash zone subjected to cyclic drying and wetting,with astable moisture content of the concrete equaling the ambient equilibrium value,and that,in the tidal zone subjectedto cyclic drying and wetting,the stable moisture content varies between the saturation and the equilibrium moisturecontents and increases inversely with the elevation,while the moisture transport-influencing depth increases positivelywith the elevation and reaches its peak value in the boundary of the splash and the tidal zones,namely the topwater line of tidal zone,which means that the top water line is the key region of durability design and maintenanceof concrete structures because moisture transports to the concrete with the highest speed in this region.

Key words: concrete, marine environment, marine tide simulation, drying-wetting cycle, moisture transport, influencing depth, moisture distribution