The solution, based on Neumann's theory, for the content distribution of a diffusion material in a semi-infinite medium is applicable for the case in which a diffusion material diffuses from one side of a plate medium to the other side. After the diffusion material reaches the other side, the penetration rate of the diffusion material is solved using Fick's diffusion law. In this study, concrete plates are manufactured and submerged individually in special containers with saltwater on one side and freshwater on the other side, and no electric charge is applied. The amount of chloride penetrating the plate is monitored. Data are used to derive the diffusivity and Neumann’s constant, which are used to characterize penetration lag and rate. The value of Neumann's constant is derived for the first time. This advancing model for a plate-shaped medium is also novel, and makes calculation of the penetration lag and diffusion depth possible.
Wang, Chih-Hsing; Tsai, Cho-Liang; and Lin, Ching-Chang
"PENETRATION LAG OF CHLORIDE DIFFUSION THROUGH CONCRETE PLATE BASED ON ADVANCING MODEL,"
Journal of Marine Science and Technology: Vol. 19
, Article 5.
Available at: https://jmstt.ntou.edu.tw/journal/vol19/iss2/5