Modification of Fick''s Diffusion Modelfor Chloride Diffusing in Concrete

• Main Authors: Mei-Yi Yeh, 葉美怡
• Other Authors: Cho-liang Tsai
• Format: Others
• Language: zh-TW
• Published: 2007
• Online Access: http://ndltd.ncl.edu.tw/handle/16060214477315194356

碩士 === 國立雲林科技大學 === 營建工程系碩士班 === 95 === Fick''s diffusion law is usually used in solving diffusion problem. However, a serious problem always involves in the solution solved based on the boundary saturated conditions, which is no mater how deep the location is or how short the diffusion duration is the content of the diffusion substance in the medium is always no zero. The molecule of the diffusion substance needs time to travel in the medium to reach the deep core of the medium. It is impossible for any molecule to appear at the deep inside of the medium in no time. Advancing boundary diffusion model is developed for study the chloride diffusion depth and the chloride content distribution in a concrete plate. In this study, Fick''s diffusion law was applied and an advancing diffusion boundary condition was assumed for a one-dimensional diffusion case where chloride in water diffuses from one side of a water-logged concrete plate to the fresh water on the other side. The diffusion depth and content distribution of the chloride were calculated. The amount of chloride penetrates the concrete was quantified and verified experimentally to confirm the validity of the developed model.