It is a very interesting paper [1] and the author should be congratulated for touching such an important subject and making a comprehensive review. However, while doing so the author has discussed many other topics which are not connected with the calculation of chloride difussion coefficient. For t
Calculation of chloride diffusion coefficients in concrete from ionic migration measurements
โ Scribed by C. Andrade
- Publisher
- Elsevier Science
- Year
- 1993
- Tongue
- English
- Weight
- 953 KB
- Volume
- 23
- Category
- Article
- ISSN
- 0008-8846
No coin nor oath required. For personal study only.
โฆ Synopsis
A critical review is offered on the Rapid Chloride Permeability Test standarized by AASHTO, pointing out its limitations and errors but recognizing its contribution to the developing of a simple and quick test for chloride migration.
Then another review is made on the electrochemical fundaments of the processes developped in concrete when an electrical field is applied and on the basic equations of mass transport (Nernst-Plank and Nernst-Einstein) which can be applied to calculate ionic movements. The limitations and assumptions needed for a simplified resolution of these equations, are presented, as well as numerical examples of calculation of the Effective Diffusion Coefficient of chlorides, De~ , in steady state condition. Finally, considerations on the possibility of calculation of Dc~ from simple resistivity measurements are also offered.
๐ SIMILAR VOLUMES
Shortening of the testing time to characterize concrete resistance to chloride penetration was the main practical improvement of the so called "Rapid Chloride Permeability Test" developed by Whiting. Recently, numerous papers were published presenting results using this method already standarized by
Previous model based on free-water properties to interpret the measured diffusion coefficient in compacted bentonite-based materials is demonstrated to be inadequate. A model considering ionic diffusion in clay surface (bound) and interstitial (free) water is presented to interpret the measured diff
## Abstract On the basis of the LPE GaAs growth rate measurements in which we used current marks of time, the diffusion coefficient and the critical supercooling of arsenic in Ga solution by a semiempirical method was determined. Some knowledge of these parameters is indispensable for investigating