Computational Technology Resources - CCP

J. Nemecek¹ and Y. Xi²

¹Department of Mechanics, Faculty of Civil Engineering, Czech Technical University in Prague, Czech Republic
²Department of Civil, Environmental and Architectural Engineering, University of Colorado, Boulder, United States of America

Keywords: concrete, reinforcement, corrosion, chloride extraction, diffusion, electromigration.

Summary

This paper is focused on simulations of electromigration tests performed to extract chlorides from concrete samples. The paper shows experimental results and the efficiency of the short-term treatment of the samples in low voltage electric field. The method is applied to both accelerated penetration and extraction procedures. The situation is numerically treated as a diffusion-convection problem. An extended Nernst-Planck equation is introduced for which the finite difference method is applied. Using a combination of the difference schemes needs to be used in order to maintain numerical stability of the calculations. The situation is illustrated in the paper along with identification of the diffusion parameters for penetration and extraction. The physico-chemical process of chloride binding in the porous system is quantified in the paper. It is numerically treated using a simplified approach by introducing an apparent diffusion coefficient which is identified from an extraction test by least squares minimization. Its magnitude was found to be one half of the original diffusion coeficient showing a very high degree of binding. The simulation results agree relatively well with the experimental measurements meaning the short term tests can be effectively modeled using the simplified approach.

purchase the full-text of this paper (price £20)

go to the previous paper
go to the next paper
return to the table of contents
return to the book description
purchase this book (price £75 +P&P)

	Computational & Technology Resources an online resource for computational, engineering & technology publications
	not logged in - login
Front Page Browse CCP CSETS CTR IJRT Other Authors Search Purchase Guide FAQ Contact us	Civil-Comp Proceedings ISSN 1759-3433 CCP: 108 PROCEEDINGS OF THE FIFTEENTH INTERNATIONAL CONFERENCE ON CIVIL, STRUCTURAL AND ENVIRONMENTAL ENGINEERING COMPUTING Edited by: J. Kruis, Y. Tsompanakis and B.H.V. Topping Paper 151 Simulation of Chloride Extraction Tests on Concrete Specimens J. Nemecek¹ and Y. Xi² ¹Department of Mechanics, Faculty of Civil Engineering, Czech Technical University in Prague, Czech Republic ²Department of Civil, Environmental and Architectural Engineering, University of Colorado, Boulder, United States of America doi:10.4203/ccp.108.151 purchase the full-text of this paper Full Bibliographic Reference for this paper J. Nemecek, Y. Xi, "Simulation of Chloride Extraction Tests on Concrete Specimens", in J. Kruis, Y. Tsompanakis, B.H.V. Topping, (Editors), "Proceedings of the Fifteenth International Conference on Civil, Structural and Environmental Engineering Computing", Civil-Comp Press, Stirlingshire, UK, Paper 151, 2015. doi:10.4203/ccp.108.151 Keywords: concrete, reinforcement, corrosion, chloride extraction, diffusion, electromigration. Summary This paper is focused on simulations of electromigration tests performed to extract chlorides from concrete samples. The paper shows experimental results and the efficiency of the short-term treatment of the samples in low voltage electric field. The method is applied to both accelerated penetration and extraction procedures. The situation is numerically treated as a diffusion-convection problem. An extended Nernst-Planck equation is introduced for which the finite difference method is applied. Using a combination of the difference schemes needs to be used in order to maintain numerical stability of the calculations. The situation is illustrated in the paper along with identification of the diffusion parameters for penetration and extraction. The physico-chemical process of chloride binding in the porous system is quantified in the paper. It is numerically treated using a simplified approach by introducing an apparent diffusion coefficient which is identified from an extraction test by least squares minimization. Its magnitude was found to be one half of the original diffusion coeficient showing a very high degree of binding. The simulation results agree relatively well with the experimental measurements meaning the short term tests can be effectively modeled using the simplified approach. purchase the full-text of this paper (price £20) go to the previous paper go to the next paper return to the table of contents return to the book description purchase this book (price £75 +P&P)
Back to top	©Civil-Comp Limited 2023 - terms & conditions