Title
Numerical model of Ca(OH)2 transport in concrete due to electrical currents
Author
Koster, T.
Peelen, W.
Larbi, J.
de Rooij, M.
Polder, R.
TNO Bouw en Ondergrond
Publication year
2010
Abstract
A mathematical model is being developed to describe a repair method in concrete, called cathodic protection (CP). The model is in principle also useful to describe electrodeposition in concrete, e.g. the process of re-precipitation of Ca(OH)2 invoked by an electrical current. In CP, the current is sent from an external anode to the reinforcement inside the concrete. This model is implemented using the numerical software package Comsol Multiphysics. The model is based on the Nernst-Planck equations and the electroneutrality condition considering the ionic species Na+, OH- and Ca2+ and the solid Ca(OH)2. The mathematical model makes it possible to predict the location where Ca(OH)2 precipitates when a certain current density is used. This could be of great use for controlled crack repair in concrete and for electrochemical re-alkalisation. This paper presents the qualitative behaviour of dissolution and re-precipitation of Ca(OH)2 in CP. It discusses model calculations and preliminary experimental results. Experiments for a more complete validation of the model are in process. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA.
Subject
Building Engineering & Civil Engineering
SR - Structural Reliability
TS - Technical Sciences
Architecture
Crack repairs
Electrical current
Electroneutrality
In-process
Ionic species
Model calculations
Multi-physics
Nernst-Planck equations
Numerical models
Numerical software
Re-precipitation
Repair methods
Calcium
Cathodic protection
Dissolution
Reinforcement
Sodium
Mathematical models
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TNO identifier
408473
ISSN
0947-5117
Source
Materials and Corrosion, 61 (6), 518-523
Document type
article