Thermodynamic equilibria-based modelling of reactive chloride transport in blended cementitious materials
Cherif, R.; Hamami, A.E.A.; Ait-Mokhtar, A.; Bosschaerts, W. (2022). Thermodynamic equilibria-based modelling of reactive chloride transport in blended cementitious materials. Cement and Concrete Research 156: 106770. https://dx.doi.org/10.1016/j.cemconres.2022.106770
In: Cement and Concrete Research. PERGAMON-ELSEVIER SCIENCE LTD: Oxford. ISSN 0008-8846; e-ISSN 1873-3948, more
|  |
| Author keywords |
Transport modelling; Durability; Chlorides; Dissolution; precipitation rates; Scanning electron microscopy |
| Authors | | Top |
- Cherif, R.
- Hamami, A.E.A.
- Ait-Mokhtar, A.
- Bosschaerts, W., more
|
|
|
| Abstract |
A physico-chemical modelling of multispecies transport through cementitious materials is proposed considering thermodynamic equilibria, diffusion and migration. The model considers seven species profiles (Cl−, Na+, K+, Ca2+, SO42−, Al(OH)4− and OH−) and the dissolution/precipitation rates during multispecies transport under an electrical field. The fluxes are calculated by the Nernst-Planck equation. Case studies were performed simulating the chloride migration test in the steady state and NT Build 492 test on cement pastes based on slag and/or Portland cement. In order to simulate real exposure to seawater, the migration tests were based on synthetic seawater in the upstream compartment and a synthetic pore solution in the downstream. Pore solution extractions and scanning electron microscopy were performed in order to provide input data and to monitor dissolution/precipitation reactions. The proposed modelling highlights a reduction of up to 10% of free chlorides in the material tested compared to the classic Nernst-Planck modelling. |
|
