Accéder directement au contenu Accéder directement à la navigation
Article dans une revue

Modeling the degradation of Portland cement pastes by biogenic organic acids

Abstract : Reactive transport models can be used to assess the long-term performance of cement-based materials subjected to biodegradation. A bioleaching test (with Aspergillus niger fungi) applied to ordinary Portland cement pastes during 15 months is modeled with HYTEC. Modeling indicates that the biogenic organic acids (acetic, butyric, lactic and oxalic) strongly accelerate hydrate dissolution by acidic hydrolysis whilst their complexation of aluminum has an effect on the secondary gel stability only. The deepest degradation front corresponds to portlandite dissolution and decalcification of calcium silicate hydrates. A complex pattern of sulfate phases dissolution and precipitation takes place in an intermediate zone. The outermost degraded zone consists of alumina and silica gels. The modeling accurateness of calcium leaching, pH evolution and degradation thickness is consistently enhanced whilst considering increase of diffusivity in the degraded zones. Precipitation of calcium oxalate is predicted by modeling but was hindered in the bioleaching reactor. © 2010 Elsevier Ltd. All rights reserved.
Liste complète des métadonnées

https://hal-mines-paristech.archives-ouvertes.fr/hal-00557835
Contributeur : Pascale Nalon <>
Soumis le : jeudi 20 janvier 2011 - 11:01:47
Dernière modification le : jeudi 24 septembre 2020 - 16:34:08

Identifiants

Citation

Laurent de Windt, Philippe Devillers. Modeling the degradation of Portland cement pastes by biogenic organic acids. Cement and Concrete Research, Elsevier, 2010, 40 (8), pp.1165-1174. ⟨10.1016/j.cemconres.2010.03.005⟩. ⟨hal-00557835⟩

Partager

Métriques

Consultations de la notice

412