Mineralogical Evolution and Expansion of Cement Pastes in a Sulfate-Confined Environment - Mines Paris Accéder directement au contenu
Article Dans Une Revue Minerals Année : 2023

Mineralogical Evolution and Expansion of Cement Pastes in a Sulfate-Confined Environment

Résumé

The geologic disposal of radioactive waste could lead to confined conditions in which cementitious materials impose a moderate alkaline pH, in which the rocks supply sulfate ions at rather low concentrations. In this context, the purpose of this work was to study the degradation of cement pastes under such conditions using a non-renewed 30 mmol/L Na 2 SO 4 solution without pH regulation. Samples were investigated through laboratory testing and numerical modeling. XRD, SEM-EDS, and micro-indentation acquisitions were performed to follow the evolution of chemical, mineralogical, and mechanical properties during the weak external sulfate attack. Reactive transport modeling was performed with the HYTEC code. Based on these results, the Young's moduli of the degraded zones were estimated using analytical homogenization. Decalcification occurred despite the high pH value of the solution and significantly affected the mechanical properties. Macroscopic swelling and cracking were caused by the formation of expansive sulfate minerals after 60 days, despite the low sulfate content of the tank solution. The modeling supported the discussion on the evolution of the mineral fronts (ettringite, portlandite, and gypsum).
Fichier principal
Vignette du fichier
minerals-v13-2023.pdf (3.46 Mo) Télécharger le fichier
Origine : Publication financée par une institution
Licence : CC BY - Paternité

Dates et versions

hal-03981515 , version 1 (09-02-2023)

Licence

Paternité

Identifiants

Citer

Julie Pouya, Mejdi Neji, Laurent de Windt, Frédéric Péralès, Adrien Socié, et al.. Mineralogical Evolution and Expansion of Cement Pastes in a Sulfate-Confined Environment. Minerals, 2023, 13 (1), pp.1. ⟨10.3390/min13010001⟩. ⟨hal-03981515⟩
54 Consultations
72 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More