Physico-chemical investigation of clayey/cement-based materials interaction in the context of geological waste disposal: Experimental approach and results

Journal Article · Sun Aug 15 04:00:00 EDT 2010 · Cement and Concrete Research

DOI:https://doi.org/10.1016/j.cemconres.2010.03.015· OSTI ID:21418101

Dauzeres, A ^[1]; Le Bescop, P ^[1]; Sardini, P ^[2]; Cau Dit Coumes, C ^[3]

---

1. CEA Saclay, DEN, DANS, DPC, SCCME, Laboratoire d'Etude des Betons et des Argiles, bat. 158, 91191 Gif sur Yvette (France)
2. Laboratoire HYDRASA FRE 3114 Universite de Poitiers, bat. sciences naturelles, 86000 Poitiers (France)
3. CEA Marcoule, DEN, DTCD, SPDE, Laboratoire d'Etude de l'Enrobage des Dechets, bat. 438, 30207 Bagnols-sur-Ceze (France)

Within the concepts under study for the geological disposal of intermediate-level long-lived waste, cement-based materials are considered as candidate materials. The clayey surrounding rock and the cement-based material being considered differ greatly in their porewater composition. Experiments are conducted on the diffusion of solutes constituting those porewaters in a confined clay/cement composite system using cells. The test temperature was set at 25 {sup o}C and 2, 6 and 12 months. Results supply new information: carbonation is low and not clog the interface. Such absence of carbonation allows for the diffusion of aqueous species and, thus, for the degradation of the cement paste and the illitisation of illite/smectite interstratifications. The cement material is subjected to a decalcification: portlandite dissolution and a CaO/SiO{sub 2} reduction in the calcium silicate hydrate. The sulphate in diffusion induces non-destructive ettringite precipitation in the largest pores. After 12 months, about 800 {mu}m of cement material is concerned by decalcification.

• OSTI ID: 21418101
• Journal Information: Cement and Concrete Research, Journal Name: Cement and Concrete Research Journal Issue: 8 Vol. 40; ISSN 0008-8846; ISSN CCNRAI
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALKALINE EARTH METAL COMPOUNDS
BUILDING MATERIALS
CALCIUM COMPOUNDS
CALCIUM OXIDES
CALCIUM SILICATES
CEMENTS
CHALCOGENIDES
CHEMICAL REACTIONS
CLAYS
DIFFUSION
DISSOLUTION
HYDRATES
ILLITE
INTERACTIONS
INTERMEDIATE-LEVEL RADIOACTIVE WASTES
MANAGEMENT
MATERIALS
MINERALS
OXIDES
OXYGEN COMPOUNDS
PRECIPITATION
RADIOACTIVE MATERIALS
RADIOACTIVE WASTE DISPOSAL
RADIOACTIVE WASTE MANAGEMENT
RADIOACTIVE WASTES
REDUCTION
ROCKS
SEPARATION PROCESSES
SILICATE MINERALS
SILICATES
SILICON COMPOUNDS
SILICON OXIDES
SMECTITE
SULFATES
SULFUR COMPOUNDS
TEMPERATURE RANGE
TEMPERATURE RANGE 0273-0400 K
WASTE DISPOSAL
WASTE MANAGEMENT
WASTES