Interactions between concrete and brine at the Waste Isolation Pilot Plant (WIPP) Site, New Mexico
- Sandia National Labs., Albuquerque, NM (United States)
- Army Engineer Waterways Experiment Station, Vicksburg, MS (United States). Structures Lab.
A concrete liner emplaced in 1984 in a shaft at the Waste Isolation Pilot Plant has served as a natural laboratory for observing interactions among concrete, evaporite rocks, and brine. During a routine inspection of the liner in the spring of 1990, discoloration, deposition of secondary salts, wet areas with exposed aggregate grains, softening of paste, surficial spalling, and cracking were observed locally on the concrete surface of the liner. Some construction joints showed apparent leakage of brine from behind the liner, which was nominally 50 cm thick. Seepage brines were nearly saturated relative to CaCl{sub 2} and contained lesser amounts of MgCl{sub 2} and KCl, and minor NaCl. The liner surface was locally altered to a 1--2 cm friable hygroscopic layer containing little cement paste; concrete cores (7 or 10 cm diameter) through the liner at depths of 248, 254, 255, and 271 m showed similar degrees of alteration at the liner/rock interface. The most profound alteration of concrete was developed in a {approximately}7 cm zone subparallel to and straddling the construction joint cored at a depth of {approximately}254.5 m. This zone was extensively microfractured, transected aggregate grains, and contained brucite, gypsum, magnesium hydroxychloride hydrate, and locally calcium chloroaluminate instead of the usual phases of hydrated portland cement. Several mechanisms of chemical degradation have been proposed, the most likely being attack by magnesium ions.
- Research Organization:
- Sandia National Labs., Albuquerque, NM (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-76DP00789
- OSTI ID:
- 10113974
- Report Number(s):
- SAND-91-1421C; CONF-911202-30; ON: DE92005458
- Resource Relation:
- Conference: Annual fall meeting of the Materials Research Society (MRS),Boston, MA (United States),2-6 Dec 1991; Other Information: PBD: [1991]
- Country of Publication:
- United States
- Language:
- English
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Interactions between concrete and brine at the Waste Isolation Pilot Plant (WIPP) Site, New Mexico
Interactions between concrete and brine at the Waste Isolation Pilot Plant (WIPP) Site, New Mexico