Accession Number : ADA190504

Title :   Studies of the Geochemical Stability of a Salt-Saturated Expansive Grout.

Descriptive Note : Final rept. Oct 86-Jun 87,

Corporate Author : ARMY ENGINEER WATERWAYS EXPERIMENT STATION VICKSBURG MS STRUCTURES LAB

Personal Author(s) : Wakeley, Lillian D ; Poole, Toy S

PDF Url : ADA190504

Report Date : Sep 1987

Pagination or Media Count : 80

Abstract : Laboratory experiments were conducted on several aspects of durability of grout in the special environment of a repository for radioactive wastes in bedded halite rock. Variables tested include solubility of grout components, phase changes, and mobility of chloride relative to interfaces with rock and brine or freshwater. The grout tested had large percentages of both chloride and sulfate. Chloride was more mobile when the grout was exposed to freshwater, and sulfate when exposed to brine. Removal of chloride from the grout accompanied loss of chloroaluminate phase, rather than simply dissolution of sodium chloride. However, chloride gradients were not apparently related to an interface between grout and halite rock. With extended exposure to brine or freshwater, calcium represented the largest fraction of mass loss, as determined by analyses of exposure solutions. Sulfate loss was the second largest. This effect increased with time and temperature of exposure. Volume increase of test specimens indicated continued or renewed expansion, even after the initial curing or storage period (28 days or 9 months), when the grout was exposed to water or brine. The combination of volume increase with mass loss suggests a density decrease, but this did not cause loss of physical integrity of specimens. Keywords: Atomic absorption; Ettringite; Chloroaluminate; Expansive cement; Energy-dispersive X-ray analysis(EDX); Expansive grout.

Descriptors :   *GEOCHEMISTRY, *GROUT, *RADIOACTIVE WASTES, *CONCRETE, ABSORPTION, ATOMIC PROPERTIES, BRINES, CALCIUM, CEMENTS, CHLORIDES, LABORATORY TESTS, PHYSICAL PROPERTIES, ROCK, ROCK SALT, SODIUM CHLORIDE, SOLUBILITY, STABILITY, WATER, CANISTERS, TABLES(DATA)

Subject Categories : Geology, Geochemistry and Mineralogy
      Ceramics, Refractories and Glass

Distribution Statement : APPROVED FOR PUBLIC RELEASE