Analysis of Consolidation of Granulated Rocksalt Using a Plastic Flow Model of Isostatic Hot-Pressing

摘要

Since waste repositories sited in naturally occurring salt formations are likely to use crushed rocksalt as backfill to encapsulate waste packages, it becomes necessary that we understand the behavior of this material in order to predict densification rates. The problem of consolidation of powdered aggregates using heat and pressure is an old one in the fields of ceramics and powder metallurgy, and an extensive body of literature exists on the theory and practice of hot-pressing. This report shows that a simple model for hot-pressing fits the results for individual creep consolidation tests reasonably well. This leads us to believe that hot-pressing models are appropriate to the problem in the laboratory. The particular model used predicts an endpoint density beyond which no further densification will occur. However, the current database is insufficient to fully justify either adoption of the model or long-term extrapolation of material response. Further laboratory testing is required to better define the model parameters as functions of temperature, applied pressure, and time. (ERA citation 10:015783)