CIEMAT Publications

Abstract

A bentonite column consisting of two parts (a compacted block at the bottom and a mixture of pellets and powder on top) was placed in an instrumented cell and saturated under constant volume conditions. The water intake, development of radial pressure and relative humidity evolution were followed. When the test was dismantled the column was subsampled to determine the final physical state and microstructural characteristics of the bentonite. The results are compared with those of a twin test differing only in the disposition of block and mixture inside the cell. The analysis shows that the microstructure of the two materials tends to homogenise, and that the performance of two-component buffers during hydration is optimal and essentially similar to that of a one-component buffer.