EVALUATION OF TIME RATE OF SWELLING PRESSURE DEVELOPMENT DUE TO THE PRESENCE OF SULFATE IN CLAYEY SOILS STABILIZED WITH LIME

Abstract

The purpose of this study was evaluation of magnitude and time rate of swelling pressure due
to the presence of gypsum in clayey soils stabilized with lime. 3,5 and 10 % of lime by dry weight and 0, 5
and 10 % of gypsum (calcium sulphate) were added to a bentonite. Then uncured and cured as compacted
samples of mixtures were tested one dimensionally for constant volume swelling pressure measurement. The
results showed that only samples treated with 3 and 5% lime without curing and with 7 days of curing
showed initial increase in the magnitude of swelling pressure due to the presence of gypsum as compared
with untreated bentonite or with bentonite treated with lime only. In fact samples with higher content of lime
and gypsum which cured for 7 days or more actually showed lower swelling pressure compared with
untreated samples.