Moisture changes in swelling clays are associated with corresponding volume changes, causing these soils to swell upon wetting and shrink upon drying. These volume changes cause subsidence, heave, and crack formation. It is becoming increasingly clear that the engineering and agronomic use of such soils requires special care. Present methods of determining soil volume changes have many constraints. They require the use of hazardous chemicals, take a long time to complete, are not useful near the wet end of the moisture range, and have limited accuracy. A new method of soil volumetric shrinkage measurements using a balloon apparatus is presented. In this method, the soil bulk volume is determined by measuring the displacement of the soil specimen in water with the soil specimen wrapped in a flexible rubber membrane, an ordinary rubber balloon. The method is very simple and doesn't require use of any chemicals. Therefore, it is environmentally safer than other methods. The volumetric shrinkage measurements can be completed for the full moisture range in a short time. The proposed method compares very favorably with the results of the resin coating method.
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Tariq et al. (1993) studied this question.