Swelling Behavior of Sand-Bentonite Mixtures
M. Kuruoglu, G. Boran, O. Elmas
Dokuz Eylul University, Tinaztepe Campus, Izmir, 35390 Turkiye
Keywords: Sand, bentonite, swelling behavior, final void ratio, compactive effort
Abstract
In this study, the swelling behavior of sand-bentonite mixtures and pure bentonite are investigated by considering different factors, such as bentonite content in the mixture, specimen preparation method by applying different compactive efforts, and varying effective stress levels. Compaction tests were performed on the specimens of the sand-bentonite mixtures with 10% and 20% bentonite contents and pure bentonite. The maximum dry unit weight and the optimum water content of the specimens with 20% bentonite were relatively higher than specimens with 10% bentonite. Pure bentonite specimens had a lower maximum dry unit weight and higher optimum water content compared to sand-bentonite mixtures. Specimens of the swelling tests were prepared at the optimum water content values. Up to a vertical effective stress of 25 kPa, the mixtures showed a swelling behavior. Under the effective vertical stresses of 50 and 100 kPa, it was evident that the specimens behaved in the compression side. It was seen that the application of either 10 or 25 blows by means of compactive effort in pure bentonite specimens had a neglectible effect on the swelling behavior.
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