High Temperature Effect on the Engineering Performance of Pumice Added Sand-Bentonite Mixtures

Abstract

The surrounding soils at energy geo-structures must perform for a long time under high temperatures and thermal cycles. Engineering properties of soils are affected by temperature. Pumice is a thermally durable material and it may be used to increase thermal durability of soils. For this reason, it was aimed to develop thermally durable soil material by adding pumice additive to sand-bentonite mixtures. 10% and 20% pumice were added to 10% and 20% sand-bentonite mixtures and compaction, consolidation, direct shear and hydraulic conductivity tests were performed. The direct shear and hydraulic conductivity tests were performed both at room temperature and 80 °C. The consolidation test results showed that as pumice content increases the total vertical deformation decreased at room temperature. Pumice additive reduced the maximum shear stress values when temperature increased for 10B-90S mixtures. However, the pumice additive increased the internal friction angle of the mixtures at high temperature. It was observed that the hydraulic conductivity increased with increasing temperature. Thermal conductivity measurements showed that pumice additive reduced the thermal conductivity value of the mixtures.