The Effect of Tincal Additive on the Consolidation and Shear Strength Behavior of Sand-Bentonite Mixtures Under High Temperature

The importance of thermal behavior of soils has increased considerably in the last decades. The reason for this, soil properties are temperature-dependent and they are significantly affected by high temperatures and thermal cycles. Previous studies indicate that properties of soils such as shear strength, compressibility, and permeability change at high temperatures. High thermal resistance and durable soils are needed for structures where the soil is exposed to heat such as nuclear waste disposal facilities, buried high voltage cables, energy piles, etc. Boron reduces heat expansion of the glasses, protects the glass against acid and scratches, and also is known with its resistance to high temperature. In this study, the settlement and shear strength properties of sand-bentonite mixtures were determined in the presence of boron mineral; namely tincal under high temperature. The sand-bentonite mixtures were prepared with 10 and 20% bentonite and then 10, 20% tincal were added to these mixtures. The direct shear tests were conducted on all mixtures under 80 °C and room temperature. According to the test results, cohesion value increased in the presence of tincal at room temperature. Furthermore, the internal friction angle values at 80 °C are higher than at room temperature in the presence of tincal. The results have shown that the shear strength of sand-bentonite mixtures increased with tincal additive under high temperature.