Evaluation of strength properties of clay treated by nano-SiO₂ subjected to freeze–thaw cycles

Abstract

Stabilisation by nanoparticles can be considered as an efficient method for enhancing the mechanical properties of clay exposed to the freeze–thaw cycles. The laboratory tests were conducted to understand the effects of various freeze–thaw cycles on clay treated with different percentages of nano-SiO₂. In this paper, unconfined compressive strength (UCS) and shear resistance of soil, as well as the influencing mechanism of nano-SiO₂ was evaluated.The results showed that nano-SiO₂ leads to improve and prevent the resistance reduction of clay due to the freeze and thaw processes. After 9 cycles, the UCS and shear strength of clay treated with 1.0% nano-SiO₂ were 16% and 21% more than natural clay which was not subjected to the freeze–thaw cycles. Scanning electron microscopy (SEM) images represent that nano-SiO₂ produces whiskers under thermal stresses caused by freeze–thaw cycles. The whisker phenomenon leads to a significant increase in the mechanical properties of clay by creating filamentary networks.

KEYWORDS:

• Freeze–thaw cycles
• nano-SiO₂
• mechanical properties
• whiskers
• clay

Acknowledgments

The research presented in this paper was supported by Ziggurat Company in Iran. This experimental research was conducted in the Soil Mechanical Laboratory of Tadbir Sazeh Ziggurat Consulting Company. The authors appreciate the head of Ziggurat Company, Mr. Essam Ghayyem for his cooperation in this research.

Disclosure statement

No potential conflict of interest was reported by the authors.

Correction Statement

This article has been republished with minor changes. These changes do not impact the academic content of the article.