Resistance and Swellability of Stabilized Samples of Marl Problematic Soils Using Nano-silica and Nano-alumina

Abstract

This study investigates the effects of Nano-silica and Nano-alumina on the Marl soil as a problematic soil in Tabriz, Iran. These soils, which are among the swellable soils, constitute the foundation of most projects in Tabriz. Due to water absorption, these soils are liable to volume change and instability risks in the foundation of projects. Consequently, various physical and chemical methods have been employed to stabilize these soils. In the present study, for the first time, the reconstructed samples of Tabriz Marl were stabilized with various percentages of Nano-silica and Nano-alumina, which have fewer environmental effects in comparison with ordinary additives such as Portland cement or lime. In addition, soil swelling behaviors have been evaluated by various experiments including Atterberg limits, density, free swelling, swelling pressure, California Bearing Ratio (CBR) tests, direct shear tests, Field Emission Scanning Electron Microscopy (FESEM), and X-ray powder diffraction (XRD) analyses which were conducted at 1, 7, and 28 days of curing times. The results show that Nano-alumina has a greater effect on reducing the swelling of stabilized samples than Nano-silica. However, the effect of Nano-silica has been more than Nano-alumina on increasing the strength CBR.