Effect of Nano and Ordinary Particles of Silica on the Swelling Properties of Expansive Soil

Soil improvement is one of the techniques used to reduce the swelling behavior of expansive soil. In this study, highly expansive soil obtained from the site of the new branch of Al-Azhar University in Al-Kawthar city, Sohag government, at a depth of 2.5 m, was used to make a comparison study on the effect of using nano-silica and three different types of granule sand (medium sand, fine sand, and micro sand) on the swelling properties of expansive soil. The swelling properties tests and consistency limits tests for expansive natural soil and swelling soil mixed with 10%, 15%, and 20% of medium, fine, and micro sand and 1%, 1.5%, and 2% of nano-silica were conducted under laboratory conditions. The main results showed that adding nano-silica and ordinary silica particles to expansive soil caused a significant decrease in swelling properties and Atterberg limits. Nano-silica played an important role in improving the swelling behavior of expansive soil.