Wet-dry cycle of expansive soil stabilized with fly ash and waste foundry sand on bearing capacity and swelling potential

Abstract

The behavior of expansive soil, which is sensitive to water, makes it susceptible to moisture content changes, resulting in the soil becoming soft during the rainy season and soil shrinkage during the dry season. This research aims to study the effects of the wet-dry cycle on the bearing capacity and swelling potential of stabilized expansive clay soil using two types of industrial waste, namely Fly Ash (FA) and Waste Foundry Sand (WFS), as soil improvement and industrial waste management efforts. The wet-dry cycle is assumed to represent the changes in the environment due to seasonal variations. The wetting cycle is conducted by immersing the soil samples in water, while the drying cycle is achieved by allowing them to air dry at room temperature. The FA content is set at 9% and the WFS content at 15% by weight of dry soil. The California Bearing Ratio (CBR) test is performed after the completion of the wet-dry cycle, while the swelling test is conducted during the wet-dry cycle. Each sample undergoes one, two, and three cycles of wetting and drying. The results showed that the CBR value increased with the addition of FA and WFS. The CBR value of natural soil is 8.89% while the CBR value of soil+9%FA+15%WFS is 16.02%. During the wetting phase, the CBR value decreases with increasing moisture content. After undergoing the third cycle, the CBR value and development potential tend to remain constant.