Effect of silica fume and curing time on volume change characteristics of rice husk ash stabilized expansive soil

ABSTRACT: This study encompasses an experimental investigation and dissemination of the findings of stabilization of an expansive soil obtained from EMU Campus by using rice husk ash (RHA) and silica fume (SF). The light buildings are continuosly subjected to structural distresses, hence repair and maintenance due to cyclic swelling-drying of the underlying expansive soils induced by climatic wetting and drying. There is a growing interest in utilizing industrial waste mainly for the mitigation of swelling-shrinking soils with a secondary aim of recycling. Within the scope of this study, primarily the stabilization materials were tested for their suitability to be used as pozzolans. After the results of X-ray fluorescence (XRF) and reactivity tests, which indicated that RHA and SF are sufficiently active, they are used in 10% RHA, 15% RHA, 20% SF ve 10% RHA+10% SF proportions by dry mass of the soil. Physical properties and volume change behavior of the natural soil and treated soil were studied. After completing the experimental program which included the swelling-drying, and consolidation without and with curing of 28 days, it was concluded that there has been a notable mitigation mainly in the swelling and shrinkage behavior. Even though this study did not yield very consistent and significant results, it is observed that by increasing the curing time and the amount of additives better results could have been attained. Finally, it was concluded that 10% RHA+10% SF addition has been more effective. Therefore silica fume and rice husk ash together formed the most active combination and is recommended to be mixed and compacted with the expansive soils subject to light loads, such as pavements, roads, and at most two story buildings. Keywords: Expansive soils, Silica Fume, Rice Husk Ash. …………………………………………………………………………………………………………………………………………………………………………………………………………