EFFECT OF MICROSILICA ON THE SWELLING CHARACTERISTICS OF EXPANSIVE SOILS WITH AND WITHOUT LIME

Abstract

The chemical additives are one of the most common solutions to stabilize expansive clay. Microsilica is one of these additives used recently to improve the engineering properties of soft and plastic clay. This study investigates the suitability of such additive to improve the swelling characteristics. Moreover, two cases will be examined; the effect of adding (0 - 10) percentages of the microsilica alone and the microsilica in conjunction with lime. The results indicate that, the microsilica has a positive effect on the swelling characteristics especially in the presence of lime. The percent of free swell and swell pressure decreased 24.49% and 34.64% respectively due to adding up to 10% of microsilica. This reduction becomes 53.94% for free swell and 59.75% for swell pressure when added in the presence of 2% of lime. Moreover, approximately 85% of this reduction has been achieved at 4 % of microsilica and 2 % of lime.