Impact of wetting–drying cycles on swelling behavior of clayey soils modified by silica fume

Expansive clayey soils contain silicate clay minerals that have the potential for swelling and shrinkage under changing moisture contents. Cyclic wetting–drying phenomena can cause progressive deformation of expansive clayey soils, which may affect building foundations, drainage channels, and liner and cover systems in waste containment facilities. To reduce the effects of cyclic wetting–drying phenomena, it is essential to modify these soils by stabilization techniques. For this purpose, expansive clayey soil samples have been modified using silica fume waste material and the effects of wetting and drying cycles on swelling behavior of modified expansive clayey soils have been investigated under laboratory conditions. A natural clayey soil and clayey soil–silica fume mixtures have been compacted at the optimum moisture content and all samples have been subjected to cyclic wetting–drying and swelling tests. The results show that silica fume decreases the progressive deformation of modified expansive clayey soils subjected to cyclic drying and wetting.