STABILIZATION OF SOFT SOIL SUBGRADE LAYERS BY USING LIME-MICRO SILICA FUME MIXTURE

Abstract

ABSTRACT :The engineering properties of soft soil subgrade layer my need to be improved to make such as soil good for construction by using stabilization method. Pavement subgrade stabilization relied on treatment with lime, cement, silica fume, and micro silica fume. The main objective of this research is to investigate the effect of lime-micro silica fume mixture on the soft soil properties. A series of laboratory tests have been implemented to the soft soil samples with (0,3,6,9,12)% lime and(0,6,12,18)% micro silica fume. The results indicate improvement on the soft soil engineering properties. The liquid limit values decrease from53% to 33% with L-MSF 12-0%, plastic limit values increase from 27% to 41% with L-MSF 9-18%, and plasticity index values decrease from 26% to 1.21% with L-MSF 9-6%. The max dry density values decrease from 1.62gm/cm3 to 1.32 gm/cm3 with L-MSF 9-18%, and optimum moisture content increase from 22% to 28.66% with L-MSF 12-0%.The CBR values increase from 3% to 13.5 % with L-MSF 6-18%. This research results conclude that lime and micro silica fume can be used to stabilized soft soil subgrade and improve soil properties to make such soil suitable for engineering projects.