Permeability of Cement-Rice Husk Ash Treated Lateritic Soil

Abstract

A-7-6 lateritic soil was treated at British Standard Light (BSL) compaction energy with up to 8% cement (by dry weight of the soil) at 2% variation and each was admixed with up to 8% Rice Husk Ash (RHA) at 2% variation. Effects of the ash on the soil-cement mixtures were investigated with respect to Maximum Dry Density (MDD), Optimum Moisture Content (OMC) and coefficient of permeability. The MDD of the soil-cement specimens decreased with increasing RHA content at specified cement contents to their minimum values at 6% RHA. The OMC of the specimens increased with increasing percentages of the ash. The coefficient of permeability of the cured specimens decreased with increase in the ash content to their minimum values at 4% RHA content, and beyond this point, there was no further significant reduction in the permeability. These results indicate that not more than 4% RHA can be used with cement to reduce the permeability of lateritic soils.