comparative assessment of rice husk ash, powdered glass and cement as lateritic soil stabilizers

This paper compares the stabilizing effects of three different materials, namely: rice husk ash, powdered glass, and cement on the properties of lateritic soil. The basic properties of the lateritic soil were first obtained through colour, moisture content determination, specific gravity, particle size distribution and Atterberg limits tests. Each of the stabilizing materials was then mixed with the lateritic soil in varying percentages of 2.5%, 5%, 7.5%, 10%, 12.5% and 15% by weight of the soil. Thereafter, compaction and California bearing ratio (CBR) tests were carried out on the sample mixes to determine the effects of the materials on the lateritic soil. Chemical tests were also carried out on the samples to determine their percentage oxides composition. The compaction test showed that the highest maximum dry densities (MDD) obtained for the mixed samples were 2.32 g/cm3 (at 2.5% cement addition), 2.28g/cm3 (at 5% powdered glass (PG) addition) and 2.18 g/cm3 (at 5% rice husk ash (RHA) addition) with corresponding optimum moisture contents (OMC) of 10.06%, 14.3% and 12.31% respectively. The CBR tests showed that the CBR values increased in all cases as the materials were added with those of the cement and powdered glass giving the highest values and showing close semblance under unsoaked conditions. The chemical test showed that the significant oxides present in the cement, powdered glass and rice husk ash were CaO (53.60%), SiO2 (68.45%) and SiO2 (89.84%) respectively.