Kaolin soil and its stabilization potentials as nanostructured cementitious admixture for geotechnics purposes

Abstract

The use of nanostructured kaolin as an additive in the stabilization of lateritic soils and its effect at different percentages on the natural soil were investigated. A UV–vis spectrophotometric characterization was conducted to determine the absorbance and average particle size of the nanostructured kaolin. The preliminary tests on the soil showed that it was a poorly graded (GP) soil on USCS. The soil sample was also observed to be silty clayey sand. The consistency limits result showed a liquid limit (LL) of 47% and plastic limit (PL) of 25.15%. The soil was observed to be highly plastic, of high swelling potential and medium expansion properties. Further, the effect of the addition of Nanostructured kaolin (NK) in the proportions of 3%, 6%, 9%, 12% and 15% by weight of the treated lateritic soil recorded the following results; the consistency limits results showed that the addition of variable proportions of nanostructured kaolin (NK) improved the plasticity index of the stabilized soil and gave 11.77%-a medium plastic material at 15% NK by weight addition compared to the preliminary result at 0% by weight additive which gave 21.85%-a highly plastic material. The strength properties test also showed significant improvements with the addition of NK; CBR test results recorded 23% at 15% by weight proportion of NK, which satisfies the material condition for use as a sub-base material and the UCS test results similarly improved consistently and recorded a maximum of 340.18 kN/m2 at 15% by weight proportion of NK addition, which satisfies “very stiff” material consistency for use as a sub-base material. With the foregoing, NK has shown to be a good admixture material for soil stabilization towards solving the myriad pavement and environmental failures and problems with our road pavements.