Effects of Kaolin and Sodium Hydroxide on the Geotechnical Properties of Lateritic Soil
1*Oluremi, J.R., 2Yusuf, A.L., 3Bamidele, O.A. and 4Osuolale, O.M.
1,2,3,4Department of Civil Engineering, Ladoke Akintola University of Technology, Ogbomoso, Oyo State.
DOI: 10.36108/laujoces/6202.71.0132
Abstract
Lateritic soils in tropical regions often exhibit high plasticity and moisture sensitivity that compromise pavement performance, even where bearing capacity is otherwise adequate. This study investigated the stabilization of lateritic soil using varying proportions of kaolin (0, 7.5, 15 and 22.5%) and sodium hydroxide, NaOH (0, 0.5, 1.0 and 1.5%) across 16 treatment combinations. Material characterization by X-ray fluorescence (XRF) and X-ray diffraction (XRD) confirmed both soil and kaolin as aluminosilicate materials, Atterberg limits, compaction, and California Bearing Ratio (CBR) tests, were used to evaluate the performance of the stabilized lateritic soil,. The use of Kaolin or NaOH alone produced inconsistent CBR relative to untreated soil, but combined treatment led to improved workability and CBR of the stabilized material at 15% kaolin with 1.5% NaOH, and 7.5% kaolin with 1.0% NaOH, respectively. The admixture of kaolin-NaOH is proved to be a potential stabilizing system for lateritic subgrade improvement, but warrant further validation through replicated trials and comparison with conventional stabilizers.
Keywords: Lateritic soil; Kaolin; Sodium hydroxide; Alkali activation; Soil stabilization; California Bearing Ratio