Effect of metakaolin on the mechanical properties of lateritic soil

Abstract

The effect of varying additions of metakaolin (MK) on the mechanical properties of lateritic soil to be utilised in the construction of pavement foundations was studied. The preliminary test results show that the soil is highly plastic and lacks sufficient mechanical ability to be used as a compacted subgrade/sub-base for flexible pavement foundation. Kaolin was calcinated to form MK, which was utilised at proportions of 3, 6, 9 and 12% by weight of the dry lateritic soil to stabilise it. California bearing ratio (CBR) and unconfined compressive strength (UCS) tests were conducted on the MK-treated lateritic soil to determine the suitability of the treated materials in the construction of compacted subgrade and/or sub-base layers of flexible pavement. The stabilisation test results show that MK has the potential to be utilised to improve the CBR and UCS of lateritic soil with a peak proportion of 6% MK by weight of dry soil, beyond which the soil experiences a decline in strength formation.