EFFECT OF COMPACTION AT DIFFERENT ENERGY LEVELS ON THE GEOTECHNICAL PROPERTIES OF STABILIZED SOILS

Abstract

This study is aimed at evaluating the influence of compaction (at different energy levels) on the geotechnical properties of stabilized soils. To achieve this, four bulk soil samples (BDL1, BDL2 BDL3 & BDT) consisting of termite reworked soils and residual lateritic soils were collected at New Stadium Road, Awo hall, University of Ibadan, Nigeria at a depth of 2m for strength tests and at depths of 1m, 1.5m & 2m for index tests. Geotechnical analysis (index tests and strength tests) and geochemical analysis (X-ray Diffraction) were carried out on the sampled soils. The study revealed that the mineral constituents of the sampled soils are quartz, kaolinite and hematite; with the termite-reworked soil richer in kaolinite content than the quartz schist derived soil with about 125% increase. The values of index tests for both soils met the required Nigeria specification for good soil with termite reworked soil performing better. The values of specific gravity for both soils are close suggesting similar origin. AASHTO classification put termite-reworked soil within the range of A-2-7 (good rating) while most of the residual soil samples fall within A-7-5 to A-7-6 range (fair to poor rating). The stabilisation of residual lateritic soil using termite-reworked soil as stabiliser brought about increase in the values of maximum dry density, uncured unconfined compressive strength as well as the sun-cured unconfined compressive strength of the studied soil. The influence of stabilisation using termite-reworked soil was strongest at the highest level of compaction ((30%) of termite-reworked soil with the weight of residual soil). There also exist a fairly strong positive correlation between the amount of termite reworked soil and energy of compaction and between the uncured and sun-cured unconfined compressive strength was plotted against the number of blows for BDL1, BDL2 and BDL3 respectively. In sum, these stabilised soils are suitable for foundation and landfills materials.