Changes in Hydraulic Conductivity of Compacted Lateritic Soil in Response to Ceramic Dust Treatment

Abstract

This study investigates the potential of using up to 12% ceramic dust (CD) to improve the hydraulic conductivity of compacted lateritic soil for landfill liner application. To achieve this objective, the following tests; natural moisture content, Atterberg limits, specific gravity and sieve analysis, compaction as well as hydraulic conductivity tests were conducted, compaction test was carried out using three energy levels namely: British Standard Light (BSL), West African Standard (WAS) i.e. “Intermediate effort” and British Standard Heavy (BSH) efforts. Hydraulic conductivity tests were carried out under dry of optimum, optimum and wet of optimum compaction conditions. The results obtained shows that the soil is classified according to American Association of State Highway and Transport Officials (AASHTO) as A-2-6 and OL by Unified Soil Classification System (USCS).Test results indicate that liquid limit (LL) ranged from 54.0 to 54.2%, Plastic limit (PL) from33.18 to 41.89% and Plasticity index (PI) from 2.31% to 20.82% for CD content adopted in this study. The compaction test results shows that MDD is in the range of 1.29kg/cm3to 1.67kg/cm3, with corresponding OMC which decreased from 24 to 16%.The hydraulic conductivity result decreased from 1.49 x 10-8m/s to 8.143x10-10 m/s for CD content of 0 – 6%. Clay liners in landfills are expected to have a hydraulic conductivity of1x10-9 m/sec. or less. Consequently, only mixture with 6% treatment corresponding to 1.67kg/cm3 MDD met the requirement (i.e. ≤1 x 10-9 m/s)for construction of liner and cover systems for MSW containment.