Investigation of The Use of Rise Husk Ash-Lime to Stabilize Low Plasticity
Laterite soil is a locally available material used in construction and because of its properties, it requires stabilisation when used in block making since the blocks are always subjected to structural loads whenever used in building of structures. Stabilised interlocking blocks have been produced widely in Uganda while employing cement stabilisation however Cement its self is criticised to be expensive and it leads to increased Carbon dioxide emissions in the atmosphere. Experiments done about this research aim at incorporating RHA-Lime in the stabilisation of laterite soil for making interlocking compressed earth blocks so as to improve the geotechnical properties of the soil that would have been improved by cement. In these experiments, interlocking compressed earth blocks were cast using 5% of cement (control) and 4% Lime with varying RHA percentages of 0%, 2%, 4%, 6%, 8% and 10%. The compressive strength and water absorption rate tests were carried out on the blocks at 14, 21 and 28 days of curing. According to the results obtained, the optimum proportion was achieved with blocks cast using 4% lime with 6% RHA which gave the maximum compressive strength of 4.20 N/mm2, 7.83 N/mm2 and 8.73 N/mm2 with a minimum water absorption rate of 9.6%, 9.0% and 8.5% at 14, 21 and 28 days of curing. It was therefore concluded that the blocks made using RHA-Lime met the required standards as recommended by Uganda bureau of Standards with less carbon dioxide emissions hence they can be employed in the construction company.
Keywords: Laterite soils, Stabilisation, Interlocking compressed earth blocks, cement, Lime, Rice Husk Ash.