Influence of Cow Bone Powder on Selected Engineering Properties of Lime-Stabilized Soil

Abstract

This study investigates the influence of cow bone powder (CBP) on consistency and compaction characteristics of lime-stabilized soil. Twelve soil samples were collected from four routes connecting Ado-Ekiti. Index and compaction tests were performed on the natural and stabilized samples. The soil samples were classified according to AASHTO groups and eventually restructured into four (4) groups: A-6, A-7-6, A-4, and A-7-5. They were named samples A, B, C, and D respectively. The oxide compositions of the samples were determined. Lime was blended with soils at proportions of 0, 2, 4, 6, 8,10 %, and the optimal lime content (LimeOpt) was obtained. The LimeOpt + soil mixture was mixed with 2, 4, 6, 8,10 % of CBP. The Soil + LimeOpt + CBP mixtures were subjected to consistency limits and compaction tests. Plasticity index (PI) of soils A, B, C, and D was 14.19, 21.06, 11.64, and 14.19 % respectively, while the MDD was 1640, 1730, 1630, and 1631 kg/m3. Soil A, B, C, and D + LimeOpt all had reduced PIs of 7.68, 16.40, 5.04, and 12.05%, respectively. For the MDD of soil + LimeOpt mixtures, 1789, 1920, 1906, and 1898 kg/m3 were also found for Samples A, B, C, and D. Soil + LimeOpt + CBP showed that both the PI (from 0.6 to 81.7%) and MDD (from 0.1 to 14.6%) improved. On the other hand, the addition of lime to soils A, B, C, and D showed that 8% lime content offered the optimal CBR performance. Further addition of CBP to the soil + LimeOpt mixtures equally improved both the soaked and unsoaked CBR of soils A, B, C, and D predominantly with 6% CBP addition offering the peak performance. This suggests that CBP is viable and can save cost, mitigate environmental hazards, and complement lime. Strength and durability evaluation of the ternary mixture is however recommended.