Evaluation of Cow Bone Ash (CBA) as Additives in Stabilization of Lateritic and Termitaria Soil

Abstract

Continual pavement distresses on Nigerian highways, as well as environmental contamination from abattoir solid wastes such cow-bones have been a major concern. This study examined the usage of additives in stabilizing weak soils and enhancing their geotechnical properties utilizing Cow Bone Ash (CBA) on lateritic and termitaria soils. The following engineering confirmatory tests were carried out on the samples: compaction test, unconfined compressive strength (UCS) and California bearing ratio (CBR) test. CBA at 2%, 4%, 6%, 8%, and 10% were added to the soil samples. The study revealed that for lateritic and termitaria soils, the maximum amount of CBA that would allow for an increase in soaked CBR value was at 6% and 8%, respectively, while for the unsoaked CBR, the peak values was obtained at 8%. Also, the addition of CBA increased the UCS of both soil samples. The addition of CBA resulted in decreasing optimum moisture content (OMC) for termitaria soils as its pore spaces are filled up by the CBA while for the lateritic soils, increase in CBA resulted in increased OMC values. Also, the addition of CBA to both soil samples resulted in an increase in maximum dry density (MDD) values. The study revealed that termitaria soils have higher strength than the lateritic soils due to higher cohesiveness within its pore structure, lower OMC, higher MDD, UCS, and CBR values. The study concludes that the use of CBA to a maximum of 8% as an additive in stabilization of lateritic and termitaria soils is effective and therefore recommends its use in light and medium trafficked roads.