Evaluation of Soil Samples in Abeokuta-South Local Government Area of Ogun State, Southwestern Nigeria

This paper presents result of a laboratory investigation on soil samples from Abeokuta South Local Government, Southwestern Nigeria. Three comparative efforts namely standard Proctor (SP), West African Standard (WAS) and modified Proctor (MP), were employed.  The results obtained showed that the compaction characteristics and unconfined compressive strength of the soil samples were found to increase with comparative effort. The unconfined compressive strength (UCS) values increased with compactive effort and decreased with increase in degree of saturation of the soil samples. All the samples did not meet the minimum specified requirements except for A1, A6 and A8. Upon stabilized with cement, samples A2 and A7 did not also meet the minimum CBR value of 180% as specified by the Nigerian General Specification for roads and bridgeworks (1997) or stabilized soil using standard Proctor compactive effort at 4% cement content. However, all the soil samples met the requirement using WAS compactive effort at 4% cement content. The samples met the conventional UCS values of (1500-3000 kN/m2) for base course of lightly trafficked roads while only sample A4 compacted at 10% cement content using WAS compactive effort met  the minimum (3000- 6000 kN/m2) for base course of highly trafficked road.  It is thus recommended that 4% cement should be used as an optimal content to stabilize the soils, if they are to be used as road construction materials

Stabilization of Soil with Cassava Peel Ash – Lime Admixture

This project examined the geotechnical properties of lateritic soils modified with Cassava Peel Ash-Lime admixture with a view to obtaining a cheaper and effective road stabilizer. After collecting samples 1, 2 and 3 from three borrow pits meant for road construction works, preliminary tests was performed on the samples for identification and classification purposes, followed by the consistency limit tests. Engineering property tests (compaction, California bearing ratio (CBR) and Unconfined Compressive Strength) was performed on both at the stabilized and unstabilized states with the addition of 2, 4, 6 and 8% Cassava Peel ash and 1%, 2% and 3% lime contents. The results showed that the soil samples were well graded sand with fair to poor rating as subgrade material for pavement construction. However, the engineering properties of the samples were further improved with the addition of Cassava Peel Ash-Lime Admixture. This caused reductions in the PI of samples 1 from 9% to 1% and 6%. Optimum values of maximum dry densities (MDD) and shear strengths were obtained at 4% for sample 1 and 3, 6% at sample 2 CPA+Lime stabilization. MDD increased to 1.680, 1.680 and 1.920 Mg/m3 respectively in samples A, B and C. We therefore concluded that Cassava Peel Ash-Lime Admixture has a good potential for improving the geotechnical properties of lateritic soils. Keywords: Cassava peel ash, Compaction, California bearing ratio, unconfined Compressive Strengt

The Potential of Bioethanol as a Viable Alternative to Fossil Fuels

Environmental challenges from fossil fuel emission have global issues and have contributed immensely to climate change. Bioethanol has experienced unprecedented level of attention due to its value as substitute to fossil fuel. Besides being a renewable and sustainable source of energy, it is also efficient, available and environmentally friendly. Global production of bioethanol continues to increase and will probably continue to dominate the alternative fuels market in the next decade. It is important to emphasize that for bioethanol to be a viable alternative, it must have ecological benefits, be economically competitive and its production must be in commercial scales without affecting the food production. This paper explains the problems and possible solutions in the production of bioethanol; since biofuel produces clean energy which can reduce the emission of CO2 into the atmosphere