An assessment into the application if used lube-oil for improvement of engineering foundations.

Abstract

Lube Oil is used to mean Lubricating Oil as used in automobile engines for lubrication of moving parts, cooling, cleaning, corrosion control and is produced in fractional distillation in refinery processes. It is mainly used in the automotive industry but subsequent research with a view to its application for infrastructure development is necessary. The purpose of this study was to assess the suitability of used lube oil for improvement of engineering foundations as experimented on black cotton and red coffee soils. I was guided by the following specific objectives; to determine the fundamental properties of used engine oil, to explore the effect of used lube oil on the strength and engineering and index properties of the soils and to assess the effect of used lube oil on the permeability of soil. Soil improvement is the alteration of any property of a soil to improve its engineering performance through for instance; increased shear strength, reduced permeability and reduced compressibility. It results in improved durability of soil by increasing its strength and resistance to water. The improvement of black cotton soil and red coffee soils were the basis of this study by the application of Used Lube Oil in varying quantities at percentages of 0%, 5%, 10%, 15% and 20% by weight. The soils being highly sensitive to seasonal moisture content variations and are responsible for substantial distress to foundations and the structures that are built over them. When subjected to static and dynamic forces these soils heave and crack due to swelling and shrinkage. Hence, the soils are to be stabilized before construction in order to have efficient and long lasting foundations. The experimental study involved tests on Used Lube Oil using Red Wood Viscometer Test No 1-Universal for viscosity less than 2000 seconds (ASTM D445-06), classification and evaluation of the main index properties of the soil, compaction tests, California bearing ratio tests and permeability tests. The attempt was to investigate the limits within which Used Lube Oil can be used to improve black cotton soil and red coffee soil for engineering foundations and to xiii examine the effect of used lube oil on various geotechnical and engineering properties the methods used being the Red Wood Efflux Viscometer Test No.1-Universal, cone penetrometer test, compaction test, California bearing ratio test and permeability tests. Key test results were ;800kg/m3 density of used lube oil and 55mPa.s dynamic viscosity, an increase in the maximum dry densities of black cotton and red coffee soils up to 1655kg/m3 and 1523kg/m3 respectively at 10% Used Lube Oil; California bearing ration for black cotton soil and red coffee soil increased from 1 to 8 and 1 to 14 respectively with 10% used lube oil replacement; permeability for black cotton soil and red coffee soil increased to 3.73x10-7 and 5.93x10-7 ,respectively. This led to the conclusion that used lube oil increases maximum dry density, increases the California bearing ratio and increases permeability among other properties at 10% used lube oil replacement which is taken as the optimal value