International Journal of Advanced Engineering Research and Science (IJAERS) [Vol-4, Issue-11, Nov- 2017] https://dx.doi.org/10.22161/ijaers.4.11.4 ISSN: 2349-6495(P) | 2456-1908(O) www.ijaers.com Page | 28 Study of Mechanical Properties of Stabilized Lateritic Soil with Additives. Elijah O. Abe 1 , Ezekiel A. Adetoro 2 1,2 Department of Civil Engineering, the Federal Polytechnic, PMB 5351, Ado – Ekiti, Nigeria Abstract—The overdependence on the usage of industrially manufactured soil improved or conventional additives have resulted in unaffordable cost of construction of better infrastructure in Third World and poor countries which are mostly agriculturally dependent across Globe. This study is aimed at studying the mechanical properties of lateritic soil stabilized with mixture of conventional and locally available additives. Soil samples collected from the study area were subjected to laboratory tests (i.e. Grain Size and Atterberg Limits tests) after stabilized with cement, ESA and RHA additives at proportion of 2% to 10% by sample weight. It is observed that the LL, PL and PI values varied from 30.1% to 35.5%, 9.9% to 12.5% and 20.1% to 23.2% respectively for sample A. While LL, PL and PI values varied from 35.2% to 41.5%, 10.8% to 14.5% and 24.4% to 27.1% respectively for sample B. It could be generally observed that PI values reduced while PL values increased for the soil samples after increase in addition of cement additive from 6% to 8%. All the LL, PL and PI values also reduced as the percentage of RHA additive added increased. Soil sample A has group classifications of A – 2 – 6 while soil sample B has A – 7 and tend towards A – 2 - 6 and A - 6 after stabilization. The stabilization process using local additives as partial replacement of conventional one generally improved the soils Engineering properties. Though it is more felt in ESA than RHA. Further research work should be carried out. Keywords—Atterberg Limits, Grain Size Analysis, Mechanical Properties, Soil, Stabilization. I. INTRODUCTION As necessity is mother of all inventions, there is need for local alternative materials (i.e. local additives) to be used as partial or total replacement to conventional ones as stabilizing agents in order to cut or reduce cost of construction in Third World countries like Nigeria. Cement and lime have been the two main materials used for stabilizing soils for many years and have rapidly increase in prices due to the sudden increase in energy cost since almost half of a century. The over dependence on the usage of industrially manufactured soil improved or conventional additives (cement, lime, etc.) have resulted in rise in construction cost of roads and structures. This has continue to act as barrier for the Third World and poor countries across Globe to have access to good or better infrastructural amenities such roads and safe structures. Though, these countries are mostly agriculturally dependent ([3]). Since all structures are built on soil for stability, thus Soil stabilization is a significance aspect of Civil Engineering practices. Any deficiencies in soil characteristics will make it unsuitable for structure to be built on it – thus the need to either excavate the soil or improve its Engineering properties for maximum use. Excavation / replacement of soil is expensive and requires the use of heavy equipment. While Soil stabilization which has to do with improvement of Engineering properties of soil could be carried out through stabilizing agents / additives usage. Locally available additives such as Rice Husk Ash (RHA) and Egg Shell Ash (ESA) in partial replacement of Cement could be used. The overall cost of improving Engineering properties of soil using complete conventional additives (i.e. cement) in stabilization process could be high and unaffordable, but if partially replaced with locally available additives and are found suitable for stabilizing soil, this will reduce the cost of improving the Engineering properties of soil. These locally available additives could be agricultural wastes, industrial wastes, domestic wastes etc. Most of these wastes are hazardous to man and environment. Even burning them can deplete the ozone layer ([5]). The study area is along Ado Ekiti – Ijan road, Ado – Ekiti Local Government Area (LGA), Ekiti State as shown in Fig. 1 - a state in western Nigeria declared as a state on 1st October, 1996 alongside five others by the military under the dictatorship of General Sani Abacha. The state, carved out of the territory of old Ondo State, covers the former twelve local government areas that made up the Ekiti Zone of old Ondo State. On creation, it had sixteen Local Government Areas (LGAs), having had an additional four carved out of the old ones. One of these sixteen LGAs is Ado – Ekiti LGA. Ado - Ekiti is surrounded by Irepodun / Ifelodun LGA in the North, Gbonyin LGA in the East, Ekiti Southwest / Ikere LGAs in the West and Ise / Orun LGA in the South. The City itself is the Capital of Ekiti State and headquarters of Ado-Ekiti LGA ([9], [15]).