ARBAMINCH UNIVERSITY INSTITUTE OF TECHNOLOGY EFFECT OF CEMENT ON ATTERBERG LIMITS AND COMPACTION CHARACTERSTICS OF EXPANSIVE SOILS( CASE OF KURAZ SUGAR DEVELOPMENT PROJECT) BY

Abstract

The characteristic of soft soil are high compressibility, low shear strength and low permeability. General construction problems in this deposit are insufficient bearing capacity, excessive post construction settlement and instability on excavation and embankment forming. Attempt to undertake construction in such formation result in bearing capacity failure, negative skin friction and also excessive deferential settlement.The conservative ground treatment methods such as soil replacement; advance pore water dissipation and platform settlements through the insertions of prefabricated vertical drains (PVD) and surcharge fills; modify subsoil bearing capacity through the installation of stone column or combination of these techniques are widely used throughout the world. Application of cement on to soil with low workability is supposed to provided improved Atterberg limits, compaction characteristics and strength; prevention of excessive settlement, enhanced construction period, replacement cost will be reduced. Sample preparation of the experimental work involved air and/or sun-drying, pulverization and sieving of soil to the required particle size. Classification of soil was determined by conducting index property and grain size analysis tests. Effect of cement on soilindex properties were assessed by conducting Atterberg limits test and strength properties were assessed by conducting compaction and UCS tests. Expansive clay soil were mixed with different proportion of cement(0, 2.5, 5, 7, 10%) by weight thoroughly then cured for 0, 7, 14 and 28 days followed by compaction, Atterberg limit and UCS tests.