Stabilization Of Expansive Soil Using Lime And Saw Dust Ash (In Case Of Akaki Kality Area)

Abstract

Expansive Soils Are Highly Problematic Because They Undergo Uncontrolled Volumetric Changes Corresponding To Variations In Moisture Content. The Degree Of Expansiveness Depends On Whether The Soil Mass Contain Active Clay Minerals Or Not. Because Of This Alternate Swelling And Shrinkage, Structures Founded On Them Are Severally Damaged. The Presence Of The Smectite Group Of Minerals, Such As Montmorillonite, Illite, Vermiculite Is Mainly Responsible For The Swell And Shrinkage Behavior Of Expansive Soils Upon Varying The Moisture Content. They Are Poor Materials To Be Utilized In The Construction Of Highways, Air Fields, And Light Weight Structures, Because They Contain A Large Percentage Of Plastic Clay And Often Expansive, Swelling As Moisture Is Absorbed. Stabilization Of Expansive Soils With Stabilizers Controls The Potential Of Soils For A Change In Volume, And Improves The Strength Of Soils. The Utilization Of Locally Available Material Is Essential For The Sustainable And Economical Design Of Construction Projects Such As Roads, Railways And Buildings. In This Study, The Combined Effect Of Lime And Industrial Waste By-Product Of Sawdust Ash On Expansive Soil Properties Is Investigated To Control The Problems Posed By Expansive Soil.The Expansive Soil Sample Used For This Research Work Is Collected From Addis Ababa, Akaki Kality Sub City Around Tullu Dimtu Condominium Area. The Tests Was Performed On The Natural Black Cotton Soil, Black Cotton Soil Mixed With Lime And On Black Cotton Soil Mixed With Sawdust Ash And Optimum Amount Of Lime. Then Optimum Dosage Of Lime Was Obtained From The Laboratory Test Result Was Chosen Based On The Maximum Value Unconfined Compressive Strength Test Result By Mixing Expansive Soil With Lime Of 2%,3%,4% And 5%By Mass Of Soil. Since The Trial Mixes Showed That The Use Of 5 % Lime Gave Better Results, Then The Expansive Soil Added With Optimum Lime Content For Further Improve The Properties Of The Expansive Soil With 4%, 8 %, 12%, And 16 % Saw Dust Ash Were Analyzed. From The Analysis Of The Test Result, The Liquid Limit, Plastic Limit, Plasticity Index, And Free Swell And Maximum Dry Density Of The Soil Were Decreased While Optimum Moisture Content And Unconfined Compressive Strength Of Treated Soil Increased Upon Addition Of Additives. From The Study It Is Concluded That Treating Black Cotton Soil With Lime And Sawdust Ash And Improves The Properties Of The Expansive Soil.