Abstract: - India has a total road network of about 4.7millionkilometers. 53 percent of the total road network is paved. The budgeted amountspent over roads is Rs.14, 90,925 Crore. The durability and serviceability ofpavements depend mainly on strength of sub grade, which can be enhanced byground improvement techniques. The field of ground improvement by the use ofwaste rice husk ash for this purpose.. In recent times the demands for subgrade materials has increased due to increased constructional activities in the road sector and due to paucity ofavailable nearby lands to allow excavate fill materials for making sub grade.In this situation, a means to overcome this problem is to utilize the differentalternative generated waste materials, which cause not only environmentalhazards and also the depositional problems. Keeping this in view stabilizationof weak soil in situ may be done with suitable admixtures to save theconstruction costconsiderably.Also, due to the large production of agriculturalwastes, the world is facing a seriousproblem of its handling and disposal. The disposal of agricultural wastes has apotential negative impact on the environment causing air pollution, waterpollution and finally affecting the local ecosystems. So it is mandatory tomake these agricultural wastes eco- friendly. By using them as soilstabilizers, these agricultural wastes improve the strength of soil and itscharacteristics without causing any harm to the environment. The objective ofthis study is toupgrade soil as a construction material using Rice Husk Ash(RHA) and Sugar Bagasse Ash (SBA) which is a waste material. The cost ofconstruction of stabilized road have been keeping financially high due to the over dependency on the utilizationof industrially manufactured soil improving additives (cement, lime etc.). Byusing the agricultural waste the cost of construction will be considerablyreduced as well reducing the environmental hazards theycause. Silica producedfrom Rice Husk Ash and Sugar Bagasse Ash have investigated successfully as apozzolanic material in soil stabilization. Due tovarious construction development projects undertaken all over theworld there is a potential to use waste materials like Rice Husk and SugarBagasse which create disposal problems. Rice husk waste is produced in large quantity in rice husk mills and isdisposed in open land. Therefore use of rice husk in foundation of buildings and in road constructions to improve bearingcapacity of soil and to reduce the area of open land needed for its disposal andto preserve environment through resource conservation.
The performance of the soil- RHA and soil-SBA wasinvestigated with respect to Standard Proctor Test, Liquid Limit Test, PlasticLimit Test and California Bearing Ratio (CBR) test. The results obtained,indicates a considerable decrease in the maximum dry density (MDD), an increasein optimum moisture content (OMC) and a superficial improvement in the CBR withthe increase in the RHA and SBA content.
Keywords: - Plastic Limit Test, California Bearing Ratio (CBR) test, maximumdry density (MDD), Plastic limit