TO IMPROVE THE STRENGTH AND CBR VALUES IN SUB-BASE AND SUB-GRADE IN EXPANSIVE SOILS USING CHLORIDE COMPOUNDS

Abstract

The improvement in the properties of expansive soils, as road subgrade stabilized with chloride compounds varying in percentages. Laboratory tests were undertaken to study the strength characteristics of expansive soils performed on natural soil samples. Expansive soils such as black cotton soils are basically susceptable to determinental volumetric changes, with changes in moisture. This behaviour of soil is attributed to the presence of mineral montmorillonite, which has an expanding lattice .Understanding the behaviour of expansive soil and adopting the appropriate control measures have been great task for the geotechnical engineers extensive research is going on to find the solutions to black cotton soils there have been many methods available to controlling the
expansive nature of the soils. An infrastructure project for instance Highways Railways, reclamation etc require earth material in very huge quantity. Fairly often large areas are covered with highly plastic and clayey soils. Extensive laboratory and field trials have been carried out by various researches and have shown promising results for application of such expansive soils after Stabilization. soft soils form problematic sub grade for pavements due to its low bearing capacity and strength. Pavement loads carrying on the soft sub grade soil may cause detrimental pumping actions. when they are located in areas with high water table which cause both construction and in service performance problems. The common solutions on encountering such problems include excavation and replacement of soils. By chemical stabilization with chlorides NACL, CACL2. On certain properties of soil such as OMC, MDD, UCC,
CBR has been studied under both heavy and light compaction. Hence in the present work experimentation is carried out to investigate the influence of chlorides including Nacl,Cacl2 on the engineering properties of expansive soils. Various amounts of salts (0.5%,1% ,1.5%,2.0%) were added to the soil to study the effect of salts on the compaction characteristics, consistency limits, compressive strength, ucsand cbr.The present investigation on expansive soils with chloride compounds