Strength Characteristics And Application Prospects Of Treated Soil With Different Layered Combination

Abstract

newline Abstract newlineExpansive soils can absorb large amount of water and undergo high volume changes, newlinecausing seasonal swelling and shrinkage according to the availability of water. This newlineoften causes distress and failure of structures founded on such soils. Methods such as newlinepreloading, moisture control, replacement of affected soil, and additives have been used newlineto deal with the swelling problems associated with these soils. Literature reveals that newlinestudies were conducted to modify the behavior of expansive soils using additives such newlineas lime, cement, fly ash and other industrial wastes. newlineHowever, not many studies have been performed on the combined application of lime newlineand fly ash, particularly the layer formation with fly ash instead of expansive soils and newlinefly ash mixing. In this research work, attempt has been made to study the geotechnical newlinecharacteristics of expansive soil mixed and layered with different composition of fly newlineash and lime. The main focus of this study is to find meaningful application of waste newlinefly ash that does not qualify in construction industry and to use lime as an optimal newlinemodifier of properties wherever required. The geotechnical characteristics dealt in this newlinestudy include plasticity, compaction, durability, swelling, California bearing ratio, newlineunconfined compressive strength and load carrying strength. The variation of these newlineproperties due to mixing and layer formation addition of fly ash and fly ash-lime has newlinebeen systematically investigated. Here plasticity characteristics depict the modification newlinereaction occurring in the soil mix whereas the variation in strength characteristics newlineindicate modification and solidification reaction. newlineIt is noted that there is considerable influence of combined addition of fly ash-lime and newlineaging on geotechnical properties of expansive soil. In this study, a highly plastic newlineexpansive soil/ black cotton soil (BCS) was stabilized using fly ash (FA). The newlineexperimental investigations indicated a decrease in the plasticity index and free swell newlineindex of BCS FA mixes with an increase in FA content. Moreover, an increase in the newlineCalifornia bearing ratio of the BCS FA mix and layered BCS FA composite was newlineobserved. Further, bearing capacity tests were performed on subgrades prepared with newlineBCS FA layers and BCS FA mix with different percentage FA content. The detailed newlinemethodology adopted for theoretical and experimental investigations is presented, and newlinethe obtained results are critically evaluated. newlineii newlineSome of the properties like California bearing ratio and unconfined compressive newlinestrength are influenced much by fly ash-lime layered formation. The performance newlineenhancement of expansive soil due to combined addition of fly ash-lime and fly ash is newlineclearly discussed and quantified in this study. Based on the results, suggestions have newlinebeen made to maximize the utility of fly ash wherever possible. However, there are newlinesome chemical characteristics that need to be extensively investigated further for better newlineexplanation of certain trends observed in this study. newlineKeywords: expansive soil, fly ash, lime, soil stabilization, California bearing ratio, newlineunconfined compressive strength, plasticity, compaction, swelling