Strength Behaviour of Expansive Soil Treated with Quarry Dust and Ferric Chloride

Abstract

The main objective of this investigation is to present the variations in index and engineering properties of expansive soil such as liquid limit, plastic limit, compaction characteristics, CBR and shear strength parameters when it is mixed with different percentages of Quarry dust (0, 5 and 10%) and Ferric chloride by dry weight of soil. Quarry dust has been chosen, as it is problematic to the environment and public due to its improper disposal. Quarry dust exhibits high shear strength, good permeability which is highly beneficial for its use as a geotechnical material. Ferric Chloride can be used because of its capability to easily exchange cations and ready dissolvability in water. Initially, expansive soil is mixed with different percentages of Quarry dust and Optimum percentage of Quarry dust were determined on the basis of Compaction and CBR tests. From the test results, it is observed that up to the addition of 5% of Quarry dust there is an increase in strength parameters such as Maximum Dry Density and California Bearing Ratio beyond that it is not effective. This investigation is further carried out by mixing Ferric chloride varying from 0 to 2% with an increment of 0.5% to the Quarry dust treated expansive soil (at its optimum 5%) and same series of experiments were conducted. From the results, it is observed that at optimum percentages, i.e. 5% Quarry dust and 1% ferric chloride, there is a marked improvement in the strength characteristics of soil.