Mollisols Soils Stabilization Using Lime Modified by Salts

Abstract

Mollisols are one of the most abundantly found natural surface soils in the world. Due to presence of high organic content in these soils, its geotechnical engineering characteristics like bearing capacity, settlement, and slope stability etc. are feeble. In this research, an attempt was made to propose the best methodology of chemical stabilization of mollisols to extend its applications in geotechnical engineering. Mollisols showed high organic content and their characteristics was obtained using X-Ray diffraction (XRD) test. The test indicated the presence of clay minerals (montmorillonite and kaolinite), organic matters (magnesium diisopropoxide, 9H-Flourine etc.) and organic acids (tartaric acid, formylvanillic acid etc.) in mollisols. The geotechnical engineering properties of mollisols including grain size analysis, Atterberg limits, maximum dry density, optimum moisture content and unconfined compressive strength were determined. Mollisols samples were stabilized with lime and varying percentages (up to 10 %) of three chloride salts i.e sodium chloride (NaCl), potassium chloride (KCl) and calcium chloride (CaCl2). The engineering classification of mixes remains unchanged by the addition of lime and salts. The results showed that when clay minerals were released from the affinity of organic matter and acids by addition of chloride salts, its reactivity with lime was enhanced resulting in improved stabilization. NaCl was observed to be the most promising chloride salt for effective stabilization of mollisols with lime.