Abstrakt

Improvement of Sub Grade by Lime and Rice Husk Ash Admixturers

S.Chakraborty , S.P.Mukherjee , S.Chakrabarti , B.C.Chattopadhyay

The quality of a flexible pavement depends on the strength of its sub-grade soil. The strength of sub-grade is the major parameters for determining the thickness of pavement. In case of the flexible pavement the sub-grade must be uniform in terms of geotechnical properties like shear strength, compressibility etc. Materials selected for use in the construction of sub-grade must have to be of adequate strength and at the same time it must be economical for use. In view of the above the present investigation has been carried out with easily available materials like lime and rice husk ash mixed individually and also in combination with locally available clayey soil in different proportions at optimum moisture content (OMC). Since CBR is an important criterion in flexible pavement design, the strength improvement has been found in terms of CBR in the present study. The laboratory test results shows marked improvement of strength of soil with the addition of admixtures in respect of California Bearing Ratio (CBR) in unsoaked and soaked condition